Outside-In Continuous Suturing Is Superior to Interrupted Suturing for Repairing Peripheral Meniscus Lesions: An In Vitro Biomechanical Study Using a Porcine Model

Abstract

This in vitro biomechanical study using a porcine model compared peripheral longitudinal vertical meniscus lesion (PLVML) outside-in suture repair fixation strength using either interrupted or continuous "N" configuration No. 2-0 braided polyester sutures. Porcine lateral menisci were randomly assigned to group 1 (continuous) or group 2 (interrupted). Standardized PLVMLs were created in each specimen. Repaired specimens were placed in a specially designed clamp and loaded into a servohydraulic device. Specimens underwent preconditioning for 10 cycles (0.1 Hz, 5 to 20 N) and 500 submaximal loading cycles (0.5 Hz, 5 to 20 N), before load-to-failure testing (12.5 mm/s). A 30-second pause after preconditioning and after 10, 100, and 500 submaximal loading cycles enabled standardized digital photographs to be taken for gapping measurement determination. The failure mode was documented. Displacement and gapping during preconditioning and submaximal loading cycles did not differ between groups. Group 1 withstood a greater failure load (mean, 118.3 N; 95% confidence interval [CI], 97.2 to 139.4 N) than group 2 (mean, 63.7 N; 95% CI, 51.2 to 76.2 N) (P < .0001) and displacement during load-to-failure testing (mean, 5.3 mm; 95% CI, 4.2 to 6.5 mm) than group 2 (mean, 3.2 mm; 95% CI, 2.1 to 4.3 mm) (P = .005). Group 1 failed by suture breakage or suture pulling through tissue, whereas group 2 primarily failed by knot slippage (P < .0001). Group displacement and gapping differences were not observed after 500 submaximal loading cycles. PLVMLs repaired with a continuous N configuration, however, withstood greater load at failure and greater displacement before failure than repairs that used interrupted sutures. Continuous suture in an N configuration may improve PLVML repair fixation strength.