RecruitingPhase 2Drug trialRandomized Placebo Controlled Study of Triamcinolone Acetonide Extended Release Injection for Thumb (CMC) OsteoarthritisThe goal of this study is to investigate if a timed release steroid injection may be beneficial in treating carpometacarpal (CMC) joint (thumb) osteoarthritis. The main questions to be answered are: 1. does the steroid injection substantially reduce pain in the thumb 2. does the steroid injection help to increase thumb function Participants will be asked to undergo a thumb CMC joint injection and to attend follow up visits to assess pain and thumb function.