Thumbs Up for Silicone Joint Replacement
Arthritis can cause severe problems in the thumb. The small wrist bone at the base of the thumb (trapezium) can become painful and may begin to slide out of place, called joint subluxation. This can make it difficult and painful to pinch or grip.

Treatment for this problem includes rest, a splint or brace, drugs, and surgery. The surgeon may remove the trapezium or fuse it to another bone to keep it from moving. Sometimes, the tendons and ligaments around the thumb are used to separate and hold the joint.

The best treatment option may be a silicone implant. Silicone is a chemical substitute for rubber that is stable and doesn't react or heat up. It can be formed into the shape of the trapezium and inserted into the thumb to replace it. The first silicone implant for the thumb was done in 1965. Since then, the implant and the surgery have both been changed and updated many times.

In the early days of silicone implants, swelling of the joint lining and fracture of the implant itself were problems. Sometimes, the implant would bend out of shape. This led to joint subluxation. Over time, doctors learned better ways to do the surgery.

The kind of patient selected for this surgery is also important. Patients with jobs that have low activity are good candidates. The new joint works well for patients who have advanced arthritis in the base of the thumb.

When used properly, the silicone implant is a very good treatment choice for thumb arthritis. Very few problems occur, and most patients have good, painfree motion for years.
Hari P. Bezwada, MD, et al. Long-term Results of Trapeziometacarpal Silicone Arthroplasty. In The Journal of Hand Surgery. May 2002. Vol. 27A. No. 3. Pp. 409-417.