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Cochrane Database of Systematic Reviews Review - Intervention

Subacromial decompression surgery for rotator cuff disease

Authors' declarations of interest

Version published: 17 January 2019 Version history

https://doi.org/10.1002/14651858.CD005619.pub3
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Background

Surgery for rotator cuff disease is usually used after non‐operative interventions have failed, although our Cochrane Review, first published in 2007, found that there was uncertain clinical benefit following subacromial decompression surgery.

Objectives

To synthesise the available evidence of the benefits and harms of subacromial decompression surgery compared with placebo, no intervention or non‐surgical interventions in people with rotator cuff disease (excluding full thickness rotator cuff tears).

Search methods

We searched CENTRAL, MEDLINE, Embase, Clinicaltrials.gov and WHO ICRTP registry from 2006 until 22 October 2018, unrestricted by language.

Selection criteria

We included randomised and quasi‐randomised controlled trials (RCTs) of adults with rotator cuff disease (excluding full‐thickness tears), that compared subacromial decompression surgery with placebo, no treatment, or any other non‐surgical interventions. As it is least prone to bias, subacromial decompression compared with placebo was the primary comparison. Other comparisons were subacromial decompression versus exercises or non‐operative treatment. Major outcomes were mean pain scores, shoulder function, quality of life, participant global assessment of success, adverse events and serious adverse events. The primary endpoint for this review was one year. For serious adverse events, we also included data from prospective cohort studies designed to record harms that evaluated subacromial decompression surgery or shoulder arthroscopy.

Data collection and analysis

We used standard methodologic procedures expected by Cochrane.

Main results

We included eight trials, with a total of 1062 randomised participants with rotator cuff disease, all with subacromial impingement. Two trials (506 participants) compared arthroscopic subacromial decompression with arthroscopy only (placebo surgery), with all groups receiving postoperative exercises. These trials included a third treatment group: no treatment (active monitoring) in one and exercises in the other. Six trials (556 participants) compared arthroscopic subacromial decompression followed by exercises with exercises alone. Two of these trials included a third arm: sham laser in one and open subacromial decompression in the other.

Trial size varied from 42 to 313 participants. Participant mean age ranged between 42 and 65 years. Only two trials reported mean symptom duration (18 to 22 months in one trial and 30 to 31 months in the other), two did not report duration and four reported it categorically.

Both placebo‐controlled trials were at low risk of bias for the comparison of surgery versus placebo surgery. The other trials were at high risk of bias for several criteria, most notably at risk of performance or detection bias due to lack of participant and personnel blinding. We have restricted the reporting of results of benefits in the Abstract to the placebo‐controlled trials.

Compared with placebo, high‐certainty evidence indicates that subacromial decompression provides no improvement in pain, shoulder function, or health‐related quality of life up to one year, and probably no improvement in global success (moderate‐certainty evidence, downgraded due to imprecision).

At one year, mean pain (on a scale zero to 10, higher scores indicate more pain), was 2.9 points after placebo surgery and 0.26 better (0.84 better to 0.33 worse), after subacromial decompression (284 participants), an absolute difference of 3% (8% better to 3% worse), and relative difference of 4% (12% better to 5% worse). At one year, mean function (on a scale 0 to 100, higher score indicating better outcome), was 69 points after placebo surgery and 2.8 better (1.4 worse to 6.9 better), after surgery (274 participants), an absolute difference of 3% (7% better to 1% worse), and relative difference of 9% (22% better to 4% worse). Global success rate was 97/148 (or 655 per 1000), after placebo and 101/142 (or 708 per 1000) after surgery corresponding to RR 1.08 (95% CI 0.93 to 1.27). Health‐related quality of life was 0.73 units (European Quality of Life EQ‐5D, −0.59 to 1, higher score indicating better quality of life), after placebo and 0.03 units worse (0.011 units worse to 0.06 units better), after subacromial decompression (285 participants), an absolute difference of 1.3% (5% worse to 2.5% better), and relative difference of 4% (15% worse to 7% better).

Adverse events including frozen shoulder or transient minor complications of surgery were reported in approximately 3% of participants across treatment groups in two randomised controlled trials, but due to low event rates we are uncertain if the risks differ between groups: 5/165 (37 per 1000) reported adverse events with subacromial decompression and 9/241 (34 per 1000) with placebo or non‐operative treatment, RR 0.91 (95% CI 0.31 to 2.65) (moderate‐certainty evidence, downgraded due to imprecision). The trials did not report serious adverse events.

Based upon moderate‐certainty evidence from two observational trials from the same prospective surgery registry, which also included other shoulder arthroscopic procedures (downgraded for indirectness), the incidence proportion of serious adverse events within 30 days following surgery was 0.5% (0.4% to 0.7%; data collected 2006 to 2011), or 0.6% (0.5 % to 0.7%; data collected 2011 to 2013). Serious adverse events such as deep infection, pulmonary embolism, nerve injury, and death have been observed in participants following shoulder surgery.

Authors' conclusions

The data in this review do not support the use of subacromial decompression in the treatment of rotator cuff disease manifest as painful shoulder impingement. High‐certainty evidence shows that subacromial decompression does not provide clinically important benefits over placebo in pain, function or health‐related quality of life. Including results from open‐label trials (with high risk of bias) did not change the estimates considerably. Due to imprecision, we downgraded the certainty of the evidence to moderate for global assessment of treatment success; there was probably no clinically important benefit in this outcome either compared with placebo, exercises or non‐operative treatment.

Adverse event rates were low, 3% or less across treatment groups in the trials, which is consistent with adverse event rates reported in the two observational studies. Although precise estimates are unknown, the risk of serious adverse events is likely less than 1%.

PICOs

Population
Intervention
Comparison
Outcome

The PICO model is widely used and taught in evidence-based health care as a strategy for formulating questions and search strategies and for characterizing clinical studies or meta-analyses. PICO stands for four different potential components of a clinical question: Patient, Population or Problem; Intervention; Comparison; Outcome.

See more on using PICO in the Cochrane Handbook.

Surgery for rotator cuff disease

Background

The rotator cuff is a group of tendons that holds the shoulder joint in place allowing people to lift their arm and reach overhead. Some people can develop pain in their shoulder related to wear and tear of the rotator cuff. There may also be inflammation of the shoulder tendons or bursa (another part of the shoulder that helps it move), and pressure on the tendons by the overlying bone when lifting the arm up (impingement). Often the pain is made worse by sleeping on the affected shoulder and moving the shoulder in certain directions.

Surgery on your rotator cuff may include removing part of your bone to take the pressure off the rotator cuff tendons (acromioplasty), removing any swollen or inflamed bursa (the small sack of fluid that cushions the shoulder joint), and removing any damaged tissue or bone to widen the space where the tendons pass (subacromial decompression). Most rotator cuff surgery is now performed arthroscopically (surgical instruments are inserted through a small incision or key hole to perform surgery).

Study characteristics

This Cochrane Review is current to 22 October 2018. Trials were performed in hospitals in Denmark, Finland, Germany, Norway, Sweden and the UK. We included eight trials (1062 participants), comparing surgery with placebo (fake) surgery or other non‐operative treatment, such as exercise in people with impingement of the shoulder rotator cuff tendons.

The number of participants ranged from 42 to 313, mean age from 42 to 65 years, and duration of follow‐up from one year up to 12 to 13 years. Five trials failed to report funding sources, three received funding from non‐commercial foundations, and one trial author was paid by an instrument company.

Key results

Two trials (506 participants) met our criteria for inclusion for our main comparison, surgery versus placebo. Subacromial decompression resulted in little benefit to people at one‐year follow‐up.

Pain (lower scores mean less pain):

improved by 3% (3% worse to 8% better), or 0.26 points on a zero to 10 scale

• People who had placebo rated their pain as 2.9 points

• People who had surgery rated their pain as 2.6 points

Function (0 to 100; higher scores mean better function):

improved by 3% (1% worse to 7% better) or 3 points on a zero to 100 scale

• People who had placebo rated their function as 69 points

• People who had surgery rated their function as 72 points

Treatment success (much better or no problems at all):

5% more people rated their treatment a success (5% fewer to 16% more), or five more people out of 100

• 66 out of 100 people considered treatment as successful after placebo procedure

• 71 out of 100 people considered treatment as successful after surgery

Health‐related quality of life (higher scores mean better quality of life):

worsened 2% (8% worse to 4% better) or 0.02 points on a −0.59 to 1 scale

• People who had placebo rated their quality of life as 0.73 points

• People who had surgery rated their quality of life 0.71 points

Adverse events

1% fewer people (4% fewer to 3% more) had adverse events with surgery

• 4 out of 100 people reported adverse events after placebo

• 3 out of 100 people reported adverse event after surgery

Serious adverse events

No serious adverse events were reported in the trials. In observational studies the rate of serious adverse events was between 0.5% and 0.6%.

• 5 or 6 out of 1000 people had a serious adverse event after surgery

Certainty of the evidence

In people with painful shoulder impingement, high‐certainty evidence shows that subacromial decompression surgery does not improve pain, function or health‐related quality of life compared with placebo surgery, and moderate‐certainty evidence (downgraded due to imprecision), shows no improvement in the number of people reporting treatment success. We are uncertain if surgery is associated with more adverse events compared with no surgery.

Serious adverse events including deep infection, pulmonary embolism, nerve injury, and death can occur following shoulder surgery. Although precise estimates are unknown, the risk of serious adverse events is likely less than 1% (moderate‐certainty evidence, downgraded due to imprecision).

Authors' conclusions

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Implications for practice

The synthesis of data in this review does not support use of subacromial decompression surgery in the treatment of symptomatic rotator cuff disease presenting with impingement features and without full‐thickness rotator cuff tears. Subacromial decompression does not provide clinically important benefits compared with placebo surgery with respect to pain, function or quality of life, and this probably also applies to participant global assessment of treatment success. Although adverse events associated with subacromial decompression are probably low, serious adverse events such as deep venous thrombosis, pneumonia, peripheral nerve damage and death following arthroscopic shoulder surgery have been observed.

Participants in the trials experienced moderate pain and noticeable impaired function for up to one year but symptoms seemed to improve over the first two years of follow‐up. Therefore, people with rotator cuff disease should be informed that surgery will probably not improve their symptoms compared with exercises; they will likely experience shoulder pain and impaired function whether they have surgery or not, and this is likely to improve slowly over time irrespective of treatment.

Implications for research

Further research is unlikely to change the conclusions of this review. However, as one placebo‐controlled trial is still ongoing (Paavola 2018), and five‐year follow‐up will be completed in two years, we plan to update this review once the results are available.

If in the future we identify a clearly defined subpopulation, who may benefit from surgery, this should be tested in a well‐conducted placebo‐controlled trial.

Further trials comparing surgical decompression to exercises or no treatment are unlikely to change the conclusions of this review. Therefore, it is unlikely that we will include results from new or ongoing trials comparing subacromial decompression to exercise or no treatment in future review updates.

Summary of findings

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Summary of findings for the main comparison. Subacromial decompression compared to placebo surgery

Subacromial decompression compared to placebo surgery for people with impingement syndrome without full‐thickness rotator cuff tears

Patient or population: people with impingement syndrome without full‐thickness rotator cuff tears
Setting: hospitals in Finland and UK
Intervention: subacromial decompression
Comparison: placebo surgery (diagnostic arthroscopy)

Outcomes

Anticipated absolute effects* (95% CI)

Relative effect
(95% CI)

№ of participants
(studies)

Certainty of the evidence
(GRADE)

Comments

Risk with placebo surgery

Risk with subacromial decompression

Paina
(scale from 0‐10, 0 is no pain)
Follow‐up: 1 year

The mean pain was 2.9 pointsb

The mean pain was 0.26 points better
(0.84 better to 0.33 worse)

‐

284
(2 RCTs)

⊕⊕⊕⊕
High

Absolute difference 3% better (8% better to 3% worse); relative difference 4% better (12% better to 5% worse)c

Functional outcome

(Constant score from 0‐100, 100 is best)
Follow‐up: 1 year

The mean functional outcome was 69b

MD 2.76 higher
(1.36 lower to 6.87 higher)

274
(2 RCTs)

⊕⊕⊕⊕
High

Absolute difference 3% better (7% better to 1% worse); relative difference 9% better (22% better to 4% worse)c

Global assessment of treatment success

655 per 1000

708 per 1000
(610 to 832)

RR 1.08
(0.93 to 1.27)

290
(2 RCTs)

⊕⊕⊕⊝
Moderated

Absolute difference 5% more reported success (5% fewer to 16% more); relative difference 8% more reported success (7% fewer to 27% more)

Health‐related quality of life
(scale from −0.59 to 1, 1 is perfect health)
Follow‐up: 1 year

The mean health‐related quality of life was 0.73b

MD 0.03 lower
(0.11 lower to 0.06 higher)

285
(2 RCTs)

⊕⊕⊕⊕
High

SMD 0.09 worse (0.39 worse to 0.21 better)

Absolute difference 2% worse (7% worse to 4% better); relative difference 5% worse (20% worse to 11% better)c

Adverse events

37 per 1000

34 per 1000
(11 to 98)

RR 0.91
(0.31 to 2.65)

406
(2 RCTs)d

⊕⊕⊕⊝
Moderatee

Absolute difference of 1% fewer events with surgery (4% fewer to 3% more); relative difference 9% fewer events with surgery (69% fewer to 165% more)

Serious adverse events

No events

No events

No estimate

331
(2 RCTs)

⊕⊕⊕⊝
Moderatef

Although precise estimates are unknown, serious adverse event rates in observational studies are reported as less than 1%g

*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).

CI: confidence interval; MD: mean difference; RR: risk ratio; SMD: standardised mean difference

GRADE Working Group grades of evidence
High certainty: we are very confident that the true effect lies close to that of the estimate of the effect.
Moderate certainty: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different.
Low certainty: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect.
Very low certainty: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect.

aPain measured with numeric rating scale (NRS) or visual analogue scale (VAS).
bMedian value in placebo groups after one‐year follow‐up.
cRelative changes calculated relative to baseline in control group (i.e. absolute change (mean difference) divided by mean at baseline in the placebo group from Paavola 2018 (values were: 7.23 points on 0 to 10‐point VAS pain; 31.7 points on 0 to 100‐point Constant score) and Beard 2018 (0.55 points on EQ‐5D quality‐of‐life scale). Absolute change calculated as mean difference divided by scale of the instrument, expressed as percentage.

dPooled both placebo and non‐operative (exercise or no treatment) comparisons from randomised controlled trials in the analysis of adverse events
eDowngraded due to imprecision (due to low event rates, or 95% confidence intervals that included both benefits and harms) in the randomised trials.

fDowngraded due to indirectness as arthroscopic procedures other than subacromial decompression were included in the surgery registry observational data
gSerious adverse events as reported in observational studies, 7 per 1000 (95% CI 6 to 8 per 1000) include: deep infection; pulmonary embolism; uncontrolled bleeding; myocardial infection; acute renal failure; ventilation more than 48 hours; cerebral vascular incident; septic shock; cardiac arrest; wound dehiscence; deep venous thrombosis; pneumonia; bleeding requiring transfusion; nerve injury; death; organ space infection.

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Summary of findings 2. Subacromial decompression compared to exercises

Subacromial decompression compared to exercises for people with impingement syndrome without full‐thickness rotator cuff tears

Patient or population: people with impingement syndrome without full‐thickness rotator cuff tears
Setting: hospitals or home
Intervention: subacromial decompression
Comparison: exercises

Outcomes

Anticipated absolute effects* (95% CI)

Relative effect
(95% CI)

№ of participants
(studies)

Certainty of the evidence
(GRADE)

Comments

Risk with exercise

Risk with subacromial decompression

Paina
(scale from: 0‐10, 0 is no pain)
Follow‐up: 1 year

The mean pain was 3.7 pointsb

MD 1.01 better
(1.6 better to 0.42 better)

‐

316
(3 RCTs)

⊕⊕⊝⊝
Lowc

Absolute difference 10% better (4% better to 16% better); relative difference 14% better (6% better to 22% better)d

Functional outcomee

(scale from 0‐100, 100 is best)
Follow‐up: 1 year

The mean functional outcome was 58b

MD 3.24 better
(8.08 worse to 14.55 better)

‐

259
(3 RCTs)

⊕⊕⊝⊝
Lowc

Absolute difference 3% better (8% worse to 15% better); relative difference 9% better (23% worse to 41% better)d

Global assessment of treatment success

598 per 1000

723 per 1000
(574 to 902)

RR 1.21
(0.96 to 1.51)

158
(2 RCTs)

⊕⊕⊝⊝
Lowc

Absolute difference 13% more reported success (2% fewer to 30% more); relative difference 21% more reported success (4% fewer to 51% more)

Health‐related quality of life

(15D; scale from: 0‐1, 1 is perfect health)
Follow‐up: 1 year

The mean health‐related quality of life was 0.91b

MD 0.01 better
(0.01 worse to 0.03 better)

‐

116
(1 RCT)

⊕⊕⊝⊝
Lowc

Absolute difference 1% better (1% worse to 3% better); relative difference 1% better (1% worse to 3% better)d

Adverse events

37 per 1000

34 per 1000
(11 to 98)

RR 0.91
(0.31 to 2.65)

406
(2 RCTs)f

⊕⊕⊕⊝
Moderateg

Absolute difference of 1% fewer events with surgery (4% fewer to 3% more); relative difference 9% fewer events with surgery (69% fewer to 165% more)

Serious adverse events

No events

No events

Not estimable

⊕⊕⊕⊝
Moderateh

Although precise estimates are unknown, serious adverse events rates in observational studies are reported as less than 1%i

*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).

CI: confidence interval; MD: mean difference; RR: risk ratio

GRADE Working Group grades of evidence
High certainty: we are very confident that the true effect lies close to that of the estimate of the effect.
Moderate certainty: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different.
Low certainty: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect.
Very low certainty: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect.

aPain measured with numeric rating scale (NRS) or visual analogue scale (VAS).
bMedian value in exercise groups at one‐year follow‐up.
cDowngraded due to risk of bias and imprecision.
dRelative changes calculated as mean difference divided by mean at baseline in the exercise group from Paavola 2018 (mean (standard deviation) values were: 7.24 (2.08) points on 0 to 10‐point VAS pain scale; 35.2 (16.2) points on 0 to 100‐point Constant score); and 0.88 (0.08) points on 0 to 1 scale in health‐related quality of life. Absolute difference calculated as mean difference divided by scale of the instrument, expressed as percentage.
eFunctional outcome measured with various measures (Constant score, Shoulder Disability Questionnaire, Subjective Shoulder Rating scale, or Neer score).

fPooled both placebo and non‐operative (exercise or no treatment) comparisons from randomised controlled trials in the analysis of adverse events

gDowngraded due to imprecision (due to low event rates) in the randomised trials
hDowngraded due to indirectness as arthroscopic procedures other than subacromial decompression were included in the surgery registry observational data.
iSerious adverse events as reported in observational studies, 7 per 1000 (95% CI 6 to 8 per 1000) include: deep infection; pulmonary embolism; uncontrolled bleeding; myocardial infection; acute renal failure; ventilation more than 48 hours; cerebral vascular incident; septic shock; cardiac arrest; wound dehiscence; deep venous thrombosis; pneumonia; bleeding requiring transfusion; nerve injury; death; organ space infection.

Background

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This Cochrane Review is one of an updated series of Cochrane Reviews of interventions for shoulder disorders. The original review on all interventions for shoulder pain (Green 1998), has been split into a series of reviews that examine interventions for different shoulder disorders separately. The last review on surgery for rotator cuff disease was published in Issue 1, 2008 (up to date to 3 September 2006; Coghlan 2008). For this update we have split the surgery for rotator cuff disease review into three reviews: 1) subacromial decompression surgery for rotator cuff disease (the topic of this review); 2) surgery for full‐thickness rotator cuff tears; and 3) surgery for calcific rotator cuff tendinopathy. A parallel systematic review was performed by an overlapping team of authors (Lähdeoja 2019), and both reviews informed the 13th BMJ Rapid Recommendations on the same topic (Vandvik 2018).

Estimates of the lifetime and monthly prevalence of shoulder pain in the general population vary between 6.7% and 66.7% and 18% to 31% respectively (Luime 2004). Shoulder pain is the third most common musculoskeletal complaint presenting to primary care (Rekola 1993). Each year about 1% of the population 45 years and older presents with shoulder pain to primary care settings (Royal College of General Practitioners 1980‐81). The direct annual healthcare costs attributable to shoulder disorders was estimated to be USD 7 billion in the USA in 2000 (Johnson 2004). Rotator cuff disorders are the most common underlying cause, with estimates varying between 65% and 85% depending upon the setting and age of the study population (Chard 1991; Ostör 2005; Vecchio 1995). Subacromial decompression surgery is increasingly performed for rotator cuff disorders (Vitale 2010). For example, a UK study reported a seven‐fold increase in people undergoing this procedure between 2000 (2523 people) and 2010 (21,355 people; Judge 2014), while in the USA an estimated 257,541 (95% CI 185,268 to 329,814) shoulder arthroscopies, excluding those for cuff repairs, were performed in 2006 (Jain 2014).

Description of the condition

A confusing array of diagnostic labels are used for pathology affecting the rotator cuff and related structures (Whittle 2015). We prefer to use the umbrella term 'rotator cuff disease' as a simple categorisation that encompasses all symptomatic disorders of the rotator cuff, regardless of mechanism (inflammatory, degenerative or acute injury), or precise anatomical location (e.g. supraspinatus tendon versus subacromial bursa; Buchbinder 1996). Diagnoses included within this umbrella term include rotator cuff tendinopathy or tendinitis, the impingement syndrome, partial and complete rotator cuff tears and complete rotator cuff tear, calcific tendinitis, and subacromial bursitis.

People with symptomatic rotator cuff disease present with shoulder pain, often described as pain in the upper outer arm. It is aggravated by overhead activities and is often worse at night and lying on the affected side, leading to disrupted sleep. The pain is accompanied by loss of function and often significant disability. A painful arc (as the arm is passively abducted away from the body, pain occurs between 60° and 120°) is nearly always present. Its presence is associated with a positive likelihood ratio of 3.7 (CI 1.9 to 7.0), while its absence is associated with a negative likelihood ratio of 0.36 (CI 0.23 to 0.54; Hermans 2013).

The current tenet proposes that rotator cuff disease is an interaction between mechanistic and biological factors. Mechanistic theory postulates that the mechanical impingement occurs between undersurface of anterior acromion, coracoacromial ligament, and humerus during shoulder flexion or abduction. According to the theory, pathophysiology starts from oedema and thickening of bursa (stage 1). It progresses to fibrosis and inflammatory changes (stage 2), and eventually to partial or complete tear of the tendon (stage 3; Neer 1983). Trauma may also cause the tear but often it is absent. A tear causes imbalance in the forces moving the shoulder joint, which may further aggravate the pathology and symptoms (Nam 2012). Once a tear develops, it does not heal spontaneously (Yamaguchi 2001). The shape of the acromion and fatigue or imbalance of muscular strength in the rotator cuff muscles has also been postulated to predispose to subacromial impingement (Chen 1999).

Several observations support the mechanistic theory including the location of tears and their increasing prevalence with increasing age (Neer 1983). Anatomical and imaging studies have shown an association between the shape of the acromion and presence of a tear (Moor 2014). Finally, higher prevalence in the dominant side (Shiri 2007) and experimental pressure measurements (Hyvonen 2003) imply that rotator cuff disease is associated with mechanical factors.

Biological studies also offer a framework to explain the condition. Ageing predisposes tendons to tendinopathy, which could explain the observed increasing prevalence in middle age (Teunis 2014). Histological studies have associated rotator cuff tears with several cellular and extracellular changes affecting the structure of the tendon (Dean 2012), but the exact biological mechanism causing the pain remains elusive. Taken together, current evidence suggest that the cause for rotator cuff disease appears to be an interplay between degenerative, metabolic and mechanical factors. It is so common after middle age (Minagawa 2013; Yamamoto 2010), that some consider it part of normal ageing.

Description of the intervention

Surgical procedures that may be used to treat rotator cuff disease include subacromial decompression (acromioplasty/bursectomy), or debridement of partial tears or a rotator cuff repair, or both. Operation may be performed by an open approach, arthroscopic‐assisted (mini‐open) technique, or as an arthroscopy only procedure (Nho 2007). Arthroscopic surgery may result in less morbidity and shorter recovery time enabling earlier return to work or sport (Coghlan 2008; Hata 2001).

Patients typically wear a sling after surgery for one to three weeks and undergo postoperative rehabilitation for three to six months (Hertling 1990; Millett 2006; Van der Meijden 2012). The principles of postoperative physical therapy are similar to those for physical therapy alone except for use of the sling, and the exercise programme must often be adjusted due to postoperative pain in the immediate postoperative period.

Potential risks of surgery include complications related to the anaesthesia or comorbidities, infection, postoperative adhesive capsulitis (or frozen shoulder), peripheral nerve injury, ongoing pain, and even death.

Non‐operative treatment includes physical therapies such as muscle strengthening, scapular stabilisation, and stretching and flexibility exercises (Bennell 2007; Hertling 1990; Kuhn 2009; Misamore 1995; Page 2016), glucocorticoid injection, nonsteroidal anti‐inflammatory drugs (NSAIDs), acupuncture, iontophoresis, phonophoresis, transcutaneous electrical nerve stimulation (TENS), pulsed electromagnetic field (PEMF), topical glyceral trinitrate and ultrasound (Buchbinder 2003; Buchbinder 2011; Cumpston 2009; Engebretsen 2009; Gialanella 2011; Green 2005; Page 2016a; Pedowitz 2012). The benefits of many of these treatments have not been established in high‐quality, randomised, placebo‐controlled trials.

How the intervention might work

As described above, the mechanistic theory contends that impingement symptoms occur primarily due to repetitive compressive and shearing forces on the rotator cuff tendons. Subacromial decompression therefore aims to remove the inflamed subacromial bursa and reduce compressive forces by removing bone from the anterior/lateral undersurface of the acromion. Widening of the space for the traversing tendons in this way is believed to halt the pathological process.

Why it is important to do this review

As we have outlined, rotator cuff disease has substantial economic and quality‐of‐life implications for the patient and healthcare systems, and the numbers of people undergoing subacromial decompression surgery are rapidly rising. Surgery predisposes the patient to risks related to surgery, thus its use has to be supported by evidence of its benefit. Despite a mechanistic theory supporting surgery, improvements can also occur in the absence of surgery.

Our 2008 Cochrane Review identified 14 randomised controlled trials (RCTs) involving 829 participants (Coghlan 2008). Eleven trials included participants with impingement, two trials included participants with rotator cuff tear and one trial included participants with calcific tendinitis. The trials examined heterogeneous interventions and were all susceptible to bias, limiting our ability to draw firm conclusions about the benefits and harms of surgery for rotator cuff disease. For the treatment of impingement, there was moderate‐certainty evidence, based upon three trials, of no significant differences in outcome between open or arthroscopic subacromial decompression versus active non‐operative treatment (exercise programme, physiotherapy regimen of exercise and education, or graded physiotherapy strengthening program) for the treatment of impingement. There was moderate‐certainty evidence from six trials that there were no clinically important differences in outcome between arthroscopic and open subacromial decompression although four trials reported earlier recovery with arthroscopic decompression.

Since the last published version of this review, two additional RCTs assessing the benefits and harms of surgery for rotator cuff disease have been published. Both trials investigated decompression for people with rotator cuff disease excluding full‐thickness tears, and both included a placebo surgery control group (Beard 2018; Paavola 2018). Therefore an updated review of the available evidence is timely.

Objectives

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To synthesise the available evidence of the benefits and harms of subacromial decompression surgery compared with placebo, no intervention or non‐surgical interventions in people with rotator cuff disease (excluding full thickness rotator cuff tears).

Methods

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Criteria for considering studies for this review

Types of studies

We included RCTs of any design (e.g. parallel, cross‐over, factorial), controlled clinical trials using a quasi‐randomised method of allocation (methods of allocating participants to a treatment that are not strictly random, e.g. date of birth, hospital record number or alternation). Reports of trials were eligible regardless of the language, date of publication, or publication status.

For harms, we also included prospective observational studies from surgery regsitries designed to record harms from subacromial decompression or shoulder arthroscopy for mixed diagnoses including impingement symptoms.

Types of participants

We included trials that enrolled adults (aged 18 years and over) with rotator cuff disease, confirmed by clinical history, physical examination, magnetic resonance imaging (MRI), ultrasound or arthrogram. We excluded trials that included participants with full‐thickness tears, unless it was a minority of participants (< 20%). We excluded studies of adults undergoing surgery for benign or malignant tumours, adhesive capsulitis, shoulder instability, joint replacement or fractures. For the harms, there were no restrictions regarding the diagnoses of participants.

Types of interventions

Subacromial decompression surgery (open or arthroscopic bursectomy and/or acromioplasty) versus placebo, non‐operative treatment, or no treatment were included. For this update, as the benefit of surgery over placebo, or non‐surgical treatment is not yet established, we excluded studies comparing one type of surgical technique to another. We also excluded studies only assessing different surgical devices (such as comparing two types of suture materials or techniques) or biologics.

Comparators could include the following.

  • Placebo surgery

  • Non‐operative treatments, including physical therapy, exercises, pharmacologic interventions such as NSAIDs and/or glucocorticoid or other injections

  • Wait and see/no or delayed treatment

Types of outcome measures

We ensured that the outcomes in our review were consistent with The Outcome Measures in Rheumatology (OMERACT) draft core domain set for clinical trials of shoulder disorders (Buchbinder 2017).

Major outcomes

We included the following outcomes.

  • Overall pain (mean or mean change measured by visual analogue scale (VAS), numeric or categorical rating scale). If trials did not measure overall pain, we planned to include other pain measures highest on the following hierarchy: unspecified pain, pain with activity, pain at night or at rest.

  • Physical function. Where trial authors reported outcome data for more than one function scale, we extracted data on the scale that was highest on the pre‐defined list below. These questionnaires generally include several domains, such as pain, function, range of motion and strength, and provide a shoulder‐specific composite score. Our hierarchy was based upon the most commonly used scores used in trials assessing surgery, given that there is a paucity of research to inform us which measure is the gold standard (Page 2015).

    • Constant Murley Score

    • Shoulder Pain and Disability Index (SPADI)

    • Oxford Shoulder Score (OSS)

    • American Shoulder and Elbow Surgeons Standardized Form (ASES‐SF)

    • UCLA Shoulder Score

    • Disabilities of the Arm, Shoulder and Hand (DASH)

    • Shoulder Disability Questionnaire (SDQ)

    • any other shoulder function scale.

  • Participant global assessment of treatment success as defined by the trial authors (e.g. proportion of participants with significant overall improvement). See also Differences between protocol and review.

  • Health‐related quality of life, measured by generic tools (such as components of the Short Form‐36 (SF‐36), SF‐12, EQ‐5D, 15D) or disease‐specific tools.

  • Number of participants experiencing adverse events, extracted from randomised trials (including neurovascular complications, infections, postoperative shoulder stiffness/adhesive capsulitis (frozen shoulder)

  • Number of participants experiencing a serious adverse event, extracted from surgical registries. We defined serious harms as death, bleeding (uncontrolled or requiring transfusion), cardiac arrest requiring cardiopulmonary resuscitation, myocardial infarction, cerebrovascular accident, acute renal failure, unplanned intubation, requiring ventilator for more than 48 hours, deep infection (surgical site or organ/space), sepsis, septic shock, pneumonia, wound dehiscence, pulmonary embolism, deep vein thrombosis or peripheral nerve injury.

Minor outcomes

  • Participation (recreation and work)

  • Treatment failure (e.g. progression to full‐thickness tear)

Timing of outcome assessment

We extracted outcomes at the following time points.

  • Up to and including three months

  • Three months up to six months

  • Greater than six months up to one year

  • Greater than one year up to two years

  • Greater than two years up to five years

  • Greater than five years

We extracted the latest time point within the time period if there were multiple time points at which outcomes were measured (i.e. if a study reported outcomes at 6 weeks and 4 months and 12 months, we extracted outcomes at 4 months (to 6‐month analysis), and 12 months. The primary time point was one year.

Search methods for identification of studies

Electronic searches

This current review update includes studies published between March 2006 and 22 October 2018. We searched the following databases for randomised or quasi‐randomised trials.

Searching other resources

We used the data from Lähdeoja 2019, who summarised serious adverse events from arthroscopic shoulder surgery registries.

We also reviewed the reference lists of the included trials and any relevant review articles retrieved from the electronic searches, to identify any other potentially relevant trials.

Data collection and analysis

Selection of studies

Three review authors (TK, NBJ and CP) independently selected trials for possible inclusion against a predetermined checklist of inclusion criteria (see Criteria for considering studies for this review). We screened titles and abstracts and initially categorised studies into the following groups.

  • Possibly relevant: trials that met the inclusion criteria and trials from which it was not possible to determine whether they met the criteria either from their title or abstract

  • Excluded: those clearly not meeting the inclusion criteria

If a title or abstract suggested that the trial was eligible for inclusion, or we could not tell, we obtained a full‐text version of the article, and two to three review authors (TK, NBJ and CP) independently assessed it to determine whether it met the inclusion criteria. The review authors resolved discrepancies through discussion or adjudication by a fourth author (RB).

For harms, we included the studies identified in the parallel systematic review (Lähdeoja 2019).

Data extraction and management

Two of three review authors (TK NBJ, CP) independently extracted the following data from the included trials.

  • Trial characteristics, including design (e.g. parallel or cross‐over), country, sample size calculation, primary analysis, source of funding, and trial registration status (with registration number recorded if available)

  • Number of participants, inclusion/exclusion criteria, participant characteristics, including age, sex, duration of symptoms, outcomes at baseline and details regarding the cuff tear if present

  • Intervention characteristics for each treatment group, and use of co‐interventions

  • Outcomes reported, including the measurement instrument used and timing of outcome assessment

When additional data were required, we contacted the trial authors to obtain this. Where data were imputed or calculated (e.g. standard deviations calculated from standard errors, P values, confidence intervals, imputed from graphs, from standard deviations in other trials), we reported this in the Notes section of Characteristics of included studies. We resolved any disagreements and issues by consultation with RB.

To prevent selective inclusion of data based on the results, we used the following a priori defined decision rules to select data from trials.

  • Where trial authors reported both final values and change from baseline values for the same outcome, we extracted final values.

  • Where trial authors reported both unadjusted and adjusted values for the same outcome, we extracted unadjusted values.

  • Where trial authors reported data analysed based on the intention‐to‐treat (ITT) sample and another sample (e.g. per‐protocol, as‐treated), we extracted ITT‐analysed data.

  • For cross‐over RCTs, we preferentially extracted data from the first period only.

We used a priori hierarchies (see Types of outcome measures) to choose the outcome for each domain if the trial measured one outcome with several instruments.

When trial authors had used different scales, we transformed the scales to match the most commonly used instrument scale before pooling, and reversed the scale if needed to make it comparable to the most commonly used instrument (see Measures of treatment effect).

Serious adverse events from surgical registries: two review authors (TL and CA) extracted the study characteristics and the event rates. We solved any discrepancies by consensus.

Assessment of risk of bias in included studies

Pairs of authors (TK, RJ, CP, NBJ, TL or CA), assessed the risk of bias of each included trial and resolved any disagreements by consensus, or consultation with RB where necessary.

We assessed the following methodological domains, as recommended by Cochrane (Higgins 2017):

  • sequence generation;

  • allocation sequence concealment;

  • blinding of participants and study personnel;

  • blinding of outcome assessment (assessed separately for self‐reported and objectively assessed outcomes);

  • incomplete outcome data;

  • selective outcome reporting;

  • other potential source of bias: in this bias we judged whether the number of cross‐overs from placebo or from exercise therapy to surgery might bias the analysis.

We rated each item as being at 'low risk', 'unclear risk' or 'high risk' of bias.

For observational studies reporting serious adverse events, for assessing risk of bias we used methods described in Hayden 2013:

  • study participation;

  • study attrition;

  • prognostic factor measurement;

  • outcome measurement;

  • study confounding;

  • statistical analysis and reporting

Measures of treatment effect

We used the Cochrane statistical software, Review Manager 5.3 to perform data analysis (Review Manager 2014). For dichotomous outcomes, we expressed the difference as risk ratios (RRs) with 95% CIs. For continuous data, we expressed results as mean differences (MD) with 95% confidence intervals when the same measurement tool was used across studies or standardised mean difference (SMD) when the same outcome was measured using different instruments.

Where trials used different measures for the same outcome or concept, we used the most common outcome measure as an index outcome measure. We transformed MDs and standard deviations (SDs) of other outcome measures to the scale of the index instrument and pooled the data using MD as the summary estimate, according to the methods of Thorlund 2011. For pain, we assumed VAS and numeric rating scale (NRS) were comparable scales, and transformed 1 to 9 (Haahr 2005) and 1 to 10 (Brox 1993) to a zero to 10 scale. The trials used various functional measures (Constant score, shoulder disability score, subjective shoulder rating scale, and Neer score), but as these were all measured in 0 to 100 scale, no transformation was necessary except for reversal of shoulder disability score used by Ketola 2009.

When large variations in SDs led to problematic weights in the meta‐analysis, we pooled SMDs. In this case, we back‐transformed SMDs to a typical scale (e.g. 0 to 100 for function), by multiplying the SMD by a typical among‐person standard deviation (e.g. the SD of the control group at baseline from the most representative trial; as per Chapter 12 of theCochrane Handbook for Systematic Reviews of Interventions (Schünemann 2017a)). This method was only required for the quality‐of‐life outcome. For this outcome, we used an SD of 0.28 (EQ‐5D index), taken from Beard 2018 in the primary analysis (Analysis 1.4) and SD of 0.07 (15D) taken from Paavola 2018 in the secondary analysis (Analysis 2.4).

In the Comments column of the 'Summary of findings' tables, we reported the absolute percent difference, the relative percent change from baseline, and for outcomes that show a clinically important difference between treatment groups, we reported the number needed‐to‐treat for an additional beneficial outcome (NNTB), or number needed‐to‐treat for an additional harmful outcome (NNTH).

For dichotomous outcomes we planned to calculate the NNTB or NNTH from the control group event rate and the risk ratio using the Visual Rx NNT calculator (Cates 2008). As there were no clinically important differences in the analyses, we did not calculate the NNTB for continuous measures.

For dichotomous outcomes, we calculated the absolute difference from the difference in the risks between the intervention and control group, as calculated in GRADEpro GDT (GRADEpro GDT 2015), and expressed as a percentage. We calculated the relative percent change as the RR minus 1 and expressed as a percentage. For continuous outcomes, we calculated the absolute difference as the MD divided by the scale and expressed as percentage. We calculated the relative difference (RD) as the absolute benefit (MD) divided by the baseline mean of the control group, expressed as a percentage.

For harms, we calculated incidence proportions using a generalised linear model, using a binomial distribution and an identity link function.

Unit of analysis issues

The unit of analysis was the participant for all trials. For studies containing more than two intervention groups, making multiple pair‐wise comparisons between all possible pairs of intervention groups possible, we included the same group of participants only once in the meta‐analysis

Dealing with missing data

When required, we contacted trial authors to obtain data that were missing from the trial reports. For continuous outcomes (pain and disability), we calculated the weight of the trial using the number of participants analysed at that time point. If the number of participants analysed was not presented for each time point, we used the number of randomised participants in each group at baseline. For dichotomous outcomes, we used the final data for the events reported in each trial.

For continuous outcomes with no SD reported, we calculated SDs from standard errors (SEs), 95% confidence intervals (CIs) or P values. If we could not obtain any measurement of variance from the trial reports or by contacting the authors, we imputed the SD from the most representative trial. Where we imputed or calculated data (e.g. SDs calculated from SEs, 95% CIs or P‐values, or imputed from graphs or from SDs in other trials), we reported this in the Characteristics of included studies tables.

Assessment of heterogeneity

We assessed clinical diversity by determining whether the characteristics of participants, interventions, outcome measures and timing of outcome measurement were similar across trials. We assessed statistical heterogeneity using the I2 statistic (Higgins 2003). We interpreted the I2 statistic using the following as an approximate guide:

  • 0% to 40% might not be important;

  • 30% to 60% may represent moderate heterogeneity;

  • 50% to 90% may represent substantial heterogeneity;

  • 75% to 100% considerable heterogeneity (Deeks 2017).

Assessment of reporting biases

To assess small study effects, we planned to generate funnel plots for meta‐analyses including at least 10 trials of varying size. If we detected asymmetry in the funnel plots, we planned to review the characteristics of the trials to assess whether the asymmetry was likely due to publication bias or other factors, such as methodological or clinical heterogeneity of the trials (Sterne 2011).

To assess outcome reporting bias, we compared the outcomes specified in trial protocols with the outcomes reported in the corresponding trial publications; if trial protocols were unavailable, we compared the outcomes reported in the methods and results sections of the trial publications (Dwan 2011; Kirkham 2010).

Data synthesis

We defined the following review questions.

For people with rotator cuff disease (without full‐thickness tears):

  • is subacromial decompression surgery more effective than placebo surgery?

  • is subacromial decompression surgery more effective than physical therapy or rehabilitation or exercises alone?

  • is subacromial decompression surgery more effective than no treatment?

Surgery could be followed by postoperative physical therapy or rehabilitation or an exercise program.

For benefit, we considered the first comparison, subacromial decompression versus placebo, to be the least prone to bias and it was therefore the primary comparison for addressing the objectives of this review.

For adverse events, as we expected the results to be similar for both placebo and non‐operative comparisons (exercise or no treatment), to simplify the presentation we presented these data in the same analyses.

We combined results of trials with similar characteristics (participants, interventions, outcome measures and timing of outcome measurement) to provide estimates of benefits and harms. We pooled outcomes using the random‐effects model as a default based on the assumption that clinical and methodological heterogeneity was likely to exist and to have an impact on the results.

GRADE and 'Summary of findings' tables

We presented the six major outcomes (pain, function, global assessment of success, health‐related quality of life, adverse events, serious adverse events) of the review in 'Summary of findings' tables, which summarise the certainty of evidence, the magnitude of effect of the interventions examined, and the sum of available data on the outcomes as recommended by Cochrane. The summary of findings table includes an overall grading of the evidence related to each of the main outcomes, using the GRADE approach (Schünemann 2017b).

We planned two tables, one for surgery versus placebo and one for surgery versus exercise.

Pairs of review authors (TK, TL, CA, RJ and RB), assessed the certainty of the evidence as high, moderate, low, or very low using the five GRADE considerations (study limitations, consistency of effect, imprecision, indirectness and publication bias) to assess the body of evidence that contributes data to the meta‐analyses for the prespecified outcomes (Schünemann 2017a). We used GRADEpro software to prepare the 'Summary of findings' tables (GRADEpro GDT 2015). We justified decisions to downgrade the certainty of evidence in the footnotes.

A parallel systematic review provided the best estimates of the minimally important differences (MIDs) for each of the measures in the trials where available (Hao 2019). In pain (VAS/NRS), we considered 1.5 points (0 to 10 scale; Tashjian 2009; Hao 2019); in function (Constant score) 8.3 points (Hao 2019); on EQ‐5D‐3L index (UK version; −0.59 to 1) 0.07 (Hao 2019); and on 15D 0.015 points (Alanne 2015).

Subgroup analysis and investigation of heterogeneity

We did not plan subgroup analyses.

Sensitivity analysis

We performed sensitivity analyses to investigate the robustness of the treatment effect by performing an analysis that included all trials combined, that is, trials with placebo and exercise groups, to see if inclusion of trials that did not blind participants changed the overall treatment effect. These were performed for the outcomes of overall pain and function at the six‐month and one‐year time points.

We also planned a sensitivity analysis to assess the impact of including studies with imputed SDs for the outcomes of pain and function.

Results

Description of studies

Results of the search

Only three of the 14 trials included in the previous Cochrane Review (Coghlan 2008), met the inclusion criteria for this updated review due to the restriction in scope from the original review (Brox 1993; Haahr 2005; Rahme 1998). We excluded 11 trials because they compared one type of surgery to another. An additional trial that we had previuosly excluded due to uncertainty about its design, we have now included, following correspondence from the trial authors confirming that it was an RCT (Peters 1997).

The results of the updated search are shown in Figure 1. The updated search returned 3913 records. After duplicates were removed and the titles and abstracts screened for eligibility, we retrieved 29 full texts. Five new RCTs (Beard 2018; Farfaras 2016; Paavola 2018; Peters 1997; Ketola 2009) met the inclusion criteria for this review. In total, we included eight trials in the current review.

Figure 1
Study flow diagram

Study flow diagram

For serious adverse events, we included two studies from a single, prospective registry collecting outcomes of arthroscopic shoulder surgery including subacromial decompression (Hill 2017; Shields 2015) as identified in the co‐published review (Lähdeoja 2019).

We identified one ongoing trial meeting the inclusion criteria and its characteristics are presented in Characteristics of ongoing studies table (Paloneva 2008). One trial (TRANSIT 2006), was reported to be completed, but we could not identify published results and the trial authors did not respond to queries. This trial is awaiting classification, along with Schulze 2017, which is awaiting translation from German.

We could find no trial registration for four of the included trials (Brox 1993; Farfaras 2016; Haahr 2005; Ketola 2009), noting that one trial was published before trial registration became mandatory (Brox 1993).

Included studies

We have provided a full description of the eight included trials in the Characteristics of included studies table, and a summary of trial features and participant characteristics in Table 1.

Open in table viewer
Table 1. Baseline demographic and clinical characteristics of the trial participants

Trial

Country

Groups (number randomised)

Mean age, years

Mean symptom duration in months (duration specified in inclusion criteria)

Mean pain

Mean shoulder‐specific score

Mean HRQoL

Treatment delivered by

Beard 2018

UK

Subacromial decompression (106)

53

Not reported (≥ 3 months)

Not reported

39a

0.52

38 different surgeons

Placebo surgery (103)

54

43a

0.55

No treatment (104)

53

38a

0.50

Not specified

Brox 1993

Norway

Subacromial decompression (45)

48

Not reported (≥ 3 months)

Not reported

64b

Not measured

2 surgeons

Exercise therapy (50)

47

66

1 physiotherapist

Placebo‐laser (30)

48

65

1 physiotherapist

Farfaras 2016

Sweden

Open subacromial decompression (24)

52

Not reported (≥ 6 months)

Not reported

48a

69.6 (SF‐36 General Health)

Not specified

Arthroscopic subacromial decompression (29)

49

56a

60.1

Exercise therapy (34)

50

56a

67.3

Haahr 2005

Denmark

Subacromial decompression (45)

45

Not reported (6 months‐3 years)

5.9

35a

Not measured

2 surgeons

Exercise therapy (45)

44

6.5

34a

2 physiotherapists

Ketola 2009

Finland

Subacromial decompression (70)

46

31 (≥ 3 months)

6.5

78c

Not measured

One surgeon

Exercise therapy (70)

48

30 (≥ 3 months)

6.5

83c

Physiotherapist

Paavola 2018

Finland

Subacromial decompression (59)

51

18 (≥ 3 months)

7.1

32a

0.89 (15D)

Not specified

Placebo surgery (63)

51

18 (≥ 3 months)

7.2

32a

0.89

Exercise therapy (71)

50

22 (≥ 3 months)

7.2

35a

0.88

Peters 1997

Germany

Subacromial decompression (32)

56

Not reported (not reported)

Not measured

54d

Not measured

Not specified

Exercise therapy (40)

59

59d

Rahme 1998

Sweden

Subacromial decompression (21)

42

Not reported (≥ 12 months)

Not reported

Not measured

Not measured

Not specified

Exercise therapy (21)

42

aConstant score.
bNeer score.
cShoulder Disability Questionnaire.
dSubjective Shoulder Rating Scale.

Randomised controlled trials
Trial design, setting and characteristics

Two trials compared arthroscopic subacromial decompression surgery with arthroscopy only (placebo surgery; Beard 2018; Paavola 2018). The surgery was followed by postoperative exercises in all treatment groups. Both trials also included a third treatment group comprising no treatment (active monitoring), in Beard 2018 and an exercise therapy program in Paavola 2018.

Six trials compared arthroscopic or open subacromial decompression followed by exercises with exercises alone (Brox 1993; Farfaras 2016; Haahr 2005; Ketola 2009; Peters 1997; Rahme 1998). One of these trials, Farfaras 2016, included two surgery groups (open or arthroscopic decompression), while one other trial, Brox 1993, also included a third treatment group comprising placebo laser.

The included trials were conducted in six different countries: Denmark (Haahr 2005), Finland (Ketola 2009; Paavola 2018), Germany (Peters 1997), Norway (Brox 1993), Sweden (Farfaras 2016; Rahme 1998), and the UK (Beard 2018).

The total duration of the trials varied between 3 and 14 years and the duration of follow‐up ranged from one year (Beard 2018; Rahme 1998), up to a mean of 12‐13 years in two trials (Ketola 2009; Farfaras 2016).

Three trials reported receiving funding from foundations unrelated to commercial purposes (Beard 2018; Brox 1993; Paavola 2018). Five trials did not report funding sources (Farfaras 2016; Haahr 2005; Ketola 2009; Peters 1997; Rahme 1998). One study reported that one of its authors had received remuneration from an instrument company but the trial itself was not funded by the company (Farfaras 2016).

All studies with an exercise therapy treatment arm allowed cross‐over from exercise therapy to surgery. In the placebo‐controlled trials, the blinded participants could be unblinded if they desired other interventions due to poor outcome or were hospitalised due to a complication (Beard 2018; Paavola 2018). The number of participants not receiving their allocated treatment, having surgery although allocated to exercises, or who were unblinded during follow‐up are presented in Table 2.

Open in table viewer
Table 2. Deviations from allocated treatment

Trial

Group

Did not receive allocated treatment

Crossed over to active surgery

Re‐operated

Side interventions in surgery

Unblinded

Beard 2018

Subacromial decompression

19 (18%)

N/Aa

0

None reported

0 (0%)

Placebo surgery

35 (34%)

10 (10%)

0

None reported

1 (1%)

No treatment

26 (25%)

25 (24%)

0

No surgery

No blinding

Brox 1993

Subacromial decompression

13 (29%)

N/Aa

0

None reported

No blinding

Eexercise therapy

7 (14%)

1 (2%)

0

No surgery

Placebo‐laser

4 (13%)

2 (7%)

0

No surgery

Farfaras 2016

Open subacromial decompression

6 (25%)

N/Aa

0

None reported

No blinding

Arthroscopic subacromial decompression

5 (29%)

N/Aa

0

None reported

Exercise therapy

0

3 (9%)

0

No surgery

Haahr 2005

Subacromial decompression

4 (9%)

N/Aa

0

None reported

No blinding

Eercise therapy

2 (4%)

6 (13%) by 1 year
11 (24%) by 4‐8 years

0

No surgery

Ketola 2009

Subacromial decompression

13 (19%)

N/Aa

0

14 (20%) labrum repair

No blinding

Exercise therapy

0

5 (7%) by 1 year

14 (20%) by 2 years
18 (26%) by 5 years

0

No surgery

Paavola 2018

Subacromial decompression

0

N/Aa

2 (3%)

0 (0%)

6 (10%)

Placebo surgery

0

8 (13%)

8 (13%)

0 (0%)

9 (14%)

Exercise therapy

0

15 (21%)

3 (4%)

No surgery

No blinding

Peters 1997

Subacromial decompression

0

N/Aa

0

None reported

No blinding

Exercise therapy

0

0 (0%)

0

None reported

Rahme 1998

Subacromial decompression

0

N/Aa

0

5 rotator cuff tears were sutured

No blinding

Exercise therapy

0

13 (62%)

0

No surgery

aN/A (not applicable), participants in subacromial decompression group could not cross over to surgery.

Trial participants

All participants were recruited from secondary/tertiary care hospitals offering surgical care. Across all included trials there were a total of 1062 participants allocated to either operative or non‐operative treatments. The two placebo‐controlled trials included 506 participants; 331 were randomised to either subacromial decompression or placebo surgery and 175 were randomised to unmasked exercise or no treatment. In the open‐label trials, 376 participants were randomised to subacromial decompression (open or arthroscopic) or exercise therapy and 30 were randomised to unmasked placebo laser in one trial. The number of participants per trial ranged from 42 to 313 and their mean age varied from 42 to 65 years, and almost all had a slight female predominance (other than Peters 1997).

Inclusion criteria for all trials were comparable, requiring clinical features consistent with impingement syndrome, including painful abduction and positive impingement test. Three trials explicitly reported exclusion of full‐thickness rotator cuff tears (Beard 2018; Ketola 2009; Paavola 2018). Brox 1993 excluded "rotator cuff rupture" and Farfaras 2016 "total rotator cuff rupture"; Haahr 2005 excluded participants who had, "signs of a rupture of the cuff", and Peters 1997 excluded participants if they had, "sonographic evidence of complete rupture of the rotator cuff". One trial did not explicitly report exclusion of tears (Rahme 1998).

Two trials used MRI (Ketola 2009; Paavola 2018), two used ultrasound (Farfaras 2016; Haahr 2005), and one used MRI or ultrasound (Beard 2018), to identify rotator cuff tears. Two trials did not specify exclusion on the basis of imaging (Brox 1993; Rahme 1998). In Rahme 1998, 3 of 21(14%) participants in the surgery group were found to have full‐thickness rotator cuff tears during surgery and these were repaired. The corresponding number in the non‐operative treatment group is unknown.

Four trials required symptoms to have been present for at least three months (Beard 2018; Brox 1993; Ketola 2009; Paavola 2018), two trials required symptoms to have been present for six months (Farfaras 2016; Haahr 2005), one trial required symptoms to have been present for 12 months (Rahme 1998), and one trial did not specify a time (Peters 1997). Six trials did not report mean symptom duration, or reported it in categories, and we could not extract the mean duration (Beard 2018; Brox 1993; Farfaras 2016; Haahr 2005; Peters 1997; Rahme 1998). Mean symptom duration was 30 to 31 months across treatment groups in Ketola 2009 and 18 to 22 months across the three treatment groups in Paavola 2018.

Mean baseline pain scores were comparable across the trials, varying between 5.9 and 7.2 (0 to 10 scale). Mean baseline function measured by the Constant‐score (possible range 0 to 100, higher is better) varied between 31 and 58 in the four trials that included this measure (Beard 2018; Farfaras 2016; Haahr 2005; Paavola 2018). Ketola 2009 measured function with the SDQ (possible range 0 to 100, higher is worse), and baseline scores were 78 and 83 (reversed scores 22 and 17) in surgery and exercise groups, respectively. Brox 1993 measured function using the Neer score (possible range 0 to 100, higher is better), and the baseline scores were 64, 66 and 65 in the surgery, exercises and placebo‐laser groups, respectively.

Health‐related quality of life was assessed in three trials, all using different measures. Beard 2018 reported a baseline of 0.50 to 0.55 measured by the EQ‐5D index (possible range −0.59 to 1 scale, higher is better); Paavola 2018 reported a baseline of 0.88 to 0.89, measured by the 15D (possible range 0 to 1 scale, higher is better); and Farfaras 2016 reported all SF‐36 subdomains (possible range 0 to 1, higher score indicates lower disability), at baseline with a baseline score of 74.3 (open subacromial decompression), 65.2 (arthroscopic subacromial decompression), and 73.5 (exercise therapy), in the SF‐36 mental health score.

Paavola 2018 excluded participants if the surgeon deemed that pain was not due to impingement during arthroscopy but before participants were randomised (which occurred intra‐operatively). Beard 2018 randomised participants before the procedure and did not exclude patients if other pathologies were found at surgery. In trials comparing subacromial decompression surgery to exercise therapy, the participants in the exercise group did not undergo arthroscopy to rule out other pathologies (Brox 1993; Farfaras 2016; Haahr 2005; Ketola 2009; Peters 1997; Rahme 1998).

Interventions

Details of the interventions in each trial are presented in the Characteristics of included studies table. One to 38 surgeons performed operations, depending on the trial. The operations were performed arthroscopically in all trials except the ope‐ surgery group in Farfaras 2016 and the surgery group in Rahme 1998.

Arthroscopic subacromial decompression appeared to have been performed similarly across the studies. It included bursectomy, followed by removal of bone from the anterior/lateral undersurface of acromion and release of the acromioclavicular ligament. In Ketola 2009, the acromioclavicular ligament was released only if the operating surgeon deemed it to be tight; in this trial the surgeon also repaired labrum injuries in 14 participants. Other trials did not specifically report other surgical co‐interventions in the operative treatment groups.

Physiotherapists instructed and supervised exercises, which included home exercises. In the exercise groups, the exercises focused on active strengthening and correction of balance and humeroscapular kinematics. One trial reported specific details of the exercises (Paavola 2018).

Most of the studies did not explicitly report whether NSAIDs or glucocorticoid injections were permitted during the trial. However Ketola 2009 indicated that participants could receive up to three injections during the trial and reported a mean of 1 injection (range 1 to 10), in the exercise group and 0.3 injections (range 0 to 3), in the surgery group by two years' follow‐up. The details of the no‐treatment group in Beard 2018 and placebo‐laser group in Brox 1993 are displayed in the Characteristics of included studies table.

Outcomes

Pain

Two trials did not report a pain outcome (Farfaras 2016; Peters 1997). Five trials measured and reported pain in various continuous scales, all with higher scores indicating worse pain (Beard 2018; Brox 1993; Haahr 2005; Ketola 2009; Paavola 2018). Rahme 1998 measured pain using a continuous scale but only reported it categorically. Two trials included dichotomous assessment of pain (Ketola 2009; Paavola 2018).

Beard 2018 measured pain using the PainDETECT questionnaire, which assesses current, strongest and average pain intensity on a NRS from 0 to 10. Brox 1993 assessed pain with activity, as well as at rest and at night, on a 1 to 9 scale. Haahr 2005 measured pain using the Constant pain subscore, and also measured worst and average pain and discomfort in the last three months, and average pain and discomfort in the past seven days (all on 0 to 9 scales), using the Project on Research and Intervention in Monotonous work (PRIM) questionnaire. Ketola 2009 measured pain (unspecified) as well as pain at night on a 0 to 10 scale and also reported the proportion of pain‐free participants (VAS < 3), and pain‐free days during the last three months. Paavola 2018 measured pain at rest and with arm activity on a 0 to 100 scale and also reported the proportion of participants who exceeded the threshold for minimal clinically important improvement and the proportion who had reached the patient‐acceptable symptom state. Rahme 1998 measured pain at rest on a 0 to 10 scale but only reported the results as the proportion of participants reaching more than 50% reduction in pain.

Function

Seven trials included a composite multidimensional shoulder score, which could include pain, disability, range of motion and strength (Beard 2018; Brox 1993; Farfaras 2016; Haahr 2005; Ketola 2009; Paavola 2018; Peters 1997). These included the Constant score (Beard 2018; Farfaras 2016; Haahr 2005; Paavola 2018), Oxford Shoulder Score (Beard 2018), Simple Shoulder Test (Paavola 2018), Shoulder Disablity Questionnaire (Ketola 2009), Watson‐Sonnabend score (Farfaras 2016), and Neer score (Brox 1993). In addition, Ketola 2009 included a self‐reported assessment of function/disability measured on a VAS/NRS 0 to 10 scale, and Haahr 2005 reported 'impaired activity' (0 to 9 scale, higher is worse) as a PRIM sub score. Rahme 1998 assessed function by rating 'pour out of pot' and 'hand in neck' manoeuvres, and Peters 1997 used the subjective shoulder rating scale, a questionnaire developed and validated by the same authors (Kohn 1997).

Participant global assessment of treatment success

Five trials included varying measures of global assessment of treatment success (Beard 2018; Brox 1993; Ketola 2009; Paavola 2018; Rahme 1998).

Beard 2018 assessed global assessment of satisfaction with three questions: 1) How are the problems now compared to before randomisation? (7‐step Likert scale from no problems to much worse); 2) How pleased are you with the results of the treatment? (5‐step Likert scale from very pleased to very disappointed); and 3) Would you choose the same treatment again? (yes/no/not sure). Brox 1993 defined treatment success as those who had more than 80 out of 100 on the Neer score (but only reported this outcome for those who continued follow‐up until 2.5 years, at six months and 2.5 years). Ketola 2009 assessed proportion of participants whose overall state of health was better compared with before treatment on a 5‐point scale ranging from a lot worse to a lot better at a mean of 12 years' follow‐up. Paavola 2018 assessed global satisfaction on a VAS scale and also reported proportion of participants who were 'responders' (satisfied or very satisfied with treatment outcome used. Rahme 1998 defined success as relative reduction of pain by more than 50% compared with baseline.

Health‐related quality of life

Four trials included a measure of health‐related quality of life (Beard 2018; Farfaras 2016; Ketola 2009; Paavola 2018). Beard 2018 used the European Quality of Life with five dimensions index (EQ‐5D index) and EQ‐VAS index, Farfaras 2016 used the SF‐36, and two trials used the 15D (Ketola 2009; Paavola 2018), although Ketola 2009 only reported this outcome at more than 10 years in.

Adverse events and serious adverse events

Only three trials reported adverse events (Beard 2018; Ketola 2009; Paavola 2018). No studies reported serious adverse events.

Minor outcomes

Three trials included a measure of participation (recreation and work; Brox 1993; Ketola 2009; Paavola 2018). Paavola 2018 reported the number of participants at work and able to perform sports or leisure activities without difficulties. Brox 1993 reported the number of participants absent from work due to shoulder problems. Ketola 2009 measured self‐reported working ability on a VAS scale and sick leave due to shoulder reasons in three categories (1 to 7 days per year; 8 to 14 days per year; > 14 days per year), and whether or not the participant was retired due to shoulder condition (at a mean of 12 years' follow‐up only).

None of the trial authors included a definition of treatment failure. Ketola 2009 used MRI to identify cuff tears at five‐year follow‐up and Farfaras 2016 used ultrasound at 13 years and we considered full‐thickness tears as failures. Cross‐overs could occur in one direction (from exercise to surgery) and we did not consider these as treatment failures. The deviations from allocated treatment by trial are presented in Table 2.

Observational studies

The two included observational studies included samples from a single surgical registry in the USA over two separate time periods, using a systematic sampling process to minimise risk of selection bias, and investigating 30‐day postoperative complication rates (Hill 2017; Shields 2015). Hill 2017 included 15,015 participants undergoing arthroscopic shoulder surgery from 258 participating centres for the years 2005 to 2011, and Shields 2015 included 10,255 participants from more than 600 centres undergoing surgery from 2011 to 2013 (Table 3).

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Table 3. Types and numbers of surgical procedures included in the two registry studies

Procedure

N (%) Hill 2017

N (%) Shields 2015

Rotator cuff repair

6399 (43)

3439 (33.5)

Subacromial decompression

2542 (16.9)

3362 (32.8)

Superior labrum lesion repair

1175 (7.8)

976 (9.5)

Capsuloraphy

1000 (6.7)

726 (7)

Distal clavicle resection

1029 (6.9)

544 (5.3)

Extensive debridement

1130 (7.5)

461 (4.5)

Limited debridement

1029 (6.9)

379 (3.7)

Lysis and resection of adhesion

279 (1.9)

149 (1.5)

Biceps tenodesis

263 (1.8)

105 (1)

Synovectomy

137 (0.9)

76 (0.7)

Foreign body removal

62 (0.4)

38 (0.4)

All

15,015

10,255

Excluded studies

We excluded 14 trials from this update and specify reasons for exclusion in the Characteristics of excluded studies table. Four trials recruited mainly participants with full‐thickness rotator cuff tears or calcific tendinopathy and these trials will be included in other updates in this series of Cochrane Reviews of interventions for shoulder disorders (Kukkonen 2014; Lambers Heerspink 2015; Maugars 2009; Moosmayer 2010). In comparison to our previous version of this review (Coghlan 2008), we also excluded trials comparing one type of surgery to another from this update.

Risk of bias in included studies

The summary of the risk of bias assessment is presented in Figure 2.

Figure 2
'Risk of bias' summary: review authors' judgements about each risk of bias item for each included study

'Risk of bias' summary: review authors' judgements about each risk of bias item for each included study

Two trials comparing subacromial decompression with placebo met all methodological low risk of bias criteria for this comparison (Beard 2018; Paavola 2018). The other trials had various sources of bias, most notably detection and performance bias arising from lack of blinding of participants and personnel (Brox 1993; Farfaras 2016; Haahr 2005; Ketola 2009; Peters 1997; Rahme 1998). These same biases applied to the comparisons of surgery to no treatment (Beard 2018), or to exercises (Paavola 2018), of the placebo‐controlled trials. The assessment of each domain of risk of bias for the included trials is summarised in the Characteristics of included studies table.

Allocation

Four trials reported adequate random sequence generation and allocation concealment, and we therefore deemed them to have low risk of selection bias (Beard 2018; Haahr 2005; Ketola 2009; Paavola 2018), while we deemed a fifth trial at unclear risk due to failure to explicitly report allocation concealment, although there was likely adequate random sequence generation (Brox 1993).

We judged two trials to be at unclear risk of selection bias due to failure to adequately report their methods of randomisation and allocation concealment (Peters 1997; Rahme 1998), while we judged one at high risk for both of these domains (Farfaras 2016).

Blinding

Both placebo‐controlled trials were at low risk of performance and detection bias for the comparison of decompression and placebo surgery as they blinded participants and all study personnel other than those in the operating room (Beard 2018; Paavola 2018). For the comparison of surgery to no treatment in Beard 2018 and exercises alone in Paavola 2018, we judged there to be high risk of performance and detection bias, as the participants in the non‐operative treatment groups were not blinded. This may have resulted in an overestimate of the benefit of surgery for these comparisons.

Similarly we judged all trials that compared surgery to non‐operative treatment to be at high risk of performance and detection bias as participants were aware of their treatment allocation (Brox 1993; Farfaras 2016; Haahr 2005; Ketola 2009; Peters 1997; Rahme 1998). We assigned a high risk of bias even if trialists had blinded outcome assessors because all major outcomes were subjective. The trials did not use outcomes that were completely objective and for the imaging outcomes, the radiologists could not be reliably blinded to treatment allocation.

Incomplete outcome data

Risk of attrition bias was low in four trials (Beard 2018; Brox 1993; Haahr 2005; Paavola 2018), high in two trials (Farfaras 2016; Ketola 2009), and unclear in two trials (Peters 1997; Rahme 1998).

In Beard 2018, the number of participants and reasons for loss to follow‐up were similar across the groups (six months: 16/106 (15%) and 9/103 (9%) in the decompression and placebo surgery groups respectively; one year: 18/106 (17%) and 10/103 (10%) in the decompression and placebo surgery groups respectively). In Brox 1993, 4 out of 45 (9%) and 1 out of 50 (2%) participants were lost to follow‐up at six months in the surgery and exercise groups respectively, and the corresponding loss to follow‐up was 6 out of 45 (13%) and 5 out of 50 (10%) participants at 2.5 years. In Haahr 2005 4 out of 45 (9%) and 2 out of 45(4%) participants dropped out or were lost to follow‐up at 12 months in the surgery and exercise groups respectively. In Paavola 2018, missing data were also low and comparable between the groups: for pain and function zero to four participants in the decompression group (0% to 7%); two to seven participants (3 to 11%) in the placebo‐surgery group, and three to seven participants (4% to 10%) in the exercise therapy group in follow‐up points up to 24 months.

Risk of attrition bias was high in Farfaras 2016 as data from 9 out of 24 participants in the open decompression group, 10 out of 29 participants in the arthroscopic decompression group and 13 out of 34 participants in the exercise group were not included in the analysis (only a per‐protocol analysis was performed). Risk of attrition bias was high in Ketola 2009 as there were large and differing proportions of missing data at 3, 6 and 12 months' follow‐up (three months: 27/70 (39%) in the decompression group versus 13/70 (19%) in the exercise group; six months: 26/70 (37%) in the decompression group versus 14/70 (20%) in the exercise group; 12 months: 19/70 (27%) in the decompression group versus 18/70 (26%) in the exercise group). Risk of attrition bias was unclear in Peters 1997 as there was an imbalance in loss to follow‐up at one year (decompression: 6/32 (19%) versus 4/40 (10%) in the exercise group), and the reasons were not provided. It was also unclear in Rahme 1998 as 3 out of 21 (14%) participants in the exercise group were lost to follow‐up and no reasons were provided.

Selective reporting

Risk of reporting bias was low in two trials (Beard 2018; Paavola 2018), high in three trials (Haahr 2005; Peters 1997; Rahme 1998), and unclear in three trials (Brox 1993; Farfaras 2016; Ketola 2009).

We judged Haahr 2005 to be at high risk of reporting bias as there was no trial protocol or trial registration and some outcomes appeared to have been added post hoc and others were incompletely reported. No protocol or trial registration was available for Peters 1997 to confirm whether they had collected any measures other than the subjective shoulder rating score. Rahme 1998 did not report the outcomes specified in the methods consistently and at all time points. For example, they only reported six‐month and 12‐month results in pain but they also specified them as collected at eight and 16 weeks.

We assigned unclear risk for reporting bias for Brox 1993 mainly as participation in work was only reported at two to five years for a subset of participants. It also had no trial protocol or trial registration but this predated mandatory trial registration. We also assigned unclear risk to Farfaras 2016 as we could not find a published protocol and they did not report some outcomes pertinent to this review (pain and adverse events). We also judged Ketola 2009 to be at unclear risk of selective reporting, mainly because some outcomes reported to be measured were not reported (passive movement and strength), and they reported adverse events only for the surgery group.

Other potential sources of bias

Four trials had no other identified potential sources of bias (Beard 2018; Haahr 2005; Paavola 2018; Peters 1997).

We deemed three trials at high risk of other bias. Brox 1993 performed an unplanned interim analysis at six months after recruiting 68 out of 125 participants, and as this showed no benefit of placebo laser, they terminated planned recruitment to this group. Farfaras 2016 stopped recruitment early and there was an unexplained imbalance in the number of participants across the three treatment arms. In Rahme 1998, 12 out of 21 (57%) participants originally allocated to the exercises group crossed over to surgery after six months. The trial authors analysed them as a separate group. In our analysis, we included them in the exercise group as allocated, to conform to intention‐to‐treat principles (Analysis 2.3).

We judged Ketola 2009 to be at unclear risk of other bias as nine (13%) participants in the surgery group had an unplanned labral repair during the operation, which may have biased the estimate of the effect of surgery (in either direction). Both treatment groups also received glucocorticoid injections over the two‐year follow‐up (mean of 0.3, range 0 to 3; and 1.0, range 0 to 10 in the surgery and exercise groups, respectively). This may also have biased the estimates.

Risk of bias in the observational studies

The 'Risk of bias' assessment from the co‐published, parallel systematic review (Lähdeoja 2019), is reproduced in Table 4. In general these studies were at low risk of most biases.

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Table 4. Risk of bias for registry studies of serious adverse events

Domain

Hill 2017

Shields 2015

Judgement

Study participation

Unsure, but judged unlikely to incur significant bias

Yes, large number of centres, judged likely to be representative

Unclear

Study attrition

Probably low risk given the tracking of participants who went elsewhere for care, and given follow‐up was 30 days

Probably low risk given the tracking of participants who went elsewhere for care, and given follow‐up was 30 days

Low

Prognostic factor measurement

Yes: arthroscopic procedure is the prognostic factor

Yes: arthroscopic procedure is the prognostic factor

Low

Outcome measurement

Yes: based on hospital record + participant contact call

Yes: based on hospital record + participant contact call

Low

Study confounding

Yes: total harms are of interest, no proper confounders

Yes: total harms are of interest, no proper confounders

Low

Statistical analysis and reporting

Unclear, judged not likely to lead to overestimation of harms

Unclear, judged not likely to lead to overestimation of harms

Low

Effects of interventions

See: Summary of findings for the main comparison Subacromial decompression compared to placebo surgery; Summary of findings 2 Subacromial decompression compared to exercises

Benefits

1. Subacromial decompression versus placebo

We considered that both placebo‐controlled trials (Beard 2018; Paavola 2018) recruited clinically comparable participants with respect to inclusion criteria and baseline characteristics of pain, disability and quality of life, to allow pooling of data. We were able to pool data for pain, function (both trials used the Constant score), participant global assessment of treatment success, health‐related quality of life and adverse events. Statistical heterogeneity was unimportant across all outcomes and end points. The certainty of evidence was high for pain, function and health‐related quality of life and moderate for participant global assessment of treatment success (downgraded for imprecision; summary of findings Table for the main comparison).

Pain

Based upon the two trials, there were no clinically important differences between subacromial decompression and placebo surgery with respect to mean pain at six months or at one year (high‐certainty evidence). Pain was 4 points with placebo on a zero to 10‐point scale (lower score indicating less pain), and 0.07 points worse (95% CI 0.51 better to 0.64 worse, 299 participants), with subacromial decompression at six months, or 0.7% worse (5% better to 6% worse; Analysis 1.1; summary of findings Table for the main comparison). At one year, mean pain was 2.9 points with placebo and 0.26 points better (95% CI 0.84 better to 0.33 worse, 284 participants), with subacromial decompression, an absolute improvement of 3% (3% worse to 8% better).

Based upon one trial (Paavola 2018), at three months and two years, there were also no clinically important between‐group differences in pain with subacromial decompression versus placebo surgery but we downgraded the evidence to moderate certainty due to imprecision (one trial, 95% CI overlaps MID at two years). At three months, pain was 3.7 points with placebo and 0.47 points worse (95% CI 0.45 better to 1.39 worse, 1 trial, 117 participants), with subacromial decompression. At two years, pain was 2.5 points with placebo and 0.90 points better ( 95% CI 1.79 better to ‐0.01 worse, 118 participants), with surgery.

Function

There was no evidence of clinically important between‐group differences with respect to mean function at any time point (2 trials at 6 months and 1 year and 1 trial at 2 years). Mean function on a zero to 100 scale (higher indicates better function), was 61 points with placebo and 3.7 points worse (95% CI 8.7 worse to 1.3 better, 286 participants) with subacromial decompression at six months; 69 points with placebo and 2.8 points better (95% CI 1.4 worse to 6.9 better, 274 participants) with subacromial decompression at 1‐2 years; and 74 points with placebo and 4.2 points better (95% CI 1.61 worse to 10.01 better), with subacromial decompression at two years (Analysis 1.2). At two years, the 95% CIs do not exclude a clinically important difference.

Participant global assessment of treatment success

Based upon moderate‐certainty evidence (downgraded for imprecision), from two trials, we found no evidence of clinically important between‐group differences in the proportion of participants who rated treatment as successful at six months (surgery: 82/143 (57%) versus placebo: 72/150 (48%), RR 1.17, 95% CI 0.89 to 1.54) or at one year (surgery: 101/142 (71%) versus placebo: 97/148 (66%); RR 1.08, 95% CI 0.93 to 1.27; Analysis 1.3). Based on a single study (Paavola 2018), the success rates were also comparable at two years (surgery: 46/58 (79%) versus placebo 47/58 (81%), RR 0.98, 95% CI 0.82 to 1.17).

Health‐related quality of life

We pooled EQ‐5D data from Beard 2018 with 15D data from Paavola 2018 at six months and one year.

Based upon two trials, subacromial decompression did not improve quality of life more than placebo at six months (SMD ‐0.05 (95% CI ‐0.27 to 0.18, 292 participants). When this is back‐transformed, the EQ‐5D index was 0.67 with placebo and 0.01 points worse (0.08 worse to 0.05 better, 292 participants), with subacromial decompression. At one year the SMD was ‐0.09 (95% CI ‐0.39 to 0.21, 285 participants), and back‐transformed to the EQ‐5D index, EQ‐5D was 0.73 with placebo and 0.03 points worse (95% CI 0.11 worse to 0.06 better; 285 participants), with subacromial decompression (Analysis 1.4).

Based upon one trial there was also no between‐group clinically important difference (downgraded to moderate certainty due to imprecision), in health‐related quality of life at three months. 15D was 0.92 with placebo and 0.01 worse (95% CI 0.03 worse to 0.01 better; 118 participants), with subacromial decompression. At two years, 15D was 0.92 with placebo and 0 points (95% CI 0.01 worse to 0.01 better, 118 participants) better with subacromial decompression (high‐certainty evidence).

Minor outcomes

Based upon one trial (Paavola 2018), there were no important differences in participation in work or return to sport or leisure activities up to two years (Analysis 1.5; Analysis 1.6).

2. Subacromial decompression versus exercise therapy

Of the seven trials that compared subacromial decompression followed by exercises to exercises alone (Brox 1993, Farfaras 2016, Haahr 2005, Ketola 2009; Paavola 2018; Peters 1997; Rahme 1998), we were able to pool outcome data from one or more of the seven trials across the outcomes of interest. The trials recruited clinically similar participants except that three out of 21 (14%) participants in the decompression group in Rahme 1998 were identified as having full‐thickness rotator cuff tears during surgery and the number in the exercise group is unknown.

Pain

Four trials reported pain at three and six months (Brox 1993; Haahr 2005; Ketola 2009; Paavola 2018); three trials at one year (Haahr 2005; Ketola 2009; Paavola 2018), and at two years (Brox 1993; Ketola 2009; Paavola 2018); two trials at five years (Haahr 2005; Ketola 2009), and one trial at ten years (Ketola 2009). Statistical heterogeneity was unimportant at all time points except at two (I2 = 63%), and five years (I2 = 73%).

Moderate‐certainty evidence (downgraded due to the risk of detection and performance bias), indicates that pain did not differ between surgery and exercises at three months, six months or two years. At three months, pain was 4.4 with exercise and 0.55 better (95% CI 1.24 better to 0.14 worse, 361 participants); at six months, 3.9 with exercise and 0.56 points better (95% CI 0.02 better to 1.09 better, 399 participants) with surgery; at two years, 2.8 points after exercise and 0.44 points better (95% CI 0.49 worse to 1.37 better, 352 participants; Analysis 2.1).

At one year, the evidence was low certainty due to bias and imprecision. The 95% CIs included a clinically important change in favour of surgery: pain was 3.7 with exercise and 1.01 points better (95% CI 0.42 better to 1.60 better, 316 participants) with surgery.

At five and ten years, we downgraded the evidence once for bias to moderate certainty; the 95% CIs exclude a clinically important benefit with surgery. At five years, pain was 2.7 with exercise and 0.36 points worse (95% CI 1.17 better to 1.89 worse, 188 participants) with surgery; at ten years, pain was 1.8 with exercises and 1.0 point worse (95% CI 0.25 better to 2.25 worse, 90 participants) with surgery.

Function

Three trials reported function at three months (Brox 1993; Haahr 2005; Ketola 2009); four trials at six months (Brox 1993; Haahr 2005; Ketola 2009; Paavola 2018); three trials at one year ( Haahr 2005; Ketola 2009; Peters 1997); five trials at two years (Brox 1993; Farfaras 2016; Ketola 2009; Paavola 2018; Peters 1997), three trials at five years (Haahr 2005; Ketola 2009; Peters 1997), and two trials at 10 years (Farfaras 2016; Ketola 2009).

Statistical heterogeneity ranged from I2 = 0% to I2 = 81% across different time points, but as there were only few studies this has to be interpreted with care. At six months and one year, the heterogeneity seemed to be largely driven by Ketola 2009; the outcome appears to favour surgery but the confidence intervals overlap with the other studies.

Surgery did not appear to improve function more than exercise at any time point up to five years, but the evidence was low certainty due to bias and imprecision. The 95% CIs include both no change and a clinically important change in favour of surgery. At three months, the mean function was 55 points (on a 0 to 100 scale, higher indicates better function), with exercise and 6.1 points better (95% CI 5.57 worse to 17.79 better, 257 participants), with surgery; at six months mean function was 57 points with exercise and 3.7 points better (95% CI 2.25 worse to 9.58 better, 398 participants), with surgery; at one year, mean function was 58 with exercise and 3.2 points better (95% CI 8.08 worse to 14.55 better, 259 participants), with surgery; at two years mean function was 71 with exercise and 4.9 points better, (95% CI 0.77 better to 9.11 better, 467 participants), with surgery; and at five years, function was 76 with exercise and 7.6 points better (95% CI 0.17 better to 15.09 better, 157 participants) with surgery. At 10 years, there was low‐certainty evidence (downgraded due to bias and imprecision), that surgery was better than exercise with respect to mean function; it was 69 with exercise and 9.54 points better (95% CI 1.93 better to 17.15 better, 156 participants) with surgery (Analysis 2.2).

Using SMD and back‐transformation to Constant score (0 to 100) in analysis yielded generally narrower CIs (data not shown in tables or forest plots). At three months: MD 4.2 points (95% CI −4.2 to 12.6); at six months: MD 3 points (95% CI −1.3 to 7.2); at one year: MD 1.6 points (95% CI −5.8 to 9.0); at two years: MD 4.2 points (95% CI 1.1 to 7.4); at five years: MD 4.6 points (95% CI −0.48 to 9.6); at 10 years: MD 5.8 points (95% CI −2.7 to 14.2).

Participant global assessment of treatment success

Paavola 2018 and Rahme 1998 reported global assessment of success at six months and one year, Paavola 2018 reported this outcome at two years, Haahr 2005 at five years and Ketola 2009 at 10 years. The statistical heterogeneity was unimportant (I2 = 29% at six months and I2 = 0% at one year).

In the secondary comparison we downgraded this outcome to low certainty due to bias and low event rates (imprecision). The success rates were: 40 out of 77 (52%) with surgery versus 33 out of 84 (39%) with exercises (RR 1.47, 95% CI 0.74 to 2.91), at six months; 55 out of 76 (72%) with surgery versus 49 out of 82 (60%) with exercises (RR 1.21, 95% CI 0.96 to 1.51), at one year; 46 out of 58 (79%) with surgery and 43 out of 68 (63%) with exercises (RR 1.25, 95% CI 1.00 to 1.57), at two years; 23 out of 39 (59%) for surgery and 27 out of 40 (68%) for exercises (RR 0.87, 95% CI 0.62 to 1.23), at five years; 23 out of 44 (52%) with surgery and 24 out of 46 (52%) with exercises (RR 1.00, 95% CI 0.67 to 1.49), at 10 years (Analysis 2.3).

Health‐related quality of life

Paavola 2018 measured quality of life with the 15D (0 to 1) at three months, six months, one year and two years. Farfaras 2016 measured it with the SF‐36 (0 to 100) at two years and at 10 years; and Ketola 2009 measured it with 15D at 10 years. The statistical heterogeneity was unimportant at two years (I2 = 22%) and there was no heterogeneity at 10 years.

Surgery appeared to improve health‐related quality of life more than exercise at some time points (six months and 10 years), but the evidence was low certainty due to bias and imprecision. At six months, mean quality of life was 0.89 with exercise and 0.02 points better (95% CI 0.01 better to 0.03 better, 119 participants), with surgery; at one year, mean quality of life was 0.91 with exercise and 0.01 points better (95% CI 0.01 better to 0.03 better, 116 participants) with surgery; at five years, mean quality of life was 0.92 with exercises and 0.01 points better (95% CI 0.02 worse to 0.04 better, 86 participants). At 10 years, SMD was 0.30 (95% CI −0.01 to 0.62, 155 participants). Back‐transformed to 15D, the mean quality of life was 0.89 with exercise and 0.02 points better (95% CI 0 better to 0.04 better) with surgery (Farfaras 2016; Ketola 2009; Analysis 2.4).

In other time points, we found no clinically important between‐group differences (low‐certainty evidence, downgraded due to bias and imprecision). At three months, mean quality of life was 0.9 with exercises and 0.01 points better (95% CI 0.02 worse to 0.04 better; 119 participants) with surgery; at two years, SMD was 0.13, (95% CI ‐0.22 to 0.48, 118 participants; Farfaras 2016; Paavola 2018). When back‐transformed to15D, the mean quality of life was 0.91 with exercises and 0.01 points better (0.01 worse to 0.03 better), with surgery. At five years, mean quality of life was 0.92 with exercises and 0.01 points better (95% CI 0.02 worse to 0.04 better, 86 participants). The 95% CIs do not exclude a clinically important benefit of surgery at these time points.

Minor outcomes

Brox 1993 and Paavola 2018 reported participation in work at six months' and two years' follow‐up. Paavola 2018 also reported this outcome at three months and one year, and Haahr 2005 at four to eight years' follow‐up. Ketola 2009 reported number of participants who retired for shoulder‐related reasons at five and 10 years. The statistical heterogeneity was substantial (I2 = 60%) at six months and unimportant (I2=0%) at two years. We downgraded the evidence to moderate certainty at six months and one year ( due to serious imprecision). At other time points, we downgraded the evidence to low (twice for very serious imprecision)

We found no important between‐group differences in participation in work. At three months, 39 out of 59 participants in the surgery group and 47 out of 68 in the exercise group were at work (RR 0.96, 95% CI 0.75 to 1.22); at six months, 67 out of 87 participants in surgery group and 73 out of 100 in exercise group (RR 1.05, 95% CI 0.81 to 1.36), were at work; at one year, 48 out of 56 in surgery group and 55 out of 63 were at work (RR 0.98, 95% CI 0.85 to 1.13); at two years, 67 out of 90 in surgery group versus 80 out of 93 in the exercise group (RR 0.87; 95% CI 0.70 to 1.07; Analysis 2.5). At five years 72 out of 96 (75%) participants in the surgery group and 62 out of 92 (67%) participants in the exercise group were working (RR 1.13, 95% CI 0.97 to 1.32). At 10 years, 43 out of 44 (98%) and 42 out of 46 (91%) participants were at work in the surgery group and exercise group respectively (RR 1.07, 95% CI 0.97 to 1.18).

One trial reported participation in recreational activities (Paavola 2018). There was no important differences between the groups. The participation rate was 31 out of 55 participants for surgery group versus 28 out of 65 in the exercise group (RR 1.31, 95% CI 0.91 to 1.88), at three months; 34 out of 54 for surgery versus 35 out of 62 for exercises (RR 1.12, 95% CI 0.83 to 1.50), at six months; 42 out of 54 for surgery versus 46 out of 64 for exercises (RR 1.08, 95% CI 0.88 to 1.33), at one year; and 46 out of 56 for surgery versus 48 out of 62 (RR 1.06, 95% CI 0.88 to 1.27), at two years (Analysis 2.6).

Two trials performed imaging to identify rotator cuff tears during follow‐up, one at five years (Ketola 2009), and the other at a mean of 13 years (Farfaras 2016). Full‐thickness tears in the supraspinatus tendon were identified in 8 out of 48 (17%) participants in the surgery group versus 7 out of 42 (17%) in the exercise group in Ketola 2009 (RR 1.00, 95% CI 0.40 to 2.52), at five years, and 2 out of 38 (5%) participants in the surgery group versus 4 out of 28 (14%) participants in the exercise group in Farfaras 2016 (RR 0.37, 95% CI 0.07 to 1.87), at 13 years (Analysis 2.7).

3. Subacromial decompression versus no treatment

One trial included a control group that did not receive any active intervention (active monitoring; Beard 2018). The evidence was downgraded to low certainty due to bias and imprecision (95% CI overlaps minimal important difference) for all outcomes.

Pain

At six months, mean pain was 5 points (on a zero to 10 scale), with no treatment and 0.80 points better (95% CI 0.00 better to 1.60 better; 177 participants), with surgery. At one year,the mean pain was 4.1 points with no treatment and 1.20 points better (0.36 better to 2.04 better; 166 participants), with surgery. The CIs do not exclude a clinically important difference between the groups (Analysis 3.1).

Function

At six months, mean function was 45.4 points (on a zero to 100 scale), with no treatment and 11.10 points better (95% CI 4.52 better to 17.68 better, 165 participants), with surgery. At one year, mean function was 57 points with no treatment and 9.5 points better (95% CI 2.66 better to 16.34 better, 146 participants), with surgery (Analysis 3.2). The CIs do not exclude a clinically important difference between the groups.

Global assessment of success

More participants had treatment success after surgery compared with no treatment: 49 out of 87 (56%) participants with surgery versus 27 out of 80 (34%) participants with no treatment (RR 1.67, 95% CI 1.17 to 2.39), at six months, and 62 out of 87 (71%) participants with surgery versus 43 out of 80 (54%) participants with no treatment (RR 1.33, 95% CI 1.04 to 1.69). The differences correspond with a NNTB of 4 at six months and 6 at one year (Analysis 3.3).

Health‐related quality of life

We found no clinically important difference in quality of life between surgery and no treatment but the 95% CIs do not exclude important difference. At six months, quality of life measured with the EQ‐5D index was 0.52 (−0.59 to 1 scale), with no treatment and 0.13 points better (95% CI 0.03 better to 0.23 better), with surgery. At one year, EQ‐5D was 0.66 with no treatment and 0.08 points better (95% CI 0.01 worse to 0.17 better), with surgery (Analysis 3.4).

Minor outcomes

Beard 2018 did not report any participation or treatment failure outcomes.

Harms

Subacromial decompression versus non‐operative control
Adverse events

Adverse events were reported in two randomised controlled trials (Beard 2018; Paavola 2018). Both trials included a placebo control group and also included a third treatment group comprising no treatment (active monitoring) in Beard 2018 and an exercise therapy program in Paavola 2018. A third trial (Ketola 2009) reported an absence of adverse events in the surgery group but did not explicitly report whether or not there were adverse events in the exercise therapy group. Evidence from the randomised trials was downgraded to moderate‐certainty due to imprecision from low event rates (summary of findings Table for the main comparison; summary of findings Table 2).

Beard 2018 reported that two out of 106 participants in the decompression group, two out of 103 in the placebo group and two out of 104 in the no treatment group had frozen shoulder. Paavola 2018 reported frozen shoulder in three out of 59 participants in the subacromial decompression group, one out of 63 participants in the placebo group and two out of 71 participants in the exercise group. One participant in the placebo group had temporary swelling in the brachial area related to a brachial plexus block, while one participant in the exercise group also developed aggravation of low back pain. The RR for adverse events was 0.91 (95% CI 0.31 to 2.65; 406 participants) (Analysis 4.1).

Serious adverse events

There were no reports of serious adverse events in any randomised trials. Reports of serious adverse events came from two observational reports from a surgery registry recording 30‐day morbidity after shoulder arthroscopic surgery. Overall, we are uncertain if there is an increased risk of serious adverse events with decompression surgery (moderate‐certainty evidence, downgraded for indirectness as observational studies included other arthroscopic shoulder surgeries in addition to subacromial decompression procedures).

The incidence of serious harms following mixed shoulder arthroscopic procedures was 0.5% (0.4% to 0.7%) during 2006 to 2011 (Shields 2015), and 0.6% (0.5% to 0.7%), during 2011 to 2013 (Hill 2017). The adverse events were not reported separately by procedure (Table 5). The co‐published parallel review provides the full report of these events (Lähdeoja 2019).

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Table 5. Serious adverse events in registry studies

Eventa

N (%) Hill 2017

N (%) Shields 2015

Mortality

2 (0.01)

4 (0.04)

Bleeding requiring transfusion

7 (0.05

5 (0.05)

Sepsis

0 (0)

1 (0.01)

Septic shock

3 (0.02)

2 (0.02)

Deep infection

1 (0.01)

1 (0.01)

Organ or space surgical site infection

3 (0.02)

2 (0.02)

Wound dehiscence

1 (0.01)

1 (0.01)

Deep vein thrombosis

21 (0.14)

8 (0.08)

Pulmonary embolism

20 (0.13)

7 (0.07)

Myocardial infarction

3 (0.02)

4 (0.04)

Cardiac arrest requiring cardiopulmonary

resuscitation

1 (0.01)

2 (0.02)

Cerebral vascular event

4 (0.03)

2 (0.02)

Acute renal failure

2 (0.01)

1 (0.01)

Pneumonia

13 (0.09)

7 (0.07)

Unplanned intubation

7 (0.05)

3 (0.03)

Ventilator > 48 hours

2 (0.01)

1 (0.01)

Peripheral nerve injury

2 (0.01)

2 (0.02)

aThese serious adverse events were recorded across all procedures in the registry and were not reported separately by procedure.

Sensitivity analyses

To assess the robustness of the findings in our primary analysis, we pooled data from both the placebo‐controlled trials and open‐label trials (subacromial decompression versus exercises), in sensitivity analyses. We did the analyses for pain at the six‐month and one‐year time points and for function at six‐month and one‐to‐three‐year time points.

Pooling the unblinded trials with the placebo‐controlled trials did not change the estimates of treatment effects to a clinically important level. Statistical heterogeneity was unimportant (0%) in all pain comparisons. With respect to function, statistical heterogeneity was larger when combining open‐label trials compared with the placebo‐controlled trials (I2 = 0% combining the two placebo‐controlled trials versus I2 = 50% to 63% when combining the open‐label trials).

At six months the mean pain was 3.9 (0 to 10 scale, higher is worse), with exercise or placebo and 0.31 points better (95% CI 0.12 worse to 0.75 better, 639 participants), with surgery; at one year, the mean pain was 3.3 with exercise or placebo and 0.58 points better (95% CI 0.12 better to 1.05 better, 532 participants), with surgery. The CIs exclude the clinically important difference (Analysis 5.1; Analysis 5.2).

At six months, mean function was 58 points (0 to 100 scale, higher indicates better), with exercise or placebo and 1.05 points better (95% CI 3.77 worse to 5.87 better, 625 participants), with surgery; at one to three years, mean function was 68 points with exercise or placebo and 3.2 points better (95% CI −0.81 to 7.23, 737 participants), with surgery. The CIs exclude an important difference at both time points (Analysis 5.3; Analysis 5.4).

Removing data with imputed SD for function (Peters 1997), in the decompression surgery versus exercises comparisons where relevant, resulted in wider CIs but no clinically important change in the estimate (one year: MD 3.24, 95% CI −8.08 to 14.55, including data from Peters 1997, versus MD 5.98, 95% CI −14.59 to 26.55, excluding these data; two years: MD 4.94, 95% CI 0.77 to 9.11, including data from Peters 1997, versus MD 5.07, 95% CI −0.55 to 10.70, excluding these data; five years: MD 7.63, 95% CI 0.17 to 15.09, including data from Peters 1997, versus MD 5.30, 95% CI −5.31 to 15.91 excluding these data.

Discussion

available in

Summary of main results

Two trials compared arthroscopic decompression surgery with placebo surgery (arthroscopy without decompression). Compared with placebo surgery, high‐certainty evidence indicates that subacromial decompression provides no clinically important benefits with respect to pain, function, or quality of life at one year. There was probably no important difference in participant global assessment of treatment success (moderate‐certainty evidence, downgraded for imprecision) (summary of findings Table for the main comparison). Sensitivity analyses including results from open‐label trials (with high risk of bias) did not change the estimates considerably.

Seven trials compared subacromial decompression with exercise therapy. Low‐certainty evidence available from three trials at one year indicates that there were no clinically important benefits in terms of pain, function, global assessment of success or health‐related quality of life (summary of findings Table 2). We downgraded the evidence due to bias and imprecision. Trials were subject to performance and detection biases because the participants were aware of which treatment they received. The 95% CIs around the treatment estimates do not exclude clinically important differences between exercise and surgery.

Approximately three percent of trial participants report adverse events across the randomised controlled trials, although due to low event rates, we are uncertain if surgery is associated with increased risk in adverse events compared to control groups (summary of findings Table for the main comparison).

Serious adverse events including death, deep venous thrombosis, pneumonia, and peripheral nerve damage have been observed in a surgery registry recording 30‐day morbidity after shoulder arthroscopic surgery. Although the precise estimates are unknown, based on National Surgical Quality Improvement Program (NSQIP) registry, the risk of serious adverse events is likely less than 1%

Overall completeness and applicability of evidence

This review included two placebo‐controlled trials of subacromial decompression at low risk of bias. Both trials also included a third control group of either no treatment or exercises, and participants in these groups were aware of their treatment allocation. We included an additional six trials comparing subacromial decompression to exercise therapy and these were all at high risk of performance and detection bias. One of these trials also included an additional control group that received detuned (placebo) laser treatment. We did not identify any trials comparing subacromial decompression surgery to other non‐operative treatments such as NSAIDs, or glucocorticoid or other injections.

Trials were conducted in six countries and trial participants had typical clinical features of rotator cuff disease (with impingement and without full‐thickness or complete rotator cuff tears or calcification). Most trials excluded full‐thickness tears by MRI, ultrasound or arthroscopy before inclusion. Participants were also similar in terms of age (mean age 41 to 59 years), gender distribution (slight female predominance), baseline pain and function, duration of symptoms, and failure to improve with conservative treatment (exercise therapy with or without glucocorticoid injections) for at least three months. Thus, the synthesis of this review can be applied to similar patients in clinical practice. The trials did not include elderly participants nor report outcomes in specific subpopulations such as manual workers, therefore we cannot draw any conclusion specific to these subgroups.

Our primary analysis only included the trials at low risk for bias but the results did not change significantly when all available trials were pooled together in sensitivity analysis. Placebo control introduces indirectness because placebo surgery is not a treatment option in clinical practice. However, the largely consistent findings of the unblinded studies leave little doubt of the inference that subacromial decompression provides no important benefit in people with rotator cuff disease manifesting as painful shoulder impingement.

Measurement of pain varied across trials from unspecified pain to pain with activity or average pain, as well a pain at night and at rest. We preferred to extract overall pain data when available, but some trials only reported pain with activity and others did not specify the framing of the question by which they assessed pain.

Regarding function, the trials used different outcome measures. We chose to extract Constant score whenever it was used because it was used by both trials in our primary comparison and by most of the trials in our second comparison (Beard 2018; Farfaras 2016; Haahr 2005; Paavola 2018). Other measures were not used in more than one study. Constant score puts considerable weight on capacity rather than function/disability. However, its validity and responsiveness is acceptable compared to other instruments (Roy 2010), and the parallel systematic review (Lähdeoja 2019) provided high credibility MID estimates (Hao 2019).

Since we expected the trials to provide insufficient data to estimate serious adverse events due to their low incidence, we also performed a separate review of observational studies of subacromial decompression and shoulder arthroscopy for various diagnoses as described in Lähdeoja 2019. The estimates were based on two studies using a large registry with total of 25,270 arthroscopic shoulder procedures in more than 600 centres in the USA.

The follow‐up times across trials varied from one year up to 13 years and most trials reported results after two years or more. There was increased attrition and reporting bias at the longer follow‐up time points. The five‐ and 10‐year comparisons provided low certainty evidence that surgery may improve function but not pain. However, it is possible that other factors confound the treatment effects over longer periods of follow‐up. Paavola 2018 will report five‐year results and that will likely affect our confidence in the estimates at five years.

Quality of the evidence

High certainty evidence from randomised controlled trials shows that subacromial decompression does not provide clinically important benefits over placebo in pain, function or quality of life. Due to imprecision, we downgraded evidence to moderate certainty for global assessment of treatment success; there was probably no important benefit in this outcome over placebo.

We downgraded evidence from randomised trials comparing subacromial decompression with exercise to low certainty for pain, function, global assessment of success and health‐related quality of life, primarily due to detection bias associated with the open‐label design and imprecision; the 95% CIs around the effect estimates did not rule in or out clinically important effects.

For adverse events, evidence from the randomised controlled trials was downgraded to moderate certainty due to low reported event rates, and thus imprecise estimates of the comparative risks.

As there were only a few trials in each comparison, we could not get precise estimates for heterogeneity. The two placebo‐controlled trials reported consistent results for all outcomes. Although the trials comparing subacromial decompression with exercise displayed inconsistency at six months and one year, driven by one study for function, we did not downgrade the evidence, as the CIs overlap with the other studies and there were only three to four trials in the time points that we could pool.

The evidence regarding incidence of serious adverse events was moderate certainty. The registry studies were well designed. Although a few events may occur in this population even without surgery, most observed serious adverse events were likely attributable to the index procedure (Table 4; Table 5), thus the default certainty of evidence started at high. The operations included mixed arthroscopic shoulder procedures, thus we downgraded due to indirectness.

Potential biases in the review process

To the best of our knowledge, we identified all relevant trials meeting our inclusion criteria through searching all major databases without language restrictions. We used up to three independent assessors for article screening, selection and for risk of bias judgement. None of the review authors has been involved with the conduct of the included trials.

There were too few studies to formally assess the presence of publication bias. We identified one ongoing trial comparing surgery to exercise and one trial completed in 2008 with no results available (surgery versus usual care). It is unlikely that results of these trials, if or when available, will alter the conclusions of this review.

Agreements and disagreements with other studies or reviews

In addition to our original Cochrane Review (Coghlan 2008), we identified two other published systematic reviews specifically comparing surgery with exercises in the treatment of impingement syndrome (Saltychev 2015; Toliopoulos 2014). The conclusions in these reviews are in keeping with our updated review. Both concluded that there is no benefit of surgery over conservative treatments for shoulder impingement. None of the previous reviews included placebo‐controlled trials.

Study flow diagram
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Figure 1

Study flow diagram

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'Risk of bias' summary: review authors' judgements about each risk of bias item for each included study
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Figure 2

'Risk of bias' summary: review authors' judgements about each risk of bias item for each included study

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Comparison 1 Subacromial decompression vs placebo for rotator cuff disease, Outcome 1 Pain (VAS or NRS 0‐10, lower is better).
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Analysis 1.1

Comparison 1 Subacromial decompression vs placebo for rotator cuff disease, Outcome 1 Pain (VAS or NRS 0‐10, lower is better).

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Comparison 1 Subacromial decompression vs placebo for rotator cuff disease, Outcome 2 Functional outcome (Constant score 0‐100, 100 is best).
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Analysis 1.2

Comparison 1 Subacromial decompression vs placebo for rotator cuff disease, Outcome 2 Functional outcome (Constant score 0‐100, 100 is best).

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Comparison 1 Subacromial decompression vs placebo for rotator cuff disease, Outcome 3 Global assessment of treatment success.
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Analysis 1.3

Comparison 1 Subacromial decompression vs placebo for rotator cuff disease, Outcome 3 Global assessment of treatment success.

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Comparison 1 Subacromial decompression vs placebo for rotator cuff disease, Outcome 4 Health‐related quality of life (various measures, higher is better).
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Analysis 1.4

Comparison 1 Subacromial decompression vs placebo for rotator cuff disease, Outcome 4 Health‐related quality of life (various measures, higher is better).

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Comparison 1 Subacromial decompression vs placebo for rotator cuff disease, Outcome 5 Participation (number at work).
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Analysis 1.5

Comparison 1 Subacromial decompression vs placebo for rotator cuff disease, Outcome 5 Participation (number at work).

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Comparison 1 Subacromial decompression vs placebo for rotator cuff disease, Outcome 6 Participation (number returning to sport or leisure activities).
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Analysis 1.6

Comparison 1 Subacromial decompression vs placebo for rotator cuff disease, Outcome 6 Participation (number returning to sport or leisure activities).

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Comparison 2 Subacromial decompression vs exercise treatment for rotator cuff disease, Outcome 1 Pain (VAS 0‐10, 0 is no pain).
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Analysis 2.1

Comparison 2 Subacromial decompression vs exercise treatment for rotator cuff disease, Outcome 1 Pain (VAS 0‐10, 0 is no pain).

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Comparison 2 Subacromial decompression vs exercise treatment for rotator cuff disease, Outcome 2 Functional outcome (0‐100, 100 is best).
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Analysis 2.2

Comparison 2 Subacromial decompression vs exercise treatment for rotator cuff disease, Outcome 2 Functional outcome (0‐100, 100 is best).

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Comparison 2 Subacromial decompression vs exercise treatment for rotator cuff disease, Outcome 3 Global assessment of treatment success.
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Analysis 2.3

Comparison 2 Subacromial decompression vs exercise treatment for rotator cuff disease, Outcome 3 Global assessment of treatment success.

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Comparison 2 Subacromial decompression vs exercise treatment for rotator cuff disease, Outcome 4 Health‐related quality of life (various measures, 0‐1; higher is better).
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Analysis 2.4

Comparison 2 Subacromial decompression vs exercise treatment for rotator cuff disease, Outcome 4 Health‐related quality of life (various measures, 0‐1; higher is better).

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Comparison 2 Subacromial decompression vs exercise treatment for rotator cuff disease, Outcome 5 Participation (number at work).
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Analysis 2.5

Comparison 2 Subacromial decompression vs exercise treatment for rotator cuff disease, Outcome 5 Participation (number at work).

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Comparison 2 Subacromial decompression vs exercise treatment for rotator cuff disease, Outcome 6 Participation (numbers returning to sport or leisure activities).
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Analysis 2.6

Comparison 2 Subacromial decompression vs exercise treatment for rotator cuff disease, Outcome 6 Participation (numbers returning to sport or leisure activities).

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Comparison 2 Subacromial decompression vs exercise treatment for rotator cuff disease, Outcome 7 Treatment failure.
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Analysis 2.7

Comparison 2 Subacromial decompression vs exercise treatment for rotator cuff disease, Outcome 7 Treatment failure.

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Comparison 3 Subacromial decompression vs no treatment for rotator cuff disease, Outcome 1 Pain (NRS 0‐10 lower is better).
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Analysis 3.1

Comparison 3 Subacromial decompression vs no treatment for rotator cuff disease, Outcome 1 Pain (NRS 0‐10 lower is better).

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Comparison 3 Subacromial decompression vs no treatment for rotator cuff disease, Outcome 2 Functional outcomes (Constant score 0‐100, 100 is best).
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Analysis 3.2

Comparison 3 Subacromial decompression vs no treatment for rotator cuff disease, Outcome 2 Functional outcomes (Constant score 0‐100, 100 is best).

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Comparison 3 Subacromial decompression vs no treatment for rotator cuff disease, Outcome 3 Global assessment of treatment success.
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Analysis 3.3

Comparison 3 Subacromial decompression vs no treatment for rotator cuff disease, Outcome 3 Global assessment of treatment success.

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Comparison 3 Subacromial decompression vs no treatment for rotator cuff disease, Outcome 4 Health‐related quality of life (EQ‐5D 3L −0.59 to 1, higher is better).
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Analysis 3.4

Comparison 3 Subacromial decompression vs no treatment for rotator cuff disease, Outcome 4 Health‐related quality of life (EQ‐5D 3L −0.59 to 1, higher is better).

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Comparison 4 Harms: Subacromial decompression versus non‐operative treatment, Outcome 1 Total adverse events.
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Analysis 4.1

Comparison 4 Harms: Subacromial decompression versus non‐operative treatment, Outcome 1 Total adverse events.

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Comparison 5 Sensitivity analysis (subacromial decompression vs exercises or placebo for rotator cuff disease), Outcome 1 Pain at 6 months (VAS or NRS 0‐10, higher is better).
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Analysis 5.1

Comparison 5 Sensitivity analysis (subacromial decompression vs exercises or placebo for rotator cuff disease), Outcome 1 Pain at 6 months (VAS or NRS 0‐10, higher is better).

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Comparison 5 Sensitivity analysis (subacromial decompression vs exercises or placebo for rotator cuff disease), Outcome 2 Pain at 1 year (VAS or NRS 0‐10, higher is better).
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Analysis 5.2

Comparison 5 Sensitivity analysis (subacromial decompression vs exercises or placebo for rotator cuff disease), Outcome 2 Pain at 1 year (VAS or NRS 0‐10, higher is better).

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Comparison 5 Sensitivity analysis (subacromial decompression vs exercises or placebo for rotator cuff disease), Outcome 3 Function at 6 months (various measures 0‐100, higher is better).
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Analysis 5.3

Comparison 5 Sensitivity analysis (subacromial decompression vs exercises or placebo for rotator cuff disease), Outcome 3 Function at 6 months (various measures 0‐100, higher is better).

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Comparison 5 Sensitivity analysis (subacromial decompression vs exercises or placebo for rotator cuff disease), Outcome 4 Function at 1‐3 years (various measures, higher is better).
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Analysis 5.4

Comparison 5 Sensitivity analysis (subacromial decompression vs exercises or placebo for rotator cuff disease), Outcome 4 Function at 1‐3 years (various measures, higher is better).

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Comparison 5 Sensitivity analysis (subacromial decompression vs exercises or placebo for rotator cuff disease), Outcome 5 Pain at 1 year.
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Analysis 5.5

Comparison 5 Sensitivity analysis (subacromial decompression vs exercises or placebo for rotator cuff disease), Outcome 5 Pain at 1 year.

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Summary of findings for the main comparison. Subacromial decompression compared to placebo surgery

Subacromial decompression compared to placebo surgery for people with impingement syndrome without full‐thickness rotator cuff tears

Patient or population: people with impingement syndrome without full‐thickness rotator cuff tears
Setting: hospitals in Finland and UK
Intervention: subacromial decompression
Comparison: placebo surgery (diagnostic arthroscopy)

Outcomes

Anticipated absolute effects* (95% CI)

Relative effect
(95% CI)

№ of participants
(studies)

Certainty of the evidence
(GRADE)

Comments

Risk with placebo surgery

Risk with subacromial decompression

Paina
(scale from 0‐10, 0 is no pain)
Follow‐up: 1 year

The mean pain was 2.9 pointsb

The mean pain was 0.26 points better
(0.84 better to 0.33 worse)

‐

284
(2 RCTs)

⊕⊕⊕⊕
High

Absolute difference 3% better (8% better to 3% worse); relative difference 4% better (12% better to 5% worse)c

Functional outcome

(Constant score from 0‐100, 100 is best)
Follow‐up: 1 year

The mean functional outcome was 69b

MD 2.76 higher
(1.36 lower to 6.87 higher)

274
(2 RCTs)

⊕⊕⊕⊕
High

Absolute difference 3% better (7% better to 1% worse); relative difference 9% better (22% better to 4% worse)c

Global assessment of treatment success

655 per 1000

708 per 1000
(610 to 832)

RR 1.08
(0.93 to 1.27)

290
(2 RCTs)

⊕⊕⊕⊝
Moderated

Absolute difference 5% more reported success (5% fewer to 16% more); relative difference 8% more reported success (7% fewer to 27% more)

Health‐related quality of life
(scale from −0.59 to 1, 1 is perfect health)
Follow‐up: 1 year

The mean health‐related quality of life was 0.73b

MD 0.03 lower
(0.11 lower to 0.06 higher)

285
(2 RCTs)

⊕⊕⊕⊕
High

SMD 0.09 worse (0.39 worse to 0.21 better)

Absolute difference 2% worse (7% worse to 4% better); relative difference 5% worse (20% worse to 11% better)c

Adverse events

37 per 1000

34 per 1000
(11 to 98)

RR 0.91
(0.31 to 2.65)

406
(2 RCTs)d

⊕⊕⊕⊝
Moderatee

Absolute difference of 1% fewer events with surgery (4% fewer to 3% more); relative difference 9% fewer events with surgery (69% fewer to 165% more)

Serious adverse events

No events

No events

No estimate

331
(2 RCTs)

⊕⊕⊕⊝
Moderatef

Although precise estimates are unknown, serious adverse event rates in observational studies are reported as less than 1%g

*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).

CI: confidence interval; MD: mean difference; RR: risk ratio; SMD: standardised mean difference

GRADE Working Group grades of evidence
High certainty: we are very confident that the true effect lies close to that of the estimate of the effect.
Moderate certainty: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different.
Low certainty: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect.
Very low certainty: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect.

aPain measured with numeric rating scale (NRS) or visual analogue scale (VAS).
bMedian value in placebo groups after one‐year follow‐up.
cRelative changes calculated relative to baseline in control group (i.e. absolute change (mean difference) divided by mean at baseline in the placebo group from Paavola 2018 (values were: 7.23 points on 0 to 10‐point VAS pain; 31.7 points on 0 to 100‐point Constant score) and Beard 2018 (0.55 points on EQ‐5D quality‐of‐life scale). Absolute change calculated as mean difference divided by scale of the instrument, expressed as percentage.

dPooled both placebo and non‐operative (exercise or no treatment) comparisons from randomised controlled trials in the analysis of adverse events
eDowngraded due to imprecision (due to low event rates, or 95% confidence intervals that included both benefits and harms) in the randomised trials.

fDowngraded due to indirectness as arthroscopic procedures other than subacromial decompression were included in the surgery registry observational data
gSerious adverse events as reported in observational studies, 7 per 1000 (95% CI 6 to 8 per 1000) include: deep infection; pulmonary embolism; uncontrolled bleeding; myocardial infection; acute renal failure; ventilation more than 48 hours; cerebral vascular incident; septic shock; cardiac arrest; wound dehiscence; deep venous thrombosis; pneumonia; bleeding requiring transfusion; nerve injury; death; organ space infection.

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Summary of findings for the main comparison. Subacromial decompression compared to placebo surgery
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Summary of findings 2. Subacromial decompression compared to exercises

Subacromial decompression compared to exercises for people with impingement syndrome without full‐thickness rotator cuff tears

Patient or population: people with impingement syndrome without full‐thickness rotator cuff tears
Setting: hospitals or home
Intervention: subacromial decompression
Comparison: exercises

Outcomes

Anticipated absolute effects* (95% CI)

Relative effect
(95% CI)

№ of participants
(studies)

Certainty of the evidence
(GRADE)

Comments

Risk with exercise

Risk with subacromial decompression

Paina
(scale from: 0‐10, 0 is no pain)
Follow‐up: 1 year

The mean pain was 3.7 pointsb

MD 1.01 better
(1.6 better to 0.42 better)

‐

316
(3 RCTs)

⊕⊕⊝⊝
Lowc

Absolute difference 10% better (4% better to 16% better); relative difference 14% better (6% better to 22% better)d

Functional outcomee

(scale from 0‐100, 100 is best)
Follow‐up: 1 year

The mean functional outcome was 58b

MD 3.24 better
(8.08 worse to 14.55 better)

‐

259
(3 RCTs)

⊕⊕⊝⊝
Lowc

Absolute difference 3% better (8% worse to 15% better); relative difference 9% better (23% worse to 41% better)d

Global assessment of treatment success

598 per 1000

723 per 1000
(574 to 902)

RR 1.21
(0.96 to 1.51)

158
(2 RCTs)

⊕⊕⊝⊝
Lowc

Absolute difference 13% more reported success (2% fewer to 30% more); relative difference 21% more reported success (4% fewer to 51% more)

Health‐related quality of life

(15D; scale from: 0‐1, 1 is perfect health)
Follow‐up: 1 year

The mean health‐related quality of life was 0.91b

MD 0.01 better
(0.01 worse to 0.03 better)

‐

116
(1 RCT)

⊕⊕⊝⊝
Lowc

Absolute difference 1% better (1% worse to 3% better); relative difference 1% better (1% worse to 3% better)d

Adverse events

37 per 1000

34 per 1000
(11 to 98)

RR 0.91
(0.31 to 2.65)

406
(2 RCTs)f

⊕⊕⊕⊝
Moderateg

Absolute difference of 1% fewer events with surgery (4% fewer to 3% more); relative difference 9% fewer events with surgery (69% fewer to 165% more)

Serious adverse events

No events

No events

Not estimable

⊕⊕⊕⊝
Moderateh

Although precise estimates are unknown, serious adverse events rates in observational studies are reported as less than 1%i

*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).

CI: confidence interval; MD: mean difference; RR: risk ratio

GRADE Working Group grades of evidence
High certainty: we are very confident that the true effect lies close to that of the estimate of the effect.
Moderate certainty: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different.
Low certainty: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect.
Very low certainty: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect.

aPain measured with numeric rating scale (NRS) or visual analogue scale (VAS).
bMedian value in exercise groups at one‐year follow‐up.
cDowngraded due to risk of bias and imprecision.
dRelative changes calculated as mean difference divided by mean at baseline in the exercise group from Paavola 2018 (mean (standard deviation) values were: 7.24 (2.08) points on 0 to 10‐point VAS pain scale; 35.2 (16.2) points on 0 to 100‐point Constant score); and 0.88 (0.08) points on 0 to 1 scale in health‐related quality of life. Absolute difference calculated as mean difference divided by scale of the instrument, expressed as percentage.
eFunctional outcome measured with various measures (Constant score, Shoulder Disability Questionnaire, Subjective Shoulder Rating scale, or Neer score).

fPooled both placebo and non‐operative (exercise or no treatment) comparisons from randomised controlled trials in the analysis of adverse events

gDowngraded due to imprecision (due to low event rates) in the randomised trials
hDowngraded due to indirectness as arthroscopic procedures other than subacromial decompression were included in the surgery registry observational data.
iSerious adverse events as reported in observational studies, 7 per 1000 (95% CI 6 to 8 per 1000) include: deep infection; pulmonary embolism; uncontrolled bleeding; myocardial infection; acute renal failure; ventilation more than 48 hours; cerebral vascular incident; septic shock; cardiac arrest; wound dehiscence; deep venous thrombosis; pneumonia; bleeding requiring transfusion; nerve injury; death; organ space infection.

Figures and Tables -
Summary of findings 2. Subacromial decompression compared to exercises
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Table 1. Baseline demographic and clinical characteristics of the trial participants

Trial

Country

Groups (number randomised)

Mean age, years

Mean symptom duration in months (duration specified in inclusion criteria)

Mean pain

Mean shoulder‐specific score

Mean HRQoL

Treatment delivered by

Beard 2018

UK

Subacromial decompression (106)

53

Not reported (≥ 3 months)

Not reported

39a

0.52

38 different surgeons

Placebo surgery (103)

54

43a

0.55

No treatment (104)

53

38a

0.50

Not specified

Brox 1993

Norway

Subacromial decompression (45)

48

Not reported (≥ 3 months)

Not reported

64b

Not measured

2 surgeons

Exercise therapy (50)

47

66

1 physiotherapist

Placebo‐laser (30)

48

65

1 physiotherapist

Farfaras 2016

Sweden

Open subacromial decompression (24)

52

Not reported (≥ 6 months)

Not reported

48a

69.6 (SF‐36 General Health)

Not specified

Arthroscopic subacromial decompression (29)

49

56a

60.1

Exercise therapy (34)

50

56a

67.3

Haahr 2005

Denmark

Subacromial decompression (45)

45

Not reported (6 months‐3 years)

5.9

35a

Not measured

2 surgeons

Exercise therapy (45)

44

6.5

34a

2 physiotherapists

Ketola 2009

Finland

Subacromial decompression (70)

46

31 (≥ 3 months)

6.5

78c

Not measured

One surgeon

Exercise therapy (70)

48

30 (≥ 3 months)

6.5

83c

Physiotherapist

Paavola 2018

Finland

Subacromial decompression (59)

51

18 (≥ 3 months)

7.1

32a

0.89 (15D)

Not specified

Placebo surgery (63)

51

18 (≥ 3 months)

7.2

32a

0.89

Exercise therapy (71)

50

22 (≥ 3 months)

7.2

35a

0.88

Peters 1997

Germany

Subacromial decompression (32)

56

Not reported (not reported)

Not measured

54d

Not measured

Not specified

Exercise therapy (40)

59

59d

Rahme 1998

Sweden

Subacromial decompression (21)

42

Not reported (≥ 12 months)

Not reported

Not measured

Not measured

Not specified

Exercise therapy (21)

42

aConstant score.
bNeer score.
cShoulder Disability Questionnaire.
dSubjective Shoulder Rating Scale.

Figures and Tables -
Table 1. Baseline demographic and clinical characteristics of the trial participants
Navigate to table in Review
Table 2. Deviations from allocated treatment

Trial

Group

Did not receive allocated treatment

Crossed over to active surgery

Re‐operated

Side interventions in surgery

Unblinded

Beard 2018

Subacromial decompression

19 (18%)

N/Aa

0

None reported

0 (0%)

Placebo surgery

35 (34%)

10 (10%)

0

None reported

1 (1%)

No treatment

26 (25%)

25 (24%)

0

No surgery

No blinding

Brox 1993

Subacromial decompression

13 (29%)

N/Aa

0

None reported

No blinding

Eexercise therapy

7 (14%)

1 (2%)

0

No surgery

Placebo‐laser

4 (13%)

2 (7%)

0

No surgery

Farfaras 2016

Open subacromial decompression

6 (25%)

N/Aa

0

None reported

No blinding

Arthroscopic subacromial decompression

5 (29%)

N/Aa

0

None reported

Exercise therapy

0

3 (9%)

0

No surgery

Haahr 2005

Subacromial decompression

4 (9%)

N/Aa

0

None reported

No blinding

Eercise therapy

2 (4%)

6 (13%) by 1 year
11 (24%) by 4‐8 years

0

No surgery

Ketola 2009

Subacromial decompression

13 (19%)

N/Aa

0

14 (20%) labrum repair

No blinding

Exercise therapy

0

5 (7%) by 1 year

14 (20%) by 2 years
18 (26%) by 5 years

0

No surgery

Paavola 2018

Subacromial decompression

0

N/Aa

2 (3%)

0 (0%)

6 (10%)

Placebo surgery

0

8 (13%)

8 (13%)

0 (0%)

9 (14%)

Exercise therapy

0

15 (21%)

3 (4%)

No surgery

No blinding

Peters 1997

Subacromial decompression

0

N/Aa

0

None reported

No blinding

Exercise therapy

0

0 (0%)

0

None reported

Rahme 1998

Subacromial decompression

0

N/Aa

0

5 rotator cuff tears were sutured

No blinding

Exercise therapy

0

13 (62%)

0

No surgery

aN/A (not applicable), participants in subacromial decompression group could not cross over to surgery.

Figures and Tables -
Table 2. Deviations from allocated treatment
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Table 3. Types and numbers of surgical procedures included in the two registry studies

Procedure

N (%) Hill 2017

N (%) Shields 2015

Rotator cuff repair

6399 (43)

3439 (33.5)

Subacromial decompression

2542 (16.9)

3362 (32.8)

Superior labrum lesion repair

1175 (7.8)

976 (9.5)

Capsuloraphy

1000 (6.7)

726 (7)

Distal clavicle resection

1029 (6.9)

544 (5.3)

Extensive debridement

1130 (7.5)

461 (4.5)

Limited debridement

1029 (6.9)

379 (3.7)

Lysis and resection of adhesion

279 (1.9)

149 (1.5)

Biceps tenodesis

263 (1.8)

105 (1)

Synovectomy

137 (0.9)

76 (0.7)

Foreign body removal

62 (0.4)

38 (0.4)

All

15,015

10,255

Figures and Tables -
Table 3. Types and numbers of surgical procedures included in the two registry studies
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Table 4. Risk of bias for registry studies of serious adverse events

Domain

Hill 2017

Shields 2015

Judgement

Study participation

Unsure, but judged unlikely to incur significant bias

Yes, large number of centres, judged likely to be representative

Unclear

Study attrition

Probably low risk given the tracking of participants who went elsewhere for care, and given follow‐up was 30 days

Probably low risk given the tracking of participants who went elsewhere for care, and given follow‐up was 30 days

Low

Prognostic factor measurement

Yes: arthroscopic procedure is the prognostic factor

Yes: arthroscopic procedure is the prognostic factor

Low

Outcome measurement

Yes: based on hospital record + participant contact call

Yes: based on hospital record + participant contact call

Low

Study confounding

Yes: total harms are of interest, no proper confounders

Yes: total harms are of interest, no proper confounders

Low

Statistical analysis and reporting

Unclear, judged not likely to lead to overestimation of harms

Unclear, judged not likely to lead to overestimation of harms

Low
Figures and Tables -
Table 4. Risk of bias for registry studies of serious adverse events
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Table 5. Serious adverse events in registry studies

Eventa

N (%) Hill 2017

N (%) Shields 2015

Mortality

2 (0.01)

4 (0.04)

Bleeding requiring transfusion

7 (0.05

5 (0.05)

Sepsis

0 (0)

1 (0.01)

Septic shock

3 (0.02)

2 (0.02)

Deep infection

1 (0.01)

1 (0.01)

Organ or space surgical site infection

3 (0.02)

2 (0.02)

Wound dehiscence

1 (0.01)

1 (0.01)

Deep vein thrombosis

21 (0.14)

8 (0.08)

Pulmonary embolism

20 (0.13)

7 (0.07)

Myocardial infarction

3 (0.02)

4 (0.04)

Cardiac arrest requiring cardiopulmonary

resuscitation

1 (0.01)

2 (0.02)

Cerebral vascular event

4 (0.03)

2 (0.02)

Acute renal failure

2 (0.01)

1 (0.01)

Pneumonia

13 (0.09)

7 (0.07)

Unplanned intubation

7 (0.05)

3 (0.03)

Ventilator > 48 hours

2 (0.01)

1 (0.01)

Peripheral nerve injury

2 (0.01)

2 (0.02)

aThese serious adverse events were recorded across all procedures in the registry and were not reported separately by procedure.

Figures and Tables -
Table 5. Serious adverse events in registry studies
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Comparison 1. Subacromial decompression vs placebo for rotator cuff disease

Outcome or subgroup title

No. of studies

No. of participants

Statistical method

Effect size

1 Pain (VAS or NRS 0‐10, lower is better) Show forest plot

2

Mean Difference (IV, Random, 95% CI)

Subtotals only

1.1 3 months

1

107

Mean Difference (IV, Random, 95% CI)

0.47 [‐0.45, 1.39]

1.2 6 months

2

299

Mean Difference (IV, Random, 95% CI)

0.07 [‐0.51, 0.64]

1.3 1 year

2

284

Mean Difference (IV, Random, 95% CI)

‐0.26 [‐0.84, 0.33]

1.4 2 years

1

118

Mean Difference (IV, Random, 95% CI)

‐0.9 [‐1.79, ‐0.01]

2 Functional outcome (Constant score 0‐100, 100 is best) Show forest plot

2

Mean Difference (IV, Random, 95% CI)

Subtotals only

2.1 6 months

2

286

Mean Difference (IV, Random, 95% CI)

‐3.72 [‐8.72, 1.28]

2.2 1 year

2

274

Mean Difference (IV, Random, 95% CI)

2.76 [‐1.36, 6.87]

2.3 2 years

1

117

Mean Difference (IV, Random, 95% CI)

4.20 [‐1.61, 10.01]

3 Global assessment of treatment success Show forest plot

2

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

3.1 6 months

2

293

Risk Ratio (M‐H, Random, 95% CI)

1.17 [0.89, 1.54]

3.2 1 year

2

290

Risk Ratio (M‐H, Random, 95% CI)

1.08 [0.93, 1.27]

3.3 2 years

1

116

Risk Ratio (M‐H, Random, 95% CI)

0.98 [0.82, 1.17]

4 Health‐related quality of life (various measures, higher is better) Show forest plot

2

Std. Mean Difference (IV, Random, 95% CI)

Subtotals only

4.1 3 months

1

109

Std. Mean Difference (IV, Random, 95% CI)

‐0.17 [‐0.55, 0.21]

4.2 6 months

2

292

Std. Mean Difference (IV, Random, 95% CI)

‐0.05 [‐0.27, 0.18]

4.3 1 year

2

285

Std. Mean Difference (IV, Random, 95% CI)

‐0.09 [‐0.39, 0.21]

4.4 2 years

1

118

Std. Mean Difference (IV, Random, 95% CI)

0.0 [‐0.36, 0.36]

5 Participation (number at work) Show forest plot

1

Risk Ratio (M‐H, Random, 95% CI)

Totals not selected

5.1 3 months

1

Risk Ratio (M‐H, Random, 95% CI)

0.0 [0.0, 0.0]

5.2 6 months

1

Risk Ratio (M‐H, Random, 95% CI)

0.0 [0.0, 0.0]

5.3 1 year

1

Risk Ratio (M‐H, Random, 95% CI)

0.0 [0.0, 0.0]

5.4 2 years

1

Risk Ratio (M‐H, Random, 95% CI)

0.0 [0.0, 0.0]

6 Participation (number returning to sport or leisure activities) Show forest plot

1

Risk Ratio (M‐H, Random, 95% CI)

Totals not selected

6.1 3 months

1

Risk Ratio (M‐H, Random, 95% CI)

0.0 [0.0, 0.0]

6.2 6 months

1

Risk Ratio (M‐H, Random, 95% CI)

0.0 [0.0, 0.0]

6.3 1 year

1

Risk Ratio (M‐H, Random, 95% CI)

0.0 [0.0, 0.0]

6.4 2 years

1

Risk Ratio (M‐H, Random, 95% CI)

0.0 [0.0, 0.0]
Figures and Tables -
Comparison 1. Subacromial decompression vs placebo for rotator cuff disease
Navigate to table in Review
Comparison 2. Subacromial decompression vs exercise treatment for rotator cuff disease

Outcome or subgroup title

No. of studies

No. of participants

Statistical method

Effect size

1 Pain (VAS 0‐10, 0 is no pain) Show forest plot

4

Mean Difference (IV, Random, 95% CI)

Subtotals only

1.1 3 months

4

361

Mean Difference (IV, Random, 95% CI)

‐0.55 [‐1.24, 0.14]

1.2 6 months

4

399

Mean Difference (IV, Random, 95% CI)

‐0.56 [‐1.09, ‐0.02]

1.3 1 year

3

316

Mean Difference (IV, Random, 95% CI)

‐1.01 [‐1.60, ‐0.42]

1.4 2 years

3

352

Mean Difference (IV, Random, 95% CI)

‐0.44 [‐1.37, 0.49]

1.5 5 years

2

188

Mean Difference (IV, Random, 95% CI)

0.36 [‐1.17, 1.89]

1.6 10 years

1

90

Mean Difference (IV, Random, 95% CI)

1.00 [‐0.25, 2.25]

2 Functional outcome (0‐100, 100 is best) Show forest plot

6

Mean Difference (IV, Random, 95% CI)

Subtotals only

2.1 3 months

3

257

Mean Difference (IV, Random, 95% CI)

6.11 [‐5.57, 17.79]

2.2 6 months

4

398

Mean Difference (IV, Random, 95% CI)

3.66 [‐2.25, 9.58]

2.3 1 year

3

259

Mean Difference (IV, Random, 95% CI)

3.24 [‐8.08, 14.55]

2.4 2 years

5

467

Mean Difference (IV, Random, 95% CI)

4.94 [0.77, 9.11]

2.5 5 years

2

157

Mean Difference (IV, Random, 95% CI)

7.63 [0.17, 15.09]

2.6 10 years

2

156

Mean Difference (IV, Random, 95% CI)

9.54 [1.93, 17.15]

3 Global assessment of treatment success Show forest plot

4

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

3.1 6 months

2

161

Risk Ratio (M‐H, Random, 95% CI)

1.47 [0.74, 2.91]

3.2 1 year

2

158

Risk Ratio (M‐H, Random, 95% CI)

1.21 [0.96, 1.51]

3.3 2 years

1

126

Risk Ratio (M‐H, Random, 95% CI)

1.25 [1.00, 1.57]

3.4 5 years

1

79

Risk Ratio (M‐H, Random, 95% CI)

0.87 [0.62, 1.23]

3.5 10 years

1

90

Risk Ratio (M‐H, Random, 95% CI)

1.00 [0.67, 1.49]

4 Health‐related quality of life (various measures, 0‐1; higher is better) Show forest plot

3

Std. Mean Difference (IV, Random, 95% CI)

Subtotals only

4.1 3 months

1

119

Std. Mean Difference (IV, Random, 95% CI)

0.13 [‐0.23, 0.49]

4.2 6 months

1

119

Std. Mean Difference (IV, Random, 95% CI)

0.51 [0.15, 0.88]

4.3 1 year

1

116

Std. Mean Difference (IV, Random, 95% CI)

0.16 [‐0.21, 0.52]

4.4 2 years

2

181

Std. Mean Difference (IV, Random, 95% CI)

0.13 [‐0.22, 0.48]

4.5 5 years

1

86

Std. Mean Difference (IV, Random, 95% CI)

0.12 [‐0.30, 0.54]

4.6 10 years

2

155

Std. Mean Difference (IV, Random, 95% CI)

0.30 [‐0.01, 0.62]

5 Participation (number at work) Show forest plot

4

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

5.1 3 months

1

127

Risk Ratio (M‐H, Random, 95% CI)

0.96 [0.75, 1.22]

5.2 6 months

2

187

Risk Ratio (M‐H, Random, 95% CI)

1.05 [0.81, 1.36]

5.3 1 year

1

119

Risk Ratio (M‐H, Random, 95% CI)

0.98 [0.85, 1.13]

5.4 2 years

2

183

Risk Ratio (M‐H, Random, 95% CI)

0.87 [0.70, 1.07]

5.5 5 years

2

188

Risk Ratio (M‐H, Random, 95% CI)

1.13 [0.97, 1.32]

5.6 10 years

1

90

Risk Ratio (M‐H, Random, 95% CI)

1.07 [0.97, 1.18]

6 Participation (numbers returning to sport or leisure activities) Show forest plot

1

Risk Ratio (M‐H, Random, 95% CI)

Totals not selected

6.1 3 months

1

Risk Ratio (M‐H, Random, 95% CI)

0.0 [0.0, 0.0]

6.2 6 months

1

Risk Ratio (M‐H, Random, 95% CI)

0.0 [0.0, 0.0]

6.3 1 year

1

Risk Ratio (M‐H, Random, 95% CI)

0.0 [0.0, 0.0]

6.4 2 years

1

Risk Ratio (M‐H, Random, 95% CI)

0.0 [0.0, 0.0]

7 Treatment failure Show forest plot

2

Risk Ratio (M‐H, Random, 95% CI)

Totals not selected

7.1 5 years

1

Risk Ratio (M‐H, Random, 95% CI)

0.0 [0.0, 0.0]

7.2 13 years

1

Risk Ratio (M‐H, Random, 95% CI)

0.0 [0.0, 0.0]
Figures and Tables -
Comparison 2. Subacromial decompression vs exercise treatment for rotator cuff disease
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Comparison 3. Subacromial decompression vs no treatment for rotator cuff disease

Outcome or subgroup title

No. of studies

No. of participants

Statistical method

Effect size

1 Pain (NRS 0‐10 lower is better) Show forest plot

1

Mean Difference (IV, Random, 95% CI)

Totals not selected

1.1 6 months

1

Mean Difference (IV, Random, 95% CI)

0.0 [0.0, 0.0]

1.2 1 year

1

Mean Difference (IV, Random, 95% CI)

0.0 [0.0, 0.0]

2 Functional outcomes (Constant score 0‐100, 100 is best) Show forest plot

1

Mean Difference (IV, Random, 95% CI)

Totals not selected

2.1 6 months

1

Mean Difference (IV, Random, 95% CI)

0.0 [0.0, 0.0]

2.2 1 year

1

Mean Difference (IV, Random, 95% CI)

0.0 [0.0, 0.0]

3 Global assessment of treatment success Show forest plot

1

Risk Ratio (M‐H, Random, 95% CI)

Totals not selected

3.1 6 months

1

Risk Ratio (M‐H, Random, 95% CI)

0.0 [0.0, 0.0]

3.2 1 year

1

Risk Ratio (M‐H, Random, 95% CI)

0.0 [0.0, 0.0]

4 Health‐related quality of life (EQ‐5D 3L −0.59 to 1, higher is better) Show forest plot

1

Mean Difference (IV, Random, 95% CI)

Totals not selected

4.1 6 months

1

Mean Difference (IV, Random, 95% CI)

0.0 [0.0, 0.0]

4.2 1 year

1

Mean Difference (IV, Random, 95% CI)

0.0 [0.0, 0.0]
Figures and Tables -
Comparison 3. Subacromial decompression vs no treatment for rotator cuff disease
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Comparison 4. Harms: Subacromial decompression versus non‐operative treatment

Outcome or subgroup title

No. of studies

No. of participants

Statistical method

Effect size

1 Total adverse events Show forest plot

2

406

Risk Ratio (M‐H, Random, 95% CI)

0.91 [0.31, 2.65]
Figures and Tables -
Comparison 4. Harms: Subacromial decompression versus non‐operative treatment
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Comparison 5. Sensitivity analysis (subacromial decompression vs exercises or placebo for rotator cuff disease)

Outcome or subgroup title

No. of studies

No. of participants

Statistical method

Effect size

1 Pain at 6 months (VAS or NRS 0‐10, higher is better) Show forest plot

5

639

Mean Difference (IV, Random, 95% CI)

‐0.31 [‐0.75, 0.12]

1.1 Surgery vs placebo‐surgery (blinded)

2

270

Mean Difference (IV, Random, 95% CI)

0.07 [‐0.55, 0.69]

1.2 Surgery vs non‐surgical therapy (unblinded)

4

369

Mean Difference (IV, Random, 95% CI)

‐0.55 [‐1.11, 0.02]

2 Pain at 1 year (VAS or NRS 0‐10, higher is better) Show forest plot

4

532

Mean Difference (IV, Random, 95% CI)

‐0.58 [‐1.05, ‐0.12]

2.1 Surgery vs placebo‐surgery (blinded)

2

257

Mean Difference (IV, Random, 95% CI)

‐0.22 [‐0.85, 0.40]

2.2 Surgery vs any conservative or no therapy (unblinded)

3

275

Mean Difference (IV, Random, 95% CI)

‐0.94 [‐1.57, ‐0.31]

3 Function at 6 months (various measures 0‐100, higher is better) Show forest plot

5

625

Mean Difference (IV, Random, 95% CI)

1.05 [‐3.77, 5.87]

3.1 Surgery vs placebo‐surgery (blinded)

2

257

Mean Difference (IV, Random, 95% CI)

‐3.30 [‐8.25, 1.65]

3.2 Surgery vs conservative or no treatment (unblinded)

4

368

Mean Difference (IV, Random, 95% CI)

3.82 [‐2.40, 10.05]

4 Function at 1‐3 years (various measures, higher is better) Show forest plot

7

737

Mean Difference (IV, Random, 95% CI)

3.21 [‐0.81, 7.23]

4.1 Surgery vs placebo‐surgery

2

245

Mean Difference (IV, Random, 95% CI)

2.46 [‐2.05, 6.98]

4.2 Surgery vs any non‐surgical therapy

6

492

Mean Difference (IV, Random, 95% CI)

3.72 [‐2.29, 9.72]

5 Pain at 1 year Show forest plot

5

733

Mean Difference (IV, Random, 95% CI)

‐0.78 [‐1.17, ‐0.39]
Figures and Tables -
Comparison 5. Sensitivity analysis (subacromial decompression vs exercises or placebo for rotator cuff disease)
Navigate to table in Review