Minimal Clinically Important Differences for a Weight Distribution Platform in Dogs with Osteoarthritis

In this retrospective study to determine the optimal method of evaluating static weight-bearing distribution to assess response to treatment in dogs with osteoarthritis using a weight distribution platform, data from the Clinica Veterinaria de Caes (Portuguese Republican National Guard) clinical records were extracted. At baseline and at 15 days post-treatment, follow-up data from 80 dogs treated for bilateral hip osteoarthritis were categorized based on an anchor question. Estimates of minimal clinically important differences were calculated with distribution-based and anchor-based methods for deviation from normal weight-bearing and a symmetry index (SI). For deviation, the anchor-based methods provided a range from -0.3 to -3.1, and the distribution-based methods from 0.16 to 0.29. For SI, the anchor-based methods provided a range from -10.0 to -23.9, and the distribution-based methods from 1.31 to 2.88. Receiver operator characteristic curves provided areas under the curve >0.7, indicating an acceptable cut-off point. We presented estimates of -1 for deviation and -10 for SI in dogs with OA. These estimates can be used for research and patient monitoring. Future studies should include OA from other joints and animals from a broader clinical context.