AVULSION FRACTURES OF THE METACARPOPHALANGEAL JOINTS OF THE FINGERS

Abstract

Fractures about the radial or ulnar aspects of the base of the proximal phalanx or the metacarpal head represent collateral ligament avulsion injuries. Unlike such injuries in the metacarpophalangeal joint of the thumb these injuries are rare and have received scant attention in the literature.

The results of open reduction and internal fixation, highlighting the surgical approach and technique, of collateral ligament avulsion fractures about the metacar-pophalangeal joints of the fingers are presented.

Over a five year period sixteen patients presented to the hand injury service with the above injury. Thirteen of these fractures occurred at the base of the proximal phalanx. Fourteen were acute injuries and two non-unions. These fractures affected a predominantly young population (average age 24 years) and the majority were sustained during sporting activities. All were treated by ORIF except for one in which the patient declined operative treatment. Metacarpal head fractures are assessed through a standard dorsal approach but as the collateral ligament inserts into the volar - lateral aspect of the proximal phalangeal base access to this fracture is best achieved via a volar approach to the digit. Fractures were stabilized with a single interfragmentary screw.

Surgical fixation gave satisfactory results in fourteen cases. All these patients had a full range of finger movement within 3 weeks. One patient developed symptoms suggestive of RSD. At 3 months review all fractures treated by ORIF had united. The patient who declined surgical treatment developed a symptomatic non-union.

Conservative treatment of these unstable fractures leads to non-union. The surgical anatomy dictates the surgical approach, with fractures at the proximal phalangeal base best accessed via a volar approach. ORIF restores joint surface congruity, establishes union and provides stable fixation to allow early mobilisation and return to normal activities.