Base of Thumb Arthritis
Arthritis within the joint at the base of the thumb can be caused by many factors such as genetics, age or occupation. It is common in the fifth and sixth decades of life and can be aggravated or triggered by typical gripping and pinch actions. The joint in the base of the thumb is commonly known as the carpometacarpal (CMC) joint.
Prolonged overuse of the joint can contribute to cartilage or ligament changes within the joint. People with loose (or lax) ligaments often pinch in a way that can cause further stress to the ligaments and joint, resulting in pain and irritation.
This can be temporary or longstanding. Long term base of thumb arthritis can cause moderate dysfunction resulting in changes to the thumb’s strength and appearance.
How Can Our Hand Therapists Help?
Common symptoms of arthritis such as pain, weakness and joint positional changes can be well controlled through strategies to restore the thumb’s joint stability. A hand therapist can assist with strategies like pain management, joint strengthening or simple preventative ideas to support continued long-term use of the hand. We may also match your thumb shape and biomechanics to relevant resting and functional supports and splinting options, helping joint stability. This can include custom made supports (our specialty).
The force going through the tip of the thumb is only a tenth of what goes through at the base of the thumb during pinching tasks. For example, two kilograms of pressure at the thumb tip, results in over 20 kilograms of pressure moving through the base of the thumb. It helps to explain why activities of daily living can be so painful on these joints.
Arthritis to the base of the thumb is most likely to occur in the dominant hand, occurring in 60-65% of presenting cases (Haase & Chung, 2011).
Haase, S. C., & Chung, K. C. (2011). An evidence-based approach to treating thumb carpometacarpal joint arthritis. Plastic and Reconstructive Surgery, 127(2), 918. Doi: 10.1097/PRS.0b013e3182046901
Solutions to Try
While these are general examples, our hand therapists will help match solutions best suited to your condition and specific needs.