Outside-in continuous suturing is superior to interrupted suturing for repairing peripheral meniscus lesions: an in vitro biomechanical study using a porcine model.

PURPOSE: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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. CLINICAL RELEVANCE: Continuous suture in an N configuration may improve PLVML repair fixation strength.

Indications for 2-incision anterior cruciate ligament surgery.

Two-incision anterior cruciate ligament reconstruction uses an outside-in femoral drilling technique. Advantages include anatomic femoral tunnel placement and increased versatility with regard to graft position and fixation in the femoral tunnel or distal femur. The authors believe that transtibial femoral tunnel drilling is inferior because of nonanatomic femoral tunnel placement and the requirement of the posterior footprint placement of the tibial tunnel. Indications for outside-in femoral drilling include revision anterior cruciate ligament reconstruction, drilling an all-epiphyseal tunnel in skeletally immature patients, long bone-patellar tendon-bone autografts when using more than 45 mm of tendon, and cases in which the leg cannot be hyperflexed for accessory anteromedial portal drilling.