Morphometric characteristics of the pelvic limbs of Labrador Retrievers with and without cranial cruciate ligament deficiency.

OBJECTIVE-To evaluate skeletal characteristics of pelvic limbs with and without cranial cruciate ligament (CCL) deficiency in Labrador Retrievers. ANIMALS-30 adult purebred Labrador Retrievers. PROCEDURES-Pelvic limbs (n = 28) of 14 dogs without CCL deficiency were classified as control limbs, whereas the limbs of 16 dogs with CCL deficiency were considered affected by (18 limbs) or predisposed to (10 contralateral limbs of dogs with 1 affected limb) CCL deficiency. Skeletal characteristics were evaluated via physical examination, radiography, and computed tomography. Radiographic and computed tomographic variables were compared among limb groups by use of a mixed-model ANOVA. RESULTS-The tibial plateau slope was steeper in CCL-deficient limbs but not in predisposed limbs, compared with the slope in control limbs. The angle between diaphyseal and proximal tibial axes was increased in both CCL-deficient and predisposed limbs. The relative width of the proximal portion of the tibia and the inclination of the patellar ligament did not differ among limb groups. The overall and distal femoral anteversion angles were greater in CCL-deficient and predisposed limbs, whereas the femoral condyle trochanteric angle was decreased in those limb groups, compared with findings in control limbs. CONCLUSIONS AND CLINICAL RELEVANCE-Cranial angulation of the proximal portion of the tibia, excessive steepness of the tibial plateau, and distal femoral torsion appeared more likely to be associated with CCL deficiency than femoral angulation, tibial torsion, intercondylar notch stenosis, and increased inclination of the patellar ligament.