Cyclic testing of 3 all-inside meniscal repair devices: a biomechanical analysis.

Abstract

Despite the growing popularity of all-inside meniscal repair devices, concerns remain about their fixation strength. It is also unclear which of these devices have the most ideal biomechanical properties. To compare the biomechanical properties of 3 all-inside meniscal repair devices: the Meniscal Cinch, Ultra FAST-FIX, and MaxFire. Controlled laboratory study. Twenty-seven human cadaveric menisci (3 groups of 9) were repaired using 3 different meniscal repair devices. The repaired menisci were then subjected to cyclic loading and load-to-failure testing. Gap formation and ultimate load to failure were measured. Six of the devices failed during cyclic testing, 4 in the MaxFire group (44%), 1 in the Ultra FAST-FIX group (11%), and 1 in the Meniscal Cinch group (11%). After 1 cycle, there was a trend toward larger gap formation in the MaxFire group (3.65 mm) compared with the Meniscal Cinch group (2.12 mm, P = .05). After 100 cycles, group differences were found in gap formation (P = .03), with the MaxFire group exhibiting greater displacement (6.70 mm) than the Ultra FAST-FIX group (3.59 mm). After 500 cycles, group differences in gap formation (Meniscal Cinch, 5.94; Ultra FAST-FIX, 4.74 mm; Max Fire, 7.19 mm) did not reach statistical significance (P = .20). A trend was found toward higher ultimate load to failure in the Ultra FAST-FIX (86.1 N) and Meniscal Cinch (85.3 N) groups compared with the MaxFire group (64.5 N, P = .06). Stiffness was also higher in the Ultra FAST-FIX (25.2 N/mm) and Meniscal Cinch (25.5 N/mm) groups than the MaxFire group (16.3 N/mm, P = .02). The Meniscal Cinch and Ultra FAST-FIX devices have more desirable biomechanical properties than the MaxFire as demonstrated by higher stiffness and a lower failure rate during cyclic testing. The Meniscal Cinch and Ultra FAST-FIX devices may be more desirable implants for use during all-inside meniscal repair as they have superior biomechanical properties when compared with the MaxFire device.