Boxer's knuckle in the professional athlete.

Injuries to the extensor mechanisms of the fingers can be career-ending in professional athletes if not treated appropriately. We identified 8 professional athletes who underwent 11 direct metacarpophalangeal joint extensor mechanism repairs including centralization of the extensor tendon and sagittal band repair between 1989 and 1994. Success of the operative procedure was determined by the athlete's attainment of full range of motion, return to professional sports, and no need for additional surgical intervention. The metacarpophalangeal joints of the long and little fingers were most commonly involved. The position of the extensor mechanism disruption and the direction of the tendon subluxation varied. Capsular tears were identified in seven joints and none were repaired. At follow-up, each athlete had regained full range of motion and each had returned to professional sport an average of 5 months postoperatively. No patient required additional surgery. In this series, the principal lesion in metacarpophalangeal joint injury was extensor mechanism disruption with a predictable sagittal band tear and either a radial or ulnar subluxation of the central tendon. We recommend centralization of the extensor tendon and sagittal band repair without capsular repair as a treatment of choice for this injury, particularly in the athlete.