Clinical effectiveness and safety of intraarticular administration of a ^117mTin radiocolloid (Synovetin OA^TM) for treatment of early and intermediate grade osteoarthritis of the elbow in a dose finding study conducted in 44 dogs

Osteoarthritis of the elbow joint secondary to elbow dysplasia is common in dogs. Intraarticular radionuclide injection is thought to suppress both synovitis and inflammatory pain mediators in the joint which are not directly addressed by current treatments. This dose-finding investigation was a longitudinal, prospective, experimental parallel group, post-test study with repeated measures. Forty-four dogs, with low to intermediate-grade osteoarthritis, received a single injection into their most clinically affected elbow joint and were randomized into three treatment cohorts; 37 MBq, 64.75 MBq, or 92.5 MBq (normalized to the body surface area of a 22 kg dog) of ^117mSn radiocolloid. Dogs were assessed monthly by owners, using the canine Brief Pain Inventory (cBPI), and at 1, 3, 6, 9, and 12 months intervals by investigators. Positive responses to treatment were observed by both owners and clinicians in all dose groups with the medium dose group having the highest and most durable response rate based on cBPI scores. The results of this study support the use of ^117mSn radiocolloid as a primary treatment of osteoarthritis in low to intermediate-grade osteoarthritis of the canine elbow.