Articular cartilage lesions associated with complete lateral meniscal tears in the dog

OBJECTIVE: To describe articular cartilage (AC) lesions associated with complete lateral meniscal tears in dogs. STUDY DESIGN: Observational series. ANIMALS: Seventeen dogs with arthroscopic evidence of a complete lateral meniscal tear and associated AC lesions. METHODS: Medical records of dogs with arthroscopic evidence of complete lateral meniscal tear and associated AC lesions between March 2006 and December 2017 were examined for arthroscopic findings. RESULTS: The cranial cruciate ligament (CrCL) was intact in 11 of 17 dogs, partially ruptured but competent in 4 of 17 dogs, and completely ruptured in 2 of 17 dogs. All dogs had grossly normal caudal cruciate ligament, medial meniscus, and AC of the medial compartment. In each dog, a complete radial tear of the caudal body of the lateral meniscus was associated with degenerative osteoarthritis (OA) of the lateral compartment of the stifle. The Outerbridge score of the lateral tibial condyle and lateral femoral condyle was 5 of 5 in 15 dogs, 3 of 5 in 1 dog, and 4 of 5 in 1 dog. CONCLUSION: Dogs with complete tears of the lateral meniscus developed degenerative OA of the lateral compartment of the stifle leading to AC loss and clinical dysfunction. CLINICAL SIGNIFICANCE: Complete lateral meniscal tears may occur as isolated injuries in dogs with a functional CrCL.