Boxer's Fracture

The fracture of the fifth metacarpal neck (also called a boxer's fracture) is the most common fracture of the hand. Displaced fractures often result in volar angulation of the metacarpal head, shortening, and residual malrotation. Although many fractures can be treated with a splint only, surgery should be performed in patients with excessive volar angulation, relevant shortening, or rotational deformity.

Investigation was performed by Adrian Scale et al at BG Klinikum Unfallkrankenhaus Berlin gGmbH, Berlin, Germany. The video article has been published in “JBJS ESSENTIAL SURGICAL TECHNIQUES.”

Procedure

For this procedure, the injured arm of the patient is placed on an arm table. The incision is made 1 to 2 cm longitudinally over the ulnar base of the fifth metacarpal bone. The cortical bone is opened with an awl, and a bent 1.6-mm Kirschner wire is inserted into the medullary canal. After reaching the fracture region, the fracture is anatomically reduced. The Kirschner wire is then advanced into the head of the fifth metacarpal, securing the reduction. Malrotation can be addressed in this stage by rotating the wire under fluoroscopic control. After ensuring anatomical reduction clinically and by fluoroscopy, the wire is shortened under the skin, followed by closure of the incision. A mid-hand brace for splinting is utilized.

Other surgical techniques include a similar procedure that involves the use of multiple Kirschner wires, plate fixation, transverse Kirschner wire pinning, and, less commonly, retrograde headless screw fixation.

“The main advantage of this technique is the preservation of the metacarpophalangeal joint and the minimal soft-tissue damage. Additionally, the use of a single Kirschner wire provides stability at low cost. With some experience, this surgery can be performed within 20 minutes” the authors commented.

Important Tips

• Bending the Kirschner wire to ensure easy gliding in the medullary canal provides the opportunity to reduce the metacarpal neck once the wire is safely in the head.
• Aim distally as you open the cortical bone with the awl in order to facilitate the insertion of the Kirschner wire.
• The primary reduction should be made manually, not by the wire. Subacute fractures and substantially displaced fractures require direct force for a satisfactory reduction, which cannot be achieved by rotation of the wire only.
• The cortical bone on the metacarpal head is very thin. Take care not to drive the Kirschner wire through the cortical bone and into the joint.
• Shorten the wire under the skin approximately 1 cm above the bone surface; this ensures easy removal and prevents skin irritation.

Further Reading

Intramedullary Single-Kirschner-Wire Fixation in Displaced Fractures of the Fifth Metacarpal Neck (Boxer’s Fracture) Adrian Scale, Andreas Kind et al JBJS ESSENTIAL SURGICAL TECHNIQUES 2022, 12(2):e20.00050(1-2) http://dx.doi.org/10.2106/JBJS.ST.20.00050

Published outcomes of this procedure can be found at: Bone Joint J. 2019 Oct;101-B(10): 1263-71.