Coronal fractures of the body of the hamate: Two case reports

Abstract

Fractures of the hamate were classified by Milch (1) into body fractures and hook fractures; fractures of the body of the hamate were subdivided into those occurring on the radial side and those occurring on the ulnar side of the hook. Bowen (2) presented a hamate fracture in the coronal plane and, therefore, added a third category -fractures to the body of the hamate. The two cases described in this report are examples of this rare type of fracture; both were associated with disarticulations at the base of the fourth and fifth metacarpals. Open reduction and internal fixation led to rapid recovery in terms of stabilization of the hamatometacarpal joint and restoration of hand function. CASE PRESENTATIONS Case 1A 29-year-old, right-hand dominant woman was referred five days after punching a steel door with her closed right fist. She was seen by physicians at the emergency department of a local hospital, where she was placed in a fibreglass splint after reduction of the fifth metacarpal.Follow-up physical examination revealed minimal to moderate swelling and ecchymosis over the base of her right fifth metacarpal. X-rays revealed a hamate intra-articular fracture with the fifth carpometacarpal joint (Figure 1). Displacement was noted to be approximately 3 to 4 mm. An open reduction was recommended to reduce the dislocated fragment of the hamate, and eight days after the injury, the patient underwent open reduction and internal fixation.Maintenance reduction of the fifth metacarpal was achieved by two 1.1 mm Kirschner wires driven between the fourth and fifth metacarpals. The dislocated fragment of the hamate was positioned and fixed in place with a 0.7 mm Kirschner wire. Two 1.2 mm screws were then used with a plate over the fragment, and the 0.7 mm Kirschner wire was removed. The hand and wrist were immobilized by a volar plaster splint for three weeks, at which time it was replaced by a short-arm cast to immobilize the extremity for an additional three weeks. Six weeks after the operation, the Kirschner wires were removed (Figure 2). The patient returned to full activities by 12 weeks after surgery and was asymptomatic when seen at eight months postsurgery.Can J Plast Surg Vol 6 No 2 Summer 1998 81 CASE REPORTCorrespondence: Dr PA Binhammer, Sunnybrook Health Science Centre, H-210, 2075 Bayview Avenue, North York, Ontario M4N 3M5. Telephone 416-480-6731, fax 416-480-6800, e- Coronal fracture of the body of the hamate with associated dorsal dislocation at the bases of the fourth and fifth metacarpals is rare. Two cases of this injury, treated with open reduction and internal fixation, are reported. As well, other reports of coronal hamate fractures are reviewed.