Meniscus repairs can be saved in the event of postoperative septic arthritis

PURPOSE: No systematic studies on optimal treatment of postoperative septic arthritis following arthroscopic meniscus repair are available. The purpose of this study was to retrospectively evaluate the fate of repaired menisci in cases of postoperative septic arthritis, with treatment for infection focused on arthroscopic irrigation and debridement (I&D) and intention to maintain the meniscus. METHODS: Data of two sports orthopedics centers of the last 10 years were pooled (approximately 25,000 arthroscopic procedures of the knee). All cases of septic arthritis following arthroscopic meniscus repair were identified. These cases were retrospectively evaluated with regard to clinical course and management, especially the number of necessary I&Ds, if eradication was achieved, and if the repaired meniscus was retained or a partial resection was necessary ('early failure'). Patients with initially maintained meniscus repairs were contacted if further meniscus surgery was performed in further follow-up ('late failure'). RESULTS: 20 patients with 23 repaired menisci were included. In 65% (13 cases), a concomitant anterior cruciate ligament reconstruction was performed. A mean of 2.0 ± 1.0 (1-4) arthroscopic I&Ds were performed in the treatment of septic arthritis. In two cases, additional open surgery was performed (after outside-in sutures). Eradication was achieved in all cases. Four repaired menisci (17.4%) showed loosened fixation or substantial degradation and were consequently partially resected within treatment for septic arthritis (early failures). The follow-up rate for the 19 initially maintained menisci was 94.7% after 3.0 ± 2.2 years (median 2.8, 0.4-7.8). Three of these underwent further partial resection (13.0%). Cumulative 3-year survival rate (Kaplan-Meier method) of all repairs was 70.7% (95% CI 50.3-91.1%), and for the subgroup of initially maintained menisci 85.6% (95% CI 67.0-100.0%), respectively. CONCLUSION: Septic arthritis following meniscus repair can be successfully treated with (sequential) arthroscopic I&Ds. There is a considerable rate of early failures, however, in a mid-term follow-up the failure rate of initially retained menisci is low and comparable to what we know from the literature for cases without infection. Therefore, it is generally recommended to try to save the repaired menisci in these cases. LEVEL OF EVIDENCE: IV, therapeutic case series.