Subgroups of patients with osteoarthritis and medial meniscus tear or crystal arthropathy benefit from arthroscopic treatment.

Purpose: The purpose of this study was to perform a systematic review of prospective randomized controlled trials comparing arthroscopic treatment for knee osteoarthritis (OA) with either other therapeutic interventions or sham treatment.
Methods: A systematic search for randomized controlled trials (RCT) about arthroscopic treatment (AT) for knee OA was performed according to the PRISMA guidelines. Arthroscopic treatment included procedures such as lavage, debridement and partial meniscectomy of the knee. Data source was PubMed central.
Results: Fourteen articles could be included. Five studies compared interventive AT with either sham surgery, lavage or diagnostic arthroscopy. Nine trials compared AT with another active intervention (exercise, steroid injection, hyaluronic acid injection). In ten trials, the clinical scores improved after arthroscopic treatment of knee OA in comparison to the baseline. In seven trials, there was a significant difference in the final clinical outcome with higher scores for patients after arthroscopic OA treatment in comparison to a control group. In four trials, the intention to treat analysis revealed no significant difference between arthroscopic OA treatment and the control group. In one of those trials, which compared arthroscopic partial meniscectomy (APM) with exercise, the cross over rate from exercise to AT was 34.9%. The clinical scores of cross-over patients improved after APM. In one study, the subgroup analysis revealed that patients with tears of the anterior two-thirds of the medial meniscus or any lateral meniscus tear had a higher probability of improvement after arthroscopic surgery than did patients with other intraarticular pathology. There was no difference in the side effects between patients with AT and the control group. Despite acceptable scores in the methodological quality assessment, significant flaws could be found in all studies. These flaws include bad description of the exact surgical technique or poor control of postoperative use of non-steroidal anti-inflammatory drugs (NSAID).
Conclusion: Results of RCTs comparing AT with other treatment options were heterogeneous. AT in OA patients is not useless because there is evidence that a subgroup of patients with non-traumatic flap tears of the medial meniscus or patients with crystal arthropathy benefit from arthroscopy. This topic has a high relevance because several health insurances do not reimburse arthroscopy for patients with OA anymore. The results of these randomized studies, however, should be interpreted with care because in many studies, the use of other therapeutic variables such as pain killers or NSAIDs was not controlled or reported.
Level of Evidence: I.