Objective: To investigate the treatment of the displaced neck and subcapital fractures of the fifth metacarpal.
Methods: Thirty-one patients with the neck and subcapital fractures of the fifth metacarpal had been operated on with antegrade intramedullary fixation between January and August 2005. There was 11 subcapital fractures (group A), and 20 neck fractures (group B). Following closed reduction of the fracture, a blunt 2.0 mm diameter K-wire, which was pre-bent into 20 degrees at the distal end, was inserted into the medullary canal of the fifth metacarpal and fixed the fractures. Postoperatively, patients in group A were immobilized in a short arm plaster splint for 4 weeks, and the ones in group B were treated with unrestricted mobilization.
Results: Operative time was 18 min averagely (range 5 to 30 min). Twenty-nine of 31 patients obtained anatomic reduction, and 2 patients had 2/3 apposition of bone end and no rotational deformity. Follow-up was available for all patients. The average follow-up interval was 4 months, with a range of 3 - 6 months. The head/shaft angle of the fifth metacarpal in group A was 63.4 degrees +/- 14.5 degrees preoperatively, and 15.0 degrees +/- 2.5 degrees postoperatively, and 15.4 degrees +/- 2.6 degrees in 3 months postoperatively. The difference between preoperative and postoperative angles was highly significant. The range of motion of the metacarpal joint was 89.5 degrees +/- 4.3 degrees postoperatively, which was not significantly different compared with that of uninjured side. The head/shaft angle in group B was 59.1 degrees +/- 10.0 degrees preoperatively, and 15.9 degrees +/- 2.5 degrees postoperatively, and 15.5 degrees +/- 2.8 degrees in 3 months postoperatively. The difference between preoperative and postoperative angles was highly significant. The range of motion of the metacarpal joint was 88.6 degrees +/- 3.6 degrees postoperatively, which was not significantly different compared with that of uninjured side.
Conclusions: The technique is technically easy to perform, minimally invasive, low-cost, allowing early hand mobilization, with good functional results and low morbidity, and it has been proved to be an ideal method.