Cartilage changes in dogs with surgically treated medial patellar luxations

The purpose of this study is to examine the stifle joint articular cartilag e changes in dogs with clinically significant patellar luxation and determi ne if this cartilage is significantly different from that of dogs without p atellar luxation. Osteochondral slices were obtained from dogs during reces sion sulcoplasty. Osteochondral sections were submitted for histological an alysis and histochemical staining. Articular cartilage was blindly evaluate d using a modified Mankin score. Cartilage histological scores were signifi cantly different between controls and dogs with patellar luxation. There wa s not any correlation between grade of luxation, age or length of clinical signs and histological score. Neither was there any significant difference between controls and dogs with patellar luxation, with respect to glycosami noglycan content, as estimated by Safranin-O staining. Most changes in the articular cartilage were seen in the top two zones and consisted of cell lo ss and minor surface fibrillation. Even with a statistically significant di fference, the changes in the cartilage were minor. In the authors' opinion, this study further supports the use of the recession sulcoplasty technique in treating patellar luxations in dogs. Surgical techniques that preserve hyaline cartilage should be recommended where possible.