Incidence of motion loss of the stifle joint in dogs with naturally occurring cranial cruciate ligament rupture surgically treated with tibial plateau leveling osteotomy: longitudinal clinical study of 412 cases.

OBJECTIVE: To report the incidence of loss of stifle extension or flexion and its relationship with clinical lameness after tibial plateau leveling osteotomy (TPLO) for treatment of cranial cruciate ligament (CCL) rupture. STUDY
DESIGN: Longitudinal study. ANIMALS: Dogs (n=280) with CCL rupture (n=412).
METHODS: TPLO was performed without meniscal release or arthrotomy. Angles of extension and flexion of the stifle were measured by goniometry to determine range of motion. Based upon motion loss, stifles were divided in 3 groups: no loss of extension or flexion (n=322), <10 degrees loss of extension or flexion (n=78), > or =10 degrees loss of extension or flexion (n=12).
RESULTS: Loss of extension or flexion > or =10 degrees was associated with significantly (P=.001) higher clinical lameness scores in comparison with no loss, or loss of extension or flexion <10 degrees. Osteoarthrosis in the cranial femorotibial joint was significantly correlated (P<.005, r(2)=0.55) with loss of extension. Loss of extension > or =10 degrees was less tolerable and less amenable to physical rehabilitation than flexion loss.
CONCLUSIONS: Loss of extension or flexion > or =10 degrees was responsible for higher clinical lameness scores. Osteoarthrosis in the cranial femorotibial joint led to extension loss. CLINICAL RELEVANCE: Loss of extension or flexion should be assessed in dogs with persistent clinical lameness after TPLO so that early intervention can occur. Our study provides guidelines to define clinically relevant loss of extension or flexion of stifle joint after TPLO.