New Test for Sports Injury of the Hand
In this report, hand surgeons from the University of Florida use a case study to demonstrate a new test for fractures of the hamate bone in the hand. The hamate bone is one of the many small bones in the wrist. It lines up with the base of the fourth (ring) and fifth (baby) fingers.

On the palmar side of the hand and wrist, the hamate bone has a projection of bone. This bit of bone is referred to as the hook of the hamate. There are many ligaments, muscles, and tendons that either attach directly to the hook of the hamate or sling around it like a pulley.

The anatomy is significant because with so many different soft tissues affecting the hamate bone, it is at risk for injury. When does this happen most often? When a baseball player, golfer, or racquet sports player of any kind swings the bat, golf club, or racquet held in the hands.

While swinging the bat, club, or racquet, the hand and wrist move into a position of ulnar deviation (movement toward the small finger). The forearm, wrist, and hand move from a position of pronation (palm down) to supination (palm up). Direct pressure and shearing forces are applied to the hook of the hamate. It's actually a wonder the hook of the hamate doesn't break off more often.

In the case of this professional baseball player, there was a severe, sharp pain at the time of the fracture. This happened as the bat connected with the ball. The patient was unable to keep playing despite trying to do so. He continued to have a painful wrist. The severe pain subsided to a feeling of tenderness over the hamate bone when pressed.

It was three months before an accurate diagnosis was made. Why so long? This isn't an easy injury to diagnose. It requires understanding of the clinical picture (history of injury and exam) that goes with hook of the hamate fractures.

Regular X-rays don't show a problem. The special carpal tunnel view must be taken with the forearm, wrist and hand in a position of slight (30-degrees) supination. This test position puts the hand midway between a thumbs-up position and fully turned palm up. The best test for confirming a diagnosis of hook of the hamate fracture is a CT scan.

And now the authors introduce a clinical test they call the hook of the hamate pull test or HHPT to add to the surgeons' testing tools. Here's how it's done: the patient's hand is placed palm up. The wrist is placed in a fully ulnar deviated position (wrist tilted away from the thumb). The proper test position is essential to getting accurate test results.

The small and ring fingers are flexed or bent as the examiner applies pressure to the pads of the tips of those two fingers (as if trying to straighten the fingers). The test position loads the flexor profundus tendons of the two fingers. Those two tendons come alongside the hook of the hamate. When they contract, they push (displace) the broken hook off to the side. The result is a reproduction of the severe, sharp pain at the wrist where the hamate is located.

In all the cases tested, the pull test was always positive when there was a true hook of the hamate fracture. The test is not considered positive when generalized wrist pain occurs -- only when the severe, sharp pain from the original injury is reproduced. A CT scan can confirm the diagnosis.

Treatment is surgery to remove the broken fragment of bone. Without surgery, the fractured hook can shift away from the hamate and become displaced. The jagged edges of the bone can cut through nearby tendons and ligaments. The result can be chronic pain, loss of motion, weakness, and eventual disability.

The professional baseball player in this case study was 26-years old and had a full career ahead of him. Without the proper diagnosis and treatment, he may have lost his chance to continue playing. As it was, he was benched for three extra months that might not have been necessary if the correct diagnosis had been made early on.

But all's well that ends well -- he was able to return to full participation with no further problems. The authors offer this information and the test they developed to all sports physicians, hand surgeons, and physical therapists. Anyone working with athletes who are using any kind of implement (club or bat) to swing and strike a ball with enough force to fracture the hook of the hamate will want to know about the pull test.
Thomas W. Wright, MD, et al. Hook of Hamate Pull Test. In Journal of Hand Surgery. November 2010. Vol. 35. No. 11. Pp. 1887-1889.