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.

Kinetic and kinematic analysis of the right hind limb during trotting on a treadmill in Labrador Retrievers presumed predisposed or not predisposed to cranial cruciate ligament disease.

OBJECTIVE: To identify gait characteristics during trotting on a treadmill in nonlame Labrador Retrievers presumed predisposed or not predisposed to cranial cruciate ligament disease (CCLD). ANIMALS: Clinically normal Labrador Retrievers presumed predisposed (n = 10) or not predisposed (7) to CCLD. PROCEDURES: The right hind limb of each dog was classified by use of a predictive score equation that combined tibial plateau angle and femoral anteversion angle as presumed predisposed (high score [> -1.5]) or not predisposed (low score [≤ -1.5]) to CCLD. Tarsal joint, stifle joint, and hip joint kinematics, net moments, and powers were computed. RESULTS: The stifle joint was held at a greater degree of flexion in limbs presumed predisposed to CCLD (130.9° vs 139.3°). More power was generated by muscles acting on the stifle joint in the early stance phase of limbs presumed to be predisposed to CCLD (2.93 vs 1.64 W/kg). The tarsal joint did not reach the same degree of extension in limbs presumed predisposed to CCLD, compared with that in limbs presumed not predisposed to CCLD (179.0° vs 161.0°). Velocity, stance time, vertical and craniocaudal forces, angular velocities, and net joint muscle moments did not differ between groups. CONCLUSIONS AND CLINICAL RELEVANCE: Gait mechanics of dogs with high (> -1.5) and low (≤ -1.5) tibial plateau angle and femoral anteversion angle scores were characterized on a treadmill, which may help in the identification of dogs predisposed to CCLD.