Cyclic Test Comparison of All-Inside Device and Inside-Out Sutures for Radial Meniscus Lesion Repair: An In Vitro Porcine Model Study

Abstract

To compare biomechanical fixation and gapping characteristics of a new all-inside meniscus repair method for radial meniscus lesion repair versus conventional inside-out suture repair under submaximal cyclic loading and load-to-failure test conditions. Fresh-frozen porcine tibiae with attached lateral menisci and joint capsules were harvested and stored for 48 hours at -20°C. After thawing for 12 hours, equivalent-size healthy specimens were randomly assigned to 2 groups of 8 specimens each. Standardized radial lesions were repaired with the Sequent device (ConMed Linvatec, Largo, FL) (group 1) or conventional inside-out suturing with No. 2-0 braided polyester suture (group 2). Repaired specimens were placed in custom clamps and mounted on a servohydraulic device. After a 2-N preload, specimens were cycled from 5 to 20 N (0.1 Hz), before undergoing 1,000 submaximal loading cycles between 5 and 20 N (0.5 Hz). A 40-second delay at 100, 500, and 1,000 cycles enabled digital photographs to be taken for gapping measurement determination. Specimens then underwent load-to-failure testing (12.5 mm/s). Fixation failure mode was documented. Group displacement did not differ after 1, 100, 500, and 1,000 submaximal loading cycles. Group peak gapping did not differ at 100, 500, and 1,000 submaximal loading cycles. Load at failure and displacement and stiffness during load-to-failure testing did not differ between groups. During load-to-failure testing, all-inside specimens failed by implant dislodgement from the meniscus periphery whereas the inside-out repaired specimens failed by suture rupture. Under controlled in vitro biomechanical test conditions, the all-inside device provided radial meniscus lesion fixation that was comparable, but not superior, to conventional inside-out suturing. The all-inside radial lateral meniscus lesion repair method may provide comparable fixation to conventional inside-out suturing without the need for additional incisions and their associated neurovascular injury risks.