Arthritis at the thumb base
Thumb carpometacarpal (CMC) arthritis affects the joint where the thumb meets the wrist. This joint allows the thumb to reach across the palm and position itself for pinch. Changes in cartilage and joint support can cause pain during use. The surrounding tissues may also become irritated as the mechanics of the joint change.
Opening a jar or turning a key can expose the problem. These tasks place force through the thumb base, even when the object feels light. Pain can develop gradually and may fluctuate with activity. The treatment decision depends on the symptoms and the work you need your hand to perform, alongside the findings on examination and imaging.
Pain, weakness, and changes in shape
Pain at the thumb base can extend into the fleshy part of the palm. Pinching clothing fasteners or holding a phone can become uncomfortable. A person may notice reduced grip confidence because pressure through the joint hurts. Swelling or a prominent bump can develop near the base of the thumb.
Thumb posture can change as joint support changes. The next joint toward the tip may bend backward during pinch, altering how force travels through the thumb. Tell the clinician which motions are painful and whether numbness, clicking, or wrist pain is also present. These additional symptoms can identify a separate problem that needs attention alongside the arthritis.
Examination and X-rays
The examination identifies the painful joint and checks how the thumb moves under load. The clinician assesses tenderness, stability, pinch posture, and nearby tendons. Pressure and rotation at the CMC joint may reproduce symptoms. Sensation and the other joints of the hand are also relevant to the assessment.
X-rays show joint space, bone position, and changes such as bone spurs. The amount of change on an X-ray can differ from the amount of pain a person experiences. Treatment therefore reflects your symptoms and function as well as the images. Bring previous studies and describe the tasks you have changed or given up because of pain.
Supports and changes to hand use
A thumb support can reduce painful movement while allowing the fingers to work. A hand therapist can help choose or make a support and check the fit. Wider handles, jar-opening aids, and changes in grip can reduce the force needed for household tasks. The aim is to make daily hand use comfortable and sustainable.
Medication or a corticosteroid injection may be considered for pain. Medication choice depends on your medical history, kidney function, stomach problems, and other medicines. An injection can provide symptom relief, but it does not restore lost cartilage. Discuss the expected role of each option and how you will judge whether it is helping with the activities that matter to you.
Surgery for persistent symptoms
Surgery may be an option when pain continues to limit daily activities despite nonsurgical care. Procedures can include removal of the trapezium, a wrist bone at the thumb base, with a selected method to support the thumb. Fusion or other reconstructive approaches may suit particular circumstances. The surgeon considers joint involvement, stability, and your functional demands.
Each operation has tradeoffs involving motion, strength, protection, and rehabilitation. Risks include infection, nerve irritation, stiffness, persistent pain, and problems with the reconstruction. Ask which procedure is proposed and why it fits your examination. Discuss the amount of thumb use required at work and at home so recovery arrangements can be made before treatment.
Recovery and protection of the thumb
Recovery after reconstruction includes a period of protection followed by guided motion and strengthening. A splint and hand therapy may be part of the plan. Progress depends on tissue healing and the specific procedure. Pinch and grip activities need to follow the restrictions given by the treating team.
Planning practical help can make recovery manageable. Clothing fasteners, food preparation, and opening medication containers may require adaptations while the thumb is protected. Ask when you can drive and return to your usual tasks. Sudden redness, warmth, or marked swelling requires assessment, particularly after an injection or surgery. For ongoing arthritis symptoms, tracking which tasks hurt provides a useful way to evaluate whether treatment is meeting your needs.
A useful follow-up discussion compares specific tasks before and after treatment. Describe whether turning a key, fastening clothing, and preparing a meal have become comfortable enough for your needs.
Further reading: AAOS: Arthritis of the thumb