Intramedullary fixation of boxer's fractures: evaluation of functional results

Abstract

Introduction: The majority of the fifth metacarpal neck fractures can be treated conservatively. Nevertheless, surgical treatment is justified in certain cases. This retrospective study was designed to evaluate the clinical results of intramedullary Kirschner-wire fixation of these fractures. Material and methods: Between May 2005 and January 2006, 42 patients (40 men and 02 female) with 42 displaced fifth metacarpal neck fractures were treated at out institution by closed intramedullary Kirschner wires fixation. The assessment of patients was based on the time to union, the functional recovery and the incidence of complications. Results: Fractures were treated by intramedullary stabilization with, on median, two k-wires, with the k-wires having a median diameter of 1.4 mm. Median operating time was 30 minutes. Initial fracture angulation measured on the lateral radiographs averaged 39° in excess of the normal head shaft angle. On the immediate post operative radiographic, fracture angulation averaged 6°, designating an average 95% correction of the initial angulation. Union occurred in all patients. The average time to union was 8,4 weeks. There were eight postoperative complications: two superficial infections, and six mechanical irritations of the Kwires. The pins were removed in 40 cases. Removal of the pins was performed in all cases as an outpatient procedure under local anaesthetic with no complications noted. At final follow-up, fracture angulation averaged 6.9° . The average MCP arc of motion at the last follow-up was 95° (range, 85 - 105). Many of the patients (23 patients) had less than 50% of normal function immediately after union of the fractures but improved considerably by 2 weeks and all had more than 90% (90% - 100%) normal function at 2 months post operative. Discussion: The X-rays of the metacarpal fractures in our patients showed, on median, a palmar dislocation of 39°, which is why closed reduction and intramedullary k-wire stabilization was performed. Compared with the other available surgical methods, intramedullary fixation of metacarpal bones is characterized by its simplicity and the fact that fracture treatment does not harm the sliding tissue. Conclusion: Intramedullary Kirschner wire fixation is a minimally invasive method for stabilizing the fifth metacarpal neck fractures.

Key-words: Metacarpal fractures, Internal fixation, Intramedullary Kirschner wire