Pelvic limb kinetic and kinematic analysis in Labrador Retrievers predisposed or at a low risk for cranial cruciate ligament disease.

Objective: To compare kinematics, net moments, powers, ground and joint reaction forces (GRF, JRF) across the hock, stifle and hip joints in Labrador Retrievers at low risk or predisposed to cranial cruciate ligament disease (CCLD). Study Design: Cross-sectional clinical study. Animals: Clinically normal Labradors predisposed (n = 11) or at low risk for CCLD (n = 9). Methods: Right pelvic limbs were classified as predisposed or not to CCLD using a predictive score equation based on combining tibial plateau angle (TPA) and femoral anteversion angle (FAA) measured on radiographs. Kinematic, GRF, and morphometric data were combined in an inverse dynamics approach to compute hock, stifle and hip kinematics, net moments, powers, and JRF while trotting. Results: The extensor moment of the hock joint was greater in predisposed limbs compared with nonpredisposed limbs (0.37 versus 0.28 Nm/kg). The power generated around the hock and stifle joints in predisposed limbs was increased (0.69 versus 0.44 W/kg for the hock, 1.59 versus 1.05 W/kg for the stifle). Trotting velocity, stance time, vertical and craniocaudal GRF and JRF did not differ between groups. Conclusions: Extensor moment at the hock was increased in predisposed limbs compared with nonpredisposed limbs. Predisposed limbs generated more energy than nonpredisposed limbs around the hock and stifle joints.