Articular changes in patellar luxation afflicted canine stifle joints

Resumen

The ectopic placement of patella outside the trochlear groove leads to articular and peri-articular changes in the stifle joint, predisposing the joint to development of secondary osteoarthritis. This study focuses on the radiographic and gross macroscopic alterations (recorded during surgery) in 14 stifle joints of dogs affected with patellar luxation. A scoring to establish a correlation between the grade of luxation and the radiographic lesions in the stifle joints was done. The prevalence of articular cartilage erosions at different sub-divisions in affected cases was noted. The results report a significant correlation between the grades of luxation and the osteoarthritic changes visible on radiography. The radiographic changes included; shallow and flat trochlea, pseudo-trochlear groove formation, osteophytosis and erosion. Distal patella was the most common site for osteophyte formation with or without lytic changes in patellar luxation affected stifles. The intra-operative articular and peri-articular changes included deformed trochlea, mild to moderate osteophytosis and articular cartilage erosion in 57% cases, of which distal patellar articular surface and lateral trochlea were the most commonly affected. The study recommends use of radiography as the prognostic indicator for stifle joint health in patellar luxation affected dogs and its early surgical management.