Comparison of Tibial Plateau Angles in Normal and Cranial Cruciate Deficient Stifles of Labrador Retrievers

OBJECTIVE: To investigate tibial plateau angles (TPA) in normal and cranial cruciate ligament (CCL) deficient stifles of Labrador retrievers. STUDY DESIGN: Prospective clinical study. ANIMALS: Eighty-one client-owned purebred Labrador retrievers. METHODS: Lateral radiographs of the tibia were obtained from 2 groups of dogs. Group I (42 dogs) had CCL rupture diagnosed by arthrotomy or arthroscopy. Group II (39 dogs) had no history of orthopedic problems, no radiographic evidence of CCL rupture, and dogs were >8 years of age. The tibial axis and the tibial plateau were determined on the radiographs, and the TPA was measured using image measurement software. The TPA measurement results of groups I and II were compared. RESULTS: Group I (CCL rupture) had a mean TPA (+/-SD) of 23.5 (+/-3.1) degrees, and group II (normal) had a mean TPA (+/-SD) of 23.6 (+/-3.5) degrees. With a P value of.97, no statistical difference was detected between the 2 groups. CONCLUSIONS: No correlation between the magnitude of TPA and CCL rupture was identified in this group of Labrador retrievers. CLINICAL RELEVANCE: In Labrador retrievers, TPA should not be used as a predictor of CCL rupture.