Arthritis at the base of the thumb is a common condition that mostly affects postmenopausal women. This condition can cause pain, swelling, and loss of motion with serious consequences. The symptoms from this type of arthritis can prevent simple, everyday tasks. Picking up a cup of coffee, fastening buttons, or holding a book can be agonizing or even impossible. Some people are unable to continue working at their jobs. What can be done about this?
When pain, weakness, and loss of motion cause difficulties, surgery may be necessary. The joint in question is between the base of the thumb and the trapezoid bone, the small wrist bone next to the thumb. Together these two bones form the trapeziometacarpal joint (TM). Different surgical methods are used to repair or restore this joint.
One method of fixing the TM joint is to fuse the bones together, a procedure called arthrodesis. Wire and bone chips taken from the patient’s hip are used to hold the bones together. A second method is called interposition arthroplasty. The joint surfaces of the TM joint are shaved off, creating a space between the joint. The doctor takes a strip of tendon from a nearby muscle, rolls it into a ball, and places it into the joint space. The tendon ball acts as a “spacer” to keep the sore parts of the joint from rubbing together.
A study compared 24 arthroplasties to 32 joint arthrodeses to determine which operation had the best results.
Interposition arthroplasty was clearly the winner! Compared to fusing the joint, using a spacer between the joint brought less pain, fewer problems with changes in temperature, and better thumb and hand function. There were also fewer complications after surgery, fewer reoperations, and a shorter time in a cast after surgery. The only advantage of the joint arthrodesis was that more people returned to their jobs or daily activities. Researchers think this was because more people in the arthrodesis group were still working before surgery.
Although both groups with arthritis of the thumb benefited from surgery, using a spacer has many more advantages over fusing the joint. There are still some cases where fusion could be used, such as when movement is good in the rest of the thumb. Overall, however, joint arthroplasty is the preferred treatment for disabling arthritis at the base of the thumb.