The Biomechanical Performance of the Latest All-Inside Meniscal Repair Devices

Abstract

Purpose: To evaluate the biomechanical characteristics of recently introduced meniscal repair devices with a hand-tied, inside-out meniscal suture in a human meniscus model.

Methods: In detached adult human menisci, vertical longitudinal cuts were created 3 mm from the synovial-meniscal junction, simulating a bucket-handle meniscal tear. Each cut was repaired using a single device. Group 1 received a vertical mattress suture of No. 2-0 OrthoCord; group 2, TrueSpan device with PEEK (polyether ether ketone) anchors containing No. 2-0 OrthoCord suture; group 3, TrueSpan device with biodegradable poly-lactide-co-glycolide (PLGA) anchors containing No. 2-0 OrthoCord suture; group 4, Meniscal Cinch II device; group 5, AIR meniscal repair device; and group 6, FasT-Fix 360 device. All samples were preloaded at 5 N and cycled 200 times between 5 and 20 N. The specimens that survived cyclic loading were destructively tested at 12.5 mm/s. Endpoints included maximum load, displacement, stiffness, and failure mode.

Results: The mean failure loads were as follows: 95.8 N for OrthoCord suture, 87.1 N for TrueSpan with PEEK, 84.6 N for TrueSpan with PLGA, 48.6 N for Meniscal Cinch II, 72.3 N for AIR, and 68.1 N for FasT-Fix 360. Repairs performed with OrthoCord suture (P = .002) and both TrueSpan devices (P < .03) but not the FasT-Fix 360 device or AIR device were statistically significantly stronger than Meniscal Cinch II repairs. Mean cyclic displacement measured 1.1 mm for OrthoCord, 1.5 mm for TrueSpan with PEEK, 1.5 mm for TrueSpan with PLGA, 2.1 mm for Meniscal Cinch II, 1.1 mm for AIR, and 1.4 mm for FasT-Fix 360. The Meniscal Cinch II device showed more displacement than all other devices (P < .05). The FasT-Fix 360, AIR, and Meniscal Cinch II devices failed by anchor pullout from the peripheral meniscus. OrthoCord and both TrueSpan devices failed by suture pulling through the bucket-handle tissue.

Conclusions: OrthoCord suture is stronger than the AIR, FasT-Fix 360, and Meniscal Cinch II devices. The TrueSpan device with PEEK and TrueSpan device with PLGA are stronger than the Meniscal Cinch II device. The Meniscal Cinch II device failed during cyclic loading with greater cyclic displacement than the AIR device, FasT-Fix 360 device, OrthoCord, and TrueSpan device with PEEK. The Meniscal Cinch II, AIR, and FasT-Fix 360 devices failed by anchor pullout, whereas OrthoCord and both TrueSpan devices failed by suture pull-through.

Clinical relevance: Some newly introduced all-inside meniscal repair devices show inferior failure strength compared with earlier versions that might adversely impact clinical outcomes.