Basal joint arthritis or thumb carpometacarpal arthritis (CMC arthritis), is a form of wear and tear arthritis that occurs at the base of the thumb between the 1st metacarpal and the trapezium. Many people experience pain in the wrist and base of the thumb that feels like it is in the palm of the hand. Typically activity and use make the pain worse. After time, the joint and supporting ligaments will become eroded and deformity will occur.
Like all osteoarthritis, this is a progressive disease and nothing actually stops its progression, except for surgery. However, there are many different treatments both surgical and non-surgical that can be tailored to a patient’s specific degree of pain.
Typically, patient’s will come in with a series of complaints that are typical of basal joint arthritis including, thumb, wrist and hand pain, or a Z deformity of the thumb.
Physical exam and X-rays are also used to confirm the diagnosis.
Typically patients will start with a steroid injection into the joint. Depending on the severity of arthritis a splint may be used to stabilize the joint and decrease pain. Ultimately surgery is the only definitive solution for the problem.
My preferred method of reconstruction is a trapeziectomy with ligament reconstruction and tendon interposition. Simply put, the trapezium bone is removed and one of the tendons in your wrist is used to reconstruct the suspensory ligaments of the thumb and create a bumper for the thumb metacarpal bone to rest on. This is one of the most well studied and reliable surgeries offered in hand surgery and provides great outcomes for patients who are appropriately selected.
Surgery takes typically 1 hour. After surgery you will follow up with a certified hand therapist for the creation of a thermoplastic splint. You will wear this splint for 4 weeks. Immediately post op the therapist will start range of motion of all thumb and wrist joints EXCEPT the basal joint or thumb CMC joint. At 4 weeks the therapist will initiate thumb CMC joint motion. At 6 weeks the therapist will initiate strengthening.
Patients do very well with this surgery and it has been widely validated as the most consistent and durable repair for regaining full use of the thumb, including, range of motion, pain relief, pinch strength, and a usable thumb.