The aim of surgery for base of thumb arthritis is to provide pain relief.
In younger patients, with arthritis restricted to the joint at the base of the metacarpal, a prosthesis can sometimes be inserted into the joint to provide a smooth replacement joint surface for the bone to articulate against. This is a relatively new treatment option and early results seem to be quite encouraging. In cases of more advanced arthritis however the traditional treatment for base of thumb arthritis has been to exercise the trapezium.
An excision of the trapezium is a relatively reliable way of improving patient’s discomfort although the recovery takes quite some time.
The surgery is usually performed under general anaesthetic. A tourniquet is applied to the arm to prevent any blood flow in or out of the arm.
An incision is then made along the outer border of the thumb and the joint at the base of the thumb is opened. The soft tissues are gently dissected away from the trapezium and the complete trapezium is removed. This takes away the problem with the worn out joint surfaces rubbing against each other and causing pain.
Removing the trapezium leaves a void. This is usually filled with a strip of tendon which is harvested from the forearm (half of one of the flexor tendons from the wrist is used).
A drill hole is made in the base of the metacarpal and the tendon is passed through this and used to recreate supporting ligaments around the base of the thumb to provide stability.
The remaining length of the tendon is then rolled up and placed in the void where the trapezium had been removed from. The capsule around the joint is closed and the skin is sutured.
Following surgery, the thumb is kept immobilised in a splint for the first six weeks.
Most patients will stay in hospital overnight following the surgery with their hand elevated. At the end of the operation, a large volume of local anaesthetic is injected to provide good pain relief in the first 12 hours. Patients may require painkillers for the first week or two after surgery.
Patients are reviewed at two weeks following surgery to have their sutures removed. There may be some swelling in the hand that stage.
By six weeks, most patients are able to start gradually moving their thumb and doing some lightweight activities. it usually takes up to 3 months before patients are able to increase their activities.
Although the recovery can seem long, most patients are very happy with the improvement in pain. Some patients will still notice a reduction in grip strength and pinch strength but these activities are usually much more comfortable after the surgery.