Ex Vivo Evaluation of Intra-Articular Cranial Cruciate Ligament Repair Using an Ultra-High Molecular Weight Polyethylene Graft in the Cats

Abstract This aim of this study was to determine feline stifle joint stability and muscle force ratios after cranial cruciate ligament transection and intra-articular reconstruction, and assess the feasibility of this reconstruction in cats. Ten feline hindlimbs were tested in an axial limb press with 30% body weight load. Femoral angles were set to 60 degrees, and stifle and hock angles to 120 degrees. The cranial cruciate ligament was transected, and testing was repeated. Intra-articular reconstruction was performed using a 16-strand ultra-high molecular weight polyethylene graft and four 3 mm interference screws. Friedman's repeated-measures analysis of variance compared angles, forces, and tibial translation. Tibial translation increased significantly after cranial cruciate ligament transection (p = 0.02) but did not differ from intact joints post-reconstruction (p = 0.5). Forces (p = 0.72, p = 0.74) and bone/joint angles (p = 0.12) did not differ across test situations. Mean quadriceps force was twice the gastrocnemius force. Measurement repeatability was good, with a within-subject standard deviation for distance at 0.4 mm and for angles at 0.4 to 1.1 degrees. Limb press positioning was consistent and repeatable, and muscle forces approached in vivo values. Intra-articular reconstruction restored joint stability under static load and appeared feasible for use in cats.