The TMC joint, at the base of the thumb, may be one of the most debilitating places to develop arthritis, but also one of the most common. Activities that may exacerbate TMC arthritis are those that involve forceful grip, such as opening a jar or stinging punctures, such as holding a key.
The TMC joint is a joint of the saddle between the metacarpal bone of the thumb and the bone of the trapezius, which allows the thumb a great mobility to reach the fingers. The most common cause is wear or degenerative arthritis, leading to ligament laxity and wear of the cartilage joint pad. Inflammatory arthritis, such as rheumatoid arthritis, as well as fractures, can lead to traumatic arthritis.
X-rays are most useful to confirm the diagnosis of traumatic arthritis in the joints of the hand.
The treatment consists of limiting activities, medication such as ibuprofen and bracing with a spica thumb bracelet, especially while sleeping at night. An injection of cortisone may provide some relief, but this is usually a last resort.
If, despite this treatment, a patient has pain at rest or with daily activities, surgery is indicated. A 40-minute ambulatory procedure is performed under general anesthesia. Through two incisions, the trapezius bone that makes up half of the joint is removed. A strong Kevlar suture is pulled through the bones that attach the metacarpal of the thumb like a rope. The space remaining after removal of the trapezius bone can be left open or filled with a tendon ball, although the development of the tightening procedure makes it unnecessary.
Postoperative radiographs will show the 2 buttons and the space in the hand.
After surgery, the patient is placed in a splint and, after a week, a removable bracket. The therapy to recover the movement begins one month after the surgery and lasts approximately two months.
Surgery relieves 95% of the pain and maintains the level of movement prior to surgery. Strength does not increase with surgery, since the joint is structurally not the same as before arthritis.
Video credits to John Knight YouTube channel