Fractures of the hook of hamate: radiographic signs.

Isolated fractures of the hamulus, formerly considered rare, are being seen more frequently. Many of these injuries are sports related, particularly in golf, tennis, racquetball and baseball players. Failure to make an early diagnosis can result in severe pain and sometimes incapacitating disability. We studied the clinical and radiological findings in 12 patients who had fracture of the hook of the hamate. We propose three radiographic signs of fracture that are readily seen on routine PA projections: "absence" of the hook of the hamate; "sclerosis" of the hook; and lack of cortical density, i.e., a barely visible outline, of the hamulus.