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.