Injection of Botulinum Toxin for Thumb Carpometacarpal Arthritis

The purpose of this clinical trial is to gather information on the safety and effectiveness of botulinum toxin injection (or Botox) in the treatment of thumb joint pain/arthritis. People with thumb joint pain or arthritis usually receive steroid injections to help with the pain. However, this medicine does not always work well and also carries known important side effects. There is currently no alternative to this injection medicine. This clinical trial seeks to investigate botulinum toxin as a possible alternative to steroid injection. The difference between Botox and steroid injections is that they are different medicines and work in different ways. Botox, as it is being used in this study, is not FDA-approved. It is therefore considered an investigational medicine.