Base of thumb arthritis - Trapeziectomy & suspension arthroplasty
Base of thumb arthritis
If your thumbs develop arthritis then you may find gripping and pinching objects progressively painful. Arthritis at the base of the thumb is more common in women, and may be a family tendency. The supportive ligaments generally slowly become weak, allowing increased motion at the joint level, that causes cartilage wear and development of inflammation and pain.
Some people find supportive braces or thumb wraps are helpful. These splints should be worn on bad days, or when a task would be predictably painful. They can protect a joint that may be unstable from damaged ligaments. If worn continuously they tend to cause weakness of muscles of the thumb which may not help.
Sometimes joint injection with a long acting anti-inflammatory steroid can be helpful. Many people find repeated injections less and less useful, and then surgery can be considered.
Trapeziectomy or Fusion:
Fusion of the basal joint of the thumb may be the best choice for you. The arthritis must be confined to the 1st CMC joint alone. Pan-trapezial arthritis that involves the joint with the scaphoid will not ease with 1st CMC fusion. The thumb will generally be stiffer after fusion of the 1st CMC joint, but pain will be reduced and power will be better.
Removal of the trapezium is a good choice for people with disabling pan-trapezial arthritis. Pain is much less, mobility is preserved but strength may not be increased.
Suspension arthroplasty is a term describing the use of a slip of tendon to reconstruct elements of the ligament supports of the base of the thumb. There have been many techniques described, but no published study shows a clear advantage of one technique over another for all cases. Most specialist surgeons working in this area do however prefer to reconstruct the ligaments, in the belief that for those patients for whom it succeeds, better overall strength is achieved in the hand for grip and pinch. This is still a developing area though.
Personally, I find the Scheker ligament reconstruction technique offers the best theoretical repair, and gives the most reliable outcomes in my hands. Just like knee reconstructions for ligament failure, the repair can fail if loaded too soon, and may not restore function to youthful levels! If the technical execution of the ligament repair proceeds with no trouble (95% of the time), and the postoperative care is followed in step-wise fashion with the hand therapy team then excellent results can be expected.
It does take more than 3 months of healing to become mostly normal. Strength and comfort of hand and thumb use will continue to improve over a 12 month period.
Sometimes arthritis of the basal joint causes secondary effects on the MCP joint of the thumb: if that has become unstable, or painful with use, or overextends in the effort to widen the grasp between thumb and index finger (1st web space): then surgical repair to that joint may be needed to rebalance the thumb function, at the time of the surgery to the basal joint.
The individuality of your arthritis requires a custom solution appropriate to you. That does make it harder to produce scientific studies on outcomes, but I do invite my patients to join the outcome studies through our Unit.
- Philip A. Griffin, FRACS