Failure rate of isolated medial meniscus repair in the stable knee: Systematic review and meta-analysis.

Purpose: The present meta-analysis aims to determine the outcomes and failure rates for medial meniscus repairs in patients with stable knees.

Methods: A literature search was conducted using PubMed and Scopus with the terms '(medial meniscus OR medial meniscal) AND (repair)'. The search strategy was based on the PRISMA (Preferred Reporting Items for Systematic Meta-Analyses) protocol and included 93 articles assessed for eligibility. The search criteria were limited to studies reporting outcomes and failure rates. The exclusion criteria included languages other than English, biomechanical studies, letters to editors, non-full text, review articles, meta-analyses and case reports.

Results: In total, 10 studies with 595 patients were included. Degenerative tears or studies reporting meniscus repair outcomes on root repairs, revision or primary anterior cruciate ligament reconstruction, discoid menisci or ramp lesions were excluded. All studies included revision surgery and/or clinical symptoms as failure definitions. The overall medial meniscal repair failure rate was 26% with a 95% confidence interval (CI) [15%-37%]. The mean time to failure from isolated medial meniscus repair surgery was 27.7 months with 95% CI [18.5-36.9 months]. The postoperative Lysholm and IKDC scores were reported in three articles. At the final follow-up, the mean postoperative Lysholm and IKDC scores were 92.3 with 95% CI [84.5-100] and 88.6 with 95% CI [83.5-93.8], respectively.

Conclusion: The current meta-analysis revealed an overall failure rate of 26% in the case of medial meniscus repair in a stable knee. For these reasons, the patient should be aware of the substantial risk of revision surgery (one out of four cases). Medial meniscus repair in a stable knee yielded good clinical results.

Level of evidence: II.