Surgical versus non‐surgical treatment for acute anterior shoulder dislocation
Abstract
This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:
The objective of this review is to compare surgical with non‐surgical interventions for treating acute anterior shoulder dislocation.
We thus aim to test the following null hypothesis:
There are no differences in outcome between surgical and non‐surgical interventions for treating acute anterior shoulder dislocation.
The main focus will be on physically active individuals with primary dislocation who fall in the late adolescent to young adult category (nominally defined as between 16 and 30 years). This is mainly because there is some evidence that these individuals have highest risk of recurrent dislocation.
If the data are available, we plan to test the following null hypotheses by patient group:
There are no differences in outcome between patients with primary dislocations and those with recurrent dislocations.
There are no differences in outcome between physically active young to middle‐aged adults and those not falling into this category.
Background
Of the large joints, the shoulder is the one that most commonly dislocates. The shoulder joint has the greatest range of motion of all the joints in the human body. It is this extreme range of motion that also renders the shoulder the most unstable joint in the body (Kazar 1969). Gleno‐humeral (shoulder joint) instability encompasses a spectrum of disorders (O'Brien 1987). These vary in degree of dislocation, from partial dislocation or subluxation to full dislocation where the bone ends are no longer in contact; in direction, either anterior (forwards), posterior (backwards) or multidirectional; whether they are acute, recurrent or chronic; and their etiology, for instance resulting from a traumatic event or spontaneously, perhaps due to some congenital joint laxity.
Anterior traumatic dislocation, where the proximal end of humerus (upper arm bone) is pushed out of the joint socket in a forward direction, constitutes 96% of all shoulder dislocations (Goss 1988). Once a dislocation has occurred, the shoulder is less stable and more susceptible to re‐dislocation. Recurrence has been reported to be as high as 92% (Rowe 1956).
An epidemiological study (Hovelius 1982) conducted in Sweden, reported an incidence of shoulder dislocation of 1.7% in the 18 to 70 years age group; with a male to female ratio of three to one. This sex ratio varied with age. In the 21 to 30 age group, Hovelius recorded a nine to one male predominance, whereas there was a three to one female predominance in the 50 to 70 age group. A study based in the USA reported an overall adjusted incidence of initial traumatic shoulder dislocation of 8.2/100,000 person‐years (Simonet 1984). The incidence of all traumatic shoulder dislocations, initial and recurrent, was estimated to be at least 11.2/100,000 person‐years. Simonet et al. further estimated a cumulative incidence rate of 0.7% for men and 0.3% for women (Simonet 1984). Although shoulder dislocation is generally considered an injury of young adults, Rowe found that there were as many initial dislocations after age 45 as before age 45 (Rowe 1956). However, recurrent dislocation tends to be more common in younger adults. For instance, a 10 year follow‐up evaluation found that 66% of those aged between 12 and 22 years at the time of their first dislocation had one or more recurrences; whereas it was 24% in those aged between 30 and 40 years (Hovelius 1996).
Traumatic shoulder dislocation, which involves a complete separation of the joint surfaces, usually results in damage to the soft‐tissue surrounding the shoulder joint. While the nature and extent of damage varies, there are some frequently found injury patterns such as the classical Bankart lesion (the separation of anterior capsule and labrum from the glenoid rim) (Bankart 1938), the Hill Sachs lesion (compression fracture of the humeral head) (McLaughlin 1956) or dysfunction of the subscapularis muscle (De Palma 1973), are considered as the key lesions associated with shoulder dislocation.
There is no single pathologic lesion that is common to all recurrent dislocations (Morrey 1981). Fleega devised an anatomical classification to describe the pathology of recurrent dislocation. This includes the capsule and ligaments, the glenoid, the humeral head and the muscles or muscle tendons; defects in each one of these or in combination can cause recurrent dislocation (Fleega 1991).
Shoulder dislocation and its treatment has been recorded since ancient times. Hippocrates, in his writings, revealed firm convictions regarding the different types of recurrent dislocation, the seriousness of the lesions and methods of treatment. His treatments included the cauterisation of the deep tissues in front of the shoulder for chronic instability (De Palma 1973).
Present day treatment, which aims at restoration of a fully functioning, pain‐free and stable shoulder, comprises either conservative (non‐surgical) or surgical management. Both are generally preceded by reduction of the acute dislocation. Subsequent conservative management usually comprises a period of rest, generally involving immobilisation of the arm in a sling, for three to six weeks followed by a supervised physiotherapy programme (O'Brien 1987). Operative management, which may involve open or arthroscopic surgery, is usually followed by a supervised physiotherapy programme. Nowadays, surgical interventions generally aim to restore normal anatomy, such as the Bankart procedure involving repair of the Bankart lesion. However, in some surgical methods, such as the Putti‐Platt procedure, tendon or muscles are transferred in an attempt to stabilise and strengthen the shoulder joint.
In essence, there is a spectrum of treatment ranging from initial immobilisation followed by rehabilitation to immediate surgical repair in selected cases (Hawkins 1991). The choice of treatment will be influenced by patient age and previous history of dislocation, occupation, level of activity, general health, ligamentous laxity and the reliability to carry out a prescribed therapeutic regime. Generally, surgical intervention has been reserved for chronic recurrence/instability. However, given the high rate of recurrence, especially in young physically active adults, a key area of controversy is the management of the traumatic first‐time anterior dislocation and whether surgical treatment of primary dislocation is warranted.
Thus, the main focus of this review is whether a patient within the late adolescent to middle‐aged adult category presenting with first time dislocation should be offered surgical treatment. We will also address this question for the whole population, including children and older adults. However, we anticipate that there will be no randomised controlled trials specific to children, in whom anterior shoulder dislocation is rare, or older adults, whose risk of recurrence is less.
Objectives
The objective of this review is to compare surgical with non‐surgical interventions for treating acute anterior shoulder dislocation.
We thus aim to test the following null hypothesis:
There are no differences in outcome between surgical and non‐surgical interventions for treating acute anterior shoulder dislocation.
The main focus will be on physically active individuals with primary dislocation who fall in the late adolescent to young adult category (nominally defined as between 16 and 30 years). This is mainly because there is some evidence that these individuals have highest risk of recurrent dislocation.
If the data are available, we plan to test the following null hypotheses by patient group:
There are no differences in outcome between patients with primary dislocations and those with recurrent dislocations.
There are no differences in outcome between physically active young to middle‐aged adults and those not falling into this category.
Methods
Criteria for considering studies for this review
Types of studies
Any randomised or quasi‐randomised (for example, allocation by date of birth or alternation) controlled trials which compare surgical and non‐surgical interventions for the treatment of acute anterior shoulder dislocation.
Types of participants
Patients with acute anterior shoulder dislocation, which has been confirmed by physical examination and radiography (X‐ray) or, more rarely, some other imaging modality such as magnetic resonance imaging (MRI). The potential for misdiagnosis, such as a missed proximal humeral fracture, will be considered in trials in which the method of diagnosis is unspecified or based on physical examination alone.
Types of interventions
Any surgical (open or minimal access) treatment intervention when compared with a non‐surgical treatment intervention for acute anterior shoulder dislocation.
Types of outcome measures
The primary outcome measures sought will be:
1. Recovery defined as return to pre‐injury level of activity (sports/work)
2. Re‐injury or recurrence (including subsequent surgery)
3. Persistent pain (long‐term)
4. Subjective instability
5. Results from patient functional assessment measures such as Short Form‐36 (SF‐36), the Disability of the Arm, Shoulder, and Hand questionnaire (DASH) and other validated shoulder rating scales.
Secondary outcomes will be:
6. Objective instability (e.g. apprehension test)
7. Stiffness
8. Range of movement
9. Muscle strength
10. Complications (e.g. sensory deficit, infection, osteoarthritis)
11. Satisfaction
In addition, note will be taken of reports of service utilisation or resource use; for instance, length of hospital stay, outpatient attendance and the provision and nature of physiotherapy.
Search methods for identification of studies
We will search the Cochrane Musculoskeletal Injuries Group specialised register (to present), the Cochrane Central Register of Controlled Trials (The Cochrane Library current issue), MEDLINE (1966 to present), EMBASE (1988 to present), the National Research Register (UK) and reference lists of articles. We will also contact researchers in the field.
In MEDLINE (OVID ONLINE) the following subject‐specific strategy will be combined with the revised Cochrane trial search strategy (Robinson 2002) and modified for use in other databases:
1. Shoulder Dislocation/
2. (shoulder$ adj3 (dislocat$ or sublux$ or instability or unstable)).tw.
3. (glenohumeral adj (joint or instability or unstable)).tw.
4. hill sachs lesion.tw.
5. or/1‐4
6. Bankart.tw.
7. Putti‐Platt.tw.
8. (arthroscop$ or repair$ or operation or surgery or stabilis$ or stabiliz$).tw.
9. su.fs.
10. or/6‐9
11. and/5,10
There will be no restriction applied to reports in other languages.
Data collection and analysis
All three reviewers will assess potentially eligible trials for inclusion and any disagreement resolved through discussion. Titles of journals, names of authors or supporting institutions will not be masked at any stage. The methodological quality of included studies will be assessed and the data extracted independently by two reviewers (MA and HH). Any outstanding disagreement or discrepancies will be resolved through discussions involving all three reviewers.
Attempts will be made to contact trialists for additional details of key items of trial methodology or data.
A modification of the Cochrane Musculoskeletal Injuries Group quality assessment tool will be used in the evaluation of the included studies.
The scoring scheme for 12 aspects of trial validity, plus brief notes of coding guidelines for selected items, are given below. Though the scores of the individual items will be summed, this will be to gain an overall impression rather than for quantitative purposes.
A. Was the assigned treatment adequately concealed prior to allocation?
2 = method did not allow disclosure of assignment.
1 = small but possible chance of disclosure of assignment or unclear.
0 = quasi‐randomised or open list/tables.
Cochrane code: Clearly Yes = A; Not sure = B; Clearly No = C.
B. Were the outcomes of participants who withdrew described and included in the analysis (intention to treat)?
2 = withdrawals well described and accounted for in analysis.
1 = withdrawals described and analysis not possible.
0 = no mention, inadequate mention, or obvious differences and no adjustment.
C. Were the outcome assessors blinded to treatment status?
2 = effective action taken to blind assessors.
1 = small or moderate chance of unblinding of assessors, or some blinding of outcomes attempted.
0 = not mentioned or not possible.
D. Were important baseline characteristics reported and comparable?
The principal confounders considered will be age, time since injury, primary or repeat dislocation, previous upper‐arm injury, presence of other shoulder injuries, hand dominance and type of sporting activity.
2 = good comparability of groups, or confounding adjusted for in analysis.
1 = confounding small, mentioned but not adjusted for, or comparability reported in text without confirmatory data.
0 = large potential for confounding, or not discussed.
E. Were the participants blind to assignment status after allocation?
2 = effective action taken to blind participants.
1 = small or moderate chance of unblinding of participants.
0 = not possible, or not mentioned (unless double‐blind), or possible but not done.
F. Were the treatment providers blind to assignment status?
2 = effective action taken to blind treatment providers.
1 = small or moderate chance of unblinding of treatment providers.
0 = not possible, or not mentioned (unless double‐blind), or possible but not done.
G. Were care programmes, other than the trial options, identical?
Examples of clinically important differences in other interventions are: differences in anaesthesia, clinician experience and speciality (fully trained orthopaedic surgeons, others), and subsequent rehabilitation.
2 = care programmes clearly identical.
1 = clear but trivial differences, or some evidence of comparability.
0 = not mentioned or clear and important differences in care programmes.
H. Were the inclusion and exclusion criteria for entry clearly defined?
2 = clearly defined (including whether primary or secondary dislocation).
1 = inadequately defined.
0 = not defined.
I. Were the interventions clearly defined?
2 = clearly defined interventions are applied with a standardised protocol.
1 = clearly defined interventions are applied but the application protocol is not standardised.
0 = intervention and/or application protocol are poorly or not defined.
J. Were the outcome measures used clearly defined?
2 = clearly defined.
1 = inadequately defined.
0 = not defined.
K. Were the outcome measures/diagnostic tests used in outcome assessment appropriate?
2 = optimal.
1 = adequate.
0 = not defined or adequate.
L. Was the surveillance active and of clinically appropriate duration?
2 = active surveillance and appropriate duration (1 year or more).
1 = active surveillance, but inadequate duration.
0 = surveillance not active or not defined.
Data analysis
Where available and appropriate, quantitative data for outcomes listed in the inclusion criteria will be presented in the analysis tables. Relative risks and 95 per cent confidence limits will be calculated for dichotomous outcomes, and mean differences and 95 per cent confidence limits calculated for continuous outcomes. Results of comparable groups of trials will be pooled using the fixed effects model and 95 per cent confidence limits. Heterogeneity between comparable trials will be tested using a standard chi‐squared test and considered statistically significant at p < 0.1. Where there is significant heterogeneity, we will view the results of the random effects model and present these when appropriate.
Sensitivity and subgroup analyses
Where appropriate, we will perform sensitivity analyses investigating the effects of allocation concealment, assessor blinding and loss to follow‐up. Where data allow, we also plan separate outcome analyses of a) patients with primary dislocations compared with those with recurrent dislocations and b) physically active young to middle‐aged adults who constitute the main category of people at risk of this injury and those not falling into this category. Where appropriate, indirect comparisons of fundamentally different treatment interventions, such as open and arthroscopic surgery, will be performed. These, however, are not intended to pre‐empt the need for direct comparisons of different types of surgical or non‐surgical treatment options which we hope will be the basis of subsequent reviews. Any tests of interaction calculated to determine if the results for subgroups are significantly different will be based on Peto odds ratio results.
