The radial collateral ligament (RCL) of the thumb is injured much less often than the ulnar collateral ligament (UCL). The RCL is located just at the base of the thumb between the thumb and the forearm. It actually crosses the wrist line at that point. The UCL is on the other side of the wrist.

Studies of the RCL are limited. The tear is usually graded from one to three. One is a mild injury and three is a complete tear. Splinting or casting is used for grade 1 and 2 tears. Doctors disagree on the best way to treat grade 3 tears.

Some advise casting it for six to eight weeks. Others insist surgery is the only way to go. A recent study of 26 patients with grade 3 tears reported on the results of surgical treatment for grade 3 RCL tears.

Patients who had the surgery within the first three weeks of the injury had a repair. Patients who waited months to years to have the surgery had a full reconstruction. The results were excellent in both groups.

Based on this study, the authors recommended surgery in the acute stages of RCL ruptures. They predict it will reduce the risk of a painful, unstable joint and arthritis developing later.