Meniscal Repair Outcomes at >5 Years: A Systematic Review and Meta-Analysis

INTRODUCTION: Meniscal repair techniques (inside-out, all-inside, outside-in) continue to evolve. Assessment of meniscus repair outcomes at a minimum of 5 years postoperatively appears to best represent the true failure rates compared to 1 and 2-year timepoints. In the last decade, the literature on outcomes of meniscus repair has grown significantly. PURPOSE: To conduct a systematic review and meta-analysis to assess the rate of failure after meniscal repair at a minimum 5 years postoperatively. METHODS: We performed a systematic review of studies reporting the outcomes of meniscal repair at a minimum of 5 years postoperatively. A standardized search strategy was utilized with the assistance of a medical librarian. Abstracts and full-text articles were reviewed by two reviewers to identify studies assessing the clinical outcome of meniscus repair, which was most uniformly assessed by reoperation. Outcomes were assessed (when reported) relative to anterior cruciate ligament (ACL) status, sex, age, and postoperative rehabilitation protocol. Pooling of data and meta-analysis with a random-effects model were performed. RESULTS: A total of 28 studies of 1712 patients were included. In the last decade, 15 studies of 1168 patients have been reported, compared to 566 patients in 13 studies in the previous decade. The pooled failure rate of all devices was 22.2% (365/1712) and the failure rates of modern repairs was 17.5% (194/1128). Medial repairs were significantly more likely to fail compared to lateral repairs (26.4% [178/745] v. 13.0% [55/365], p=0.01). Failure rates varied from 16.9% for inside-out (78/501), 16.2% modern all-inside (66/396), 20.2% for outside-in (34/153), and 19.8% for open (22/109). First generation all-inside devices had a significantly higher failure rate (30.3%) compared to modern all-inside devices (16.2%) (p=0.01). There was no significant difference in failure rates between meniscal repair with concomitant ACL reconstruction (19.0%) and isolated meniscal repairs (19.6%, p=0.780). There was also no difference between post-operative rehabilitation protocols, sex, or age (all p>0.05). CONCLUSIONS: The outcomes of meniscal repair at a minimum 5 years postoperatively had an overall failure rate of 21.8%. Modern all-inside meniscus repair techniques appear to have improved the success rates compared to first-generation all-inside devices, and now appear similar to those of inside-out meniscus repair. Lateral repairs were significantly more likely to be successful compared to medial repairs. Finally, despite traditional teaching that ACL reconstruction improves rates of meniscus healing, across ˜700 patients, no difference in rates of healing were seen in ACL reconstruction compared to isolated meniscus repair.