The hamate is a small bone in the wrist. It is one of eight carpal bones and is located on the inside edge of the wrist.
(the edge on the opposite side from the thumb).
The hamate has a hook (called the hamulus) where it connects with the ulna bone in the forearm. This hook is sometimes broken in athletes who use rackets, clubs, or bats. It can be a hard injury to diagnose. The pain of a broken hamulus is much like the pain from an injury to the wrist ligaments or muscles.
A broken hamulus most often doesn’t heal well. Pain often remains, and gripping can be difficult. Usually the pain is caused by a break that has not fully healed, called a nonunion. A nonunion is usually treated by surgically removing the hamulus.
These doctors believe that in some cases the pain is caused by a partial union. In a partial union, the break heals well enough so that it looks healed on X-rays. However, it still causes pain and problems gripping.
The authors write about eight patients who seemed to have a partial union of the hamulus. All eight were injured while playing golf or baseball. After several weeks of other diagnoses, it was found that they had fractures of the hook of the hamate. The break looked as if it had healed, but pain continued. A special type of X-ray called a CT (computed tomograpy) scan was used to help in the diagnosis. CT scans are very useful when doctors need to see if there are problems with bones. In this case, the CT scan did show faint evidence of a partial union. The doctors finally removed the hamulus. Within an average of eight weeks, all the athletes were pain-free and back to their sports. Grip measurements showed that they had gotten their strength back.
The authors recommend that doctors should always use CT scans when looking for problems with the hamate. They also suggest that doctors should suspect injury to the hamulus when golfers, baseball players, or tennis players have problems with grip strength and pain in the wrist.