The Relationship between Limb Function and Radiographic Osteoarthrosis in Dogs with Stifle Osteoarthrosis

Objective - To evaluate the relationship between limb function and radiographic evidence of stifle osteoarthrosis (OA) in dogs. Study Design - The relationship between force platform data and radiographic OA score was evaluated on 2 separate days using regression analysis. Interday variation was also assessed. Animals - Forty-one dogs with visible lameness and radiographic evidence of stifle OA. Methods - Force platform data were collected at a velocity of 1.7 to 2.0 m/s for 5 trials on day 1 and day 8. Radiographs taken on day 1 were scored using a previously reported OA scoring system. Results - No significant relationship was found between force platform data and OA score. No significant differences were found between any day 1 and day 8 force platform values. Conclusions - Although radiographic evidence of stifle OA provides evidence of pathology, it does a poor job of representing limb function. In addition, the absence of significant differences between day 1 and day 8 values in this population of dogs supports use of only a single force platform evaluation before measuring a treatment effect. Clinical Relevance - The presence of OA in the stifle joint does not correlate with clinical function; radiographic outcome should be used cautiously as a predictor of clinical outcome.