Yizhong Peng, Wenbo Yang, Yi Li, Chunqing Meng, Hong Wang, Wei Huang
PURPOSE: To evaluate the biomechanical performance of the sewing machine-like suture (SMS) technique against three established techniques (two cinch-loop (TCL), modified Mason-Allen (MMA), and double Mason-Allen (DMA)) for transtibial pull-out repair of posterior medial meniscal root tear (PMMRT) in a porcine model. METHODS: Forty fresh-frozen porcine medial menisci (20-25 weeks old, no macroscopic degeneration) were randomly assigned to 4 groups for repair using TCL, MMA, DMA, or SMS. All repairs used nonabsorbable braided suture and an 18G needle. Biomechanical testing included cyclic loading to measure displacement and load-to-failure testing to assess ultimate failure load, yield load, stiffness, and failure displacement. RESULTS: SMS achieved the highest ultimate failure load (358.0 ± 34.9 N) versus DMA (308.57 ± 52.36 N, P = .0292) and TCL (227.95 ± 42.36 N, P < .0001) and the highest yield load (299.15 ± 12.2 N) versus TCL (150.0 ± 31.6 N, P < .0001) and MMA (274.21 ± 15.7 N, P = .0113). DMA showed the smallest displacement at 100 cycles (0.21 ± 0.05 mm) and 500 cycles (0.34 ± 0.06 mm). MMA had the least displacement at 1000 cycles (1.01 ± 0.13 mm) and failure (7.86 ± 0.79 mm). TCL exhibited the largest displacement at 1000 cycles (2.44 ± 0.57 mm) and lowest strength. CONCLUSIONS: The SMS technique exhibited the higher load resistance by integrating multipoint fixation through a single-suture mechanism, while DMA provides the best cyclic stability. Both techniques surpass conventional methods like TCL, which showed the largest displacement. CLINICAL RELEVANCE: This biomechanical study provides evidence to guide suture technique selection for posterior medial meniscal root repair. The SMS technique, with its superior load resistance approaching the physiological range of the native root, may be particularly advantageous in clinical scenarios demanding high fixation strength.