All-inside repair is an effective treatment for medial meniscus posterior root tears: a systematic review and meta-analysis of biomechanical and clinical evidence.
BACKGROUND: Medial meniscus posterior root tears (MMPRTs) reproduce the biomechanics of subtotal meniscectomy. Repair is favored, but the role of all-inside repair (AR) remains unclear relative to transtibial pull-out (TP). This study aimed to review the biomechanical and clinical evidence on AR for MMPRTs. METHODS: A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and registered in the International Prospective Register of Systematic Reviews (PROSPERO). MEDLINE, Embase, Scopus, and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched. Outcomes included patient-reported outcome measures (PROMs), magnetic resonance imaging (MRI), and biomechanical performance. When available, random-effects meta-analysis was performed. RESULTS: Thirteen studies were included. AR restored contact mechanics and showed load to failure comparable to TP, with lower stiffness. Meta-analysis showed lower conversion to total knee arthroplasty with AR versus non-repair (RR 0.18, 95% CI 0.05-0.58), and no significant PROM differences between AR and TP. CONCLUSIONS: AR showed favorable biomechanical properties and improved outcomes versus non-repair. Compared with TP, no significant clinical differences were observed. AR may represent a reasonable option in selected scenarios.