The surgical anatomy of the stifle joint in sheep

Objective-To provide a detailed description of the surgical anatomy of the stifle joint in sheep. Study Design-The results from analysis of cadaveric dissections (14 stifle joints) and stifle radiographs (8 sets of mediolateral and craniocaudal radiographs) are presented. Animals-Skeletally mature ewes of mixed breeds. Conclusions-Although the anatomy of the vine stifle joint is similar to that of the human knee joint, a number of unique features were identified. These included the presence of the tendon of the m. extensor digitorum longus on the craniolateral aspect of the stifle joint, the absence of a cranial meniscofemoral ligament (ligament of Humphrey) in the caudal joint space, and attachment of the patellar tendon to the cranial pole of the patella (rather than to the distal pole, as in humans). The implications of these differences are discussed with reference to the suitability of the ovine stifle as a surgical model for the human knee joint. (C) Copyright 1998 by The American College of Veterinary Surgeons.