Double-Cinch and Modified Mason-Allen Meniscal Root Repairs Demonstrate Comparable Time-Zero Biomechanical Performance with Cortical Button or Knotless Anchor Fixation: A Controlled Porcine Study

PURPOSE: The optimal suture configuration and tibial fixation method for posterior meniscal root repair remain undefined. This study aimed to compare the time-zero biomechanical behavior of double-cinch and modified Mason-Allen repair constructs combined with cortical plate or knotless suture anchor fixation in a controlled porcine model. METHODS: Twenty-eight porcine medial menisci were randomly allocated to four repair constructs (n = 7 per group): double cinch with cortical button fixation (CINCH), double cinch with knotless anchor fixation (CINCH-A), modified Mason-Allen with cortical button fixation (MA), and modified Mason-Allen with knotless anchor fixation (MA-A). Following standardized repair, specimens underwent preconditioning and load-to-failure testing using a universal testing machine. Stiffness, yield load, maximum load, ultimate load, and displacement were analyzed using non-parametric statistical methods. RESULTS: All specimens failed by progressive elongation at the meniscus-suture interface. Median stiffness ranged from 14.0 to 26.5 N/mm, yield load from 36.7 to 47.5 N, and ultimate load from 135.0 to 167.0 N across constructs. No statistically significant differences were identified among groups for stiffness (p = 0.25), yield load (p = 0.12), maximum load (p = 0.11), ultimate load (p = 0.14), displacement at maximum load (p = 0.33), or displacement at ultimate load (p = 0.18). Grouping constructs by suture configuration or fixation method did not alter these findings after adjustment for multiple comparisons. CONCLUSION: Double-cinch and modified Mason-Allen meniscal root repair constructs demonstrated comparable time-zero biomechanical behavior when combined with either cortical button or knotless anchor fixation. Because all specimens failed at the meniscus-suture interface, the tissue-suture interaction appears to be the primary determinant of initial construct failure under load-to-failure testing. LEVEL OF EVIDENCE: Not applicable.