Evaluation of a method for experimental induction of osteoarthritis of thehip joints in dogs

Objective-To evaluate a method for experimental induction of osteoarthritis in the hip joints of dogs. Animals-12 mixed-breed dogs. Procedure-A unilateral triple pelvic osteotomy was performed. In 6 dogs, th e iliac osteotomy was repaired with 45 degrees of internal rotation, reduci ng coverage of the femoral head by the acetabulum. In the other 6 dogs, the fragments were repaired in anatomic alignment. Radiography, force plate ev aluations, and subjective lameness evaluations were performed before and af ter surgery. Dogs were euthanatized 7 months after surgery, and samples of cartilage and joint capsule were examined histologically. Results-Subjective lameness scores, radiographic appearance of the hip join ts, and Norberg angles were not significantly different between groups; how ever, force plate evaluations did reveal significant differences in vertica l ground reaction forces. Femoral head coverage was significantly decreased with rotation of the acetabulum. Mild inflammatory changes were discernibl e in the joint capsule and articular cartilage of some dogs in both groups. Conclusions and Clinical Relevance-Results suggest that 45 degrees internal rotation of the acetabulum does not consistently induce biologically impor tant osteoarthritic changes in the hip joints of dogs.