Septic Arthritis: The drainage controversy

Objective: Septic arthritis is a relatively rare disease, which is associated with a high morbidity and mortality. Treatment consists of prolonged antibiotic therapy and removal of intra-articular infl ammatory debris. However, there is much controversy about the most effective drainage method. Therefore, we compared the clinical effi cacy of (daily) needle aspiration with surgical drainage in adult patients with septic arthritis. Methods: In this systemic review, all articles describing treatment outcomes based upon the drainage method were retrieved. We also performed a meta-analysis, irrespective of the clinical or methodological heterogeneity. Results: We included 5 studies, all retrospective in nature, and if combined, with a total number of 450 patients. These studies showed that complete rehabilitation occurred more often in septic arthritis patients treated with needle aspirations (67-76%) compared to surgically treated patients (32-56%). The pooled relative risk (RR) (95% confi dence interval (CI)) for complete rehabilitation in needle aspirations compared to surgical drainage was 1.46 (1.22–1.75). On the other hand, the mortality rate was slightly higher in the daily aspiration group (respectively 3-13% versus 2.5-5%). The pooled RR (95% CI) for mortality in needle aspiration versus surgical treatment was 2.23 (0.84-5.91). Noteworthy is the fact that serious underlying illnesses were more frequent in the needle aspiration group. Conclusion: We recommend (daily) needle aspirations as initial method of drainage in patients with an uncomplicated septic arthritis, except for following more complex/diffi cult situations, in which surgical drainage is preferred: (1) inaccessible joints; (2) unsatisfactory clinical response; and (3) inability to aspirate the joint dry. Case Report Septic Arthritis: The drainage controversy de Jong PH1*, Bisoendial RJ2 and Lems WF3 1Department of Rheumatology, Erasmus University Medical Center, Rotterdam 2Department of Rheumatology, Maasstad Hospital, Rotterdam 3Department of Rheumatology, VU University Medical Center, Amsterdam Received: 10 September, 2018 Accepted: 22 September, 2018 Published: 24 September, 2018 *Corresponding author: Pascal Hendrik Pieter de Jong, ErasmusMC, room NB-848,Postbus 2040, 3000CA Rotterdam, Netherlands, Tel: +31 10 – 7034602; E-mail:

• (Daily) needle aspirations are advised as initial drainage method in patients with a septic arthritis.

Introduction
Patients frequently present to the emergency department with one or more warm, swollen joints, which has a broad differential diagnosis, but one should never overlook a septic arthritis. The latter represents a relatively rare disease with a reported incidence of 4-10 per 100.000 person-years, but its course may have a signifi cant impact on patients' life, including irreversible joint destruction with subsequent disability and death [1]. Septic arthritis has a mortality of approximately immune system (ie. by the use of immunosuppressive drugs), prosthetic joint(s), intravenous drug abuse, diabetes mellitus, skin defect(s) and/or pre-existing joint disease [4]. There is a predilection for the knee and hip joints, that are respectively involved in 48% and 21% of patients with a septic arthritis [5].
The diagnosis septic arthritis is established by detecting bacteria in synovial fl uid, but is most often made by integration of history, physical examination and laboratory testing.
The predominant causative pathogens in septic arthritis are Staphylococcus aureus and Streptococcus, accounting for respectively 65% and 25-30% of cases [5]. Treatment consists of prolonged (intravenous) antibiotic therapy and removal of intra-articular pus [1].
The latter can be done either surgically, via arthroscopy, or through daily needle aspirations. The drainage method currently seems to depend on the specialization of the attending physician. Thus, rheumatologists prefer daily needle aspirations, whereas orthopedic surgeons are more inclined to surgical drainage [6]. Both drainage methods have their advantages and disadvantages.
Surgical drainage allows better access and exposure of the joint, which facilitates adhesiolysis, debridement and incision of perisynovial abscesses [2]. However, the procedure is associated with more risks/complications. Also it can often be performed only once and it depends on the availability of the operation theatre [2]. Daily needle aspirations on the other hand are relatively noninvasive and can be performed repeatedly and practically everywhere [2]. Disadvantages are that not all purulent material can be evacuated and some joints are inaccessible [2].
Due to abovementioned arguments controversy persists with regards to the most effective drainage method. Therefore, the aim of this review is to compare the clinical effi cacy of (daily) needle aspiration versus surgical drainage in adult patients with septic arthritis.

Outcome and statistical analysis
We identifi ed three major outcomes, namely: (1) percentage of complete rehabilitation in all infected joints, (2) percentage of complete rehabilitation of the knee and (3) mortality. For the meta-analysis we included all studies, which compared both drainage methods in patients with a septic arthritis, irrespective of their clinical or methodological heterogeneity. The treatment effect was estimated using a relative risk (RR) with 95% confi dence intervals (CI) for each study independently. Pooled estimates were provided using fi xedeffects models with the sample size of each reported outcome per study as weight. Forest plots are given to summarize the results. All statistical analyses were carried out using STATA V.12.0. A p value <0.05 was considered statistically signifi cant.

Guidelines
The Dutch Orthopedic Association and the Dutch Society for Rheumatology do not provide a national guideline for the management of septic arthritis. Also, no guidelines/ recommendations are available from the American College of Rheumatology (ACR) and European League Against Rheumatism (EULAR).
However, after our thorough literature search we found the British guidelines for the management of the hot swollen joint in adults [7]. In this guideline, last updated in 2006, no preference to either drainage method was given. However, in the following cases aforementioned guideline recommends surgical drainage over daily needle aspiration: (A) unsatisfactory response to daily needle aspiration, and (B) septic arthritis of the hip. These recommendations are based on data from a few retrospective studies, which will be discussed in the next paragraphs [7].

Articles
The previously described search strategy identifi ed 132 articles for potential selection. After review of the titles and abstracts, 7 articles were found to fulfi l the inclusion criteria. Three of the 7 articles were reviews, of these 2 were excluded, because they refer to the remaining studies [2,8]. The study characteristics of the 5 articles, included in this systemic review, are given in table 1 [6,[9][10][11][12]. The 5 selected, all retrospective, studies will be discussed separately in following paragraphs [6,[9][10][11][12]. These cohort studies compared the effectiveness of both drainage techniques by complete rehabilitation and mortality. However, in the studies of Goldenberg, Rosenthal and Bynum, it is unclear when these outcomes are measured [6,[9][10][11][12].
In our meta-analysis we excluded the studies from Goldenburg and Bynum, because both studies are included in the review from Broy [6,[9][10][11][12]. The results of the metaanalysis are given in fi gure 1. The pooled relative risk (RR) (95% confi dence interval (CI)) for complete rehabilitation in patients treated with (daily) needle aspirations compared to patients treated with surgical drainage was 1.46 (1.22 -1.75).
We also performed a subgroup analysis, including all patients with a septic arthritis of the knee, because this is the most frequently involved joint. In this subgroup, the pooled RR (95%) for complete rehabilitation in the daily aspiration group compared to the surgical group was 1.45 (1.14 -1.84). On the other hand, the mortality rate is slightly higher in the daily aspiration group. The pooled RR (95% CI) for mortality in daily aspiration versus surgical treatment was 2.23 (0.84 -5.91).

Discussion
Septic arthritis is a relatively rare but severe disease, which is associated with high morbidity and mortality.(1) Early recognition and appropriate treatment is paramount to a better outcome [13]. Treatment consist of prolonged (intravenous) antibiotic therapy and drainage of the involved joint(s) [1].
However, there is much controversy about the most effective drainage method. In general, orthopedic surgeons are in favor of surgical drainage, where rheumatologists prefer (daily) needle aspirations [6].
In this review we discussed the available literature on the clinical effi cacy and safety of both drainage methods.
Another point is of course the cost of treatment, the costs of daily drainage by a rheumatologist should be compared to the surgical procedure, including operating room, nurses, anesthesia, and the orthopedic surgeon.
In conclusion, there is a lack of high quality data, preferably derived from RCTs, that address the clinically relevant question with regards to the optimal synovial drainage in septic arthritis. Plausible explanations for the absence of these RCTs are the low incidence of septic arthritis, the strong belief by rheumatologists as well as orthopedics that their strategy is superior, and fi nally the lack of interest of pharmaceutical companies. We suggest that, probably, independent organizations that fi nancially support multicenter RCTs, over some years, may or should be able and willingly to fi ll this important knowledge gap.  As for now, we recommend (daily) needle aspirations as preferred drainage method in patients with an uncomplicated septic arthritis. The following more complex cases, may demand surgical drainage over (daily) needle aspirations: (1) inaccessible joints (ie. the hip); (2) unsatisfactory clinical response after 3-5 days; and (3) inability to aspirate the joint dry.