Fractures of the neck of the fifth metacarpal bone. Medium-term results in 28 cases treated by percutaneous transverse pinning.

The purpose of this study was to report the medium-term results in 28 patients affected by closed displaced fractures of the neck of the fifth metacarpal bone (boxer's fracture) with an associated severe swelling of the hand, who were treated with percutaneous transverse K-wire pinning, to verify the effectiveness of this surgical treatment. We opted for this treatment in all cases in which malrotation of the fifth finger and volar angulation of the metacarpal head greater than 30° were associated with a severe swelling of the hand. All the patients were reviewed clinically and radiologically at an average of 25 months after surgery. At the final follow-up, no patient reported residual pain. All patients had full extension of the fifth finger, except two in whom we observed a limitation of the extension of the fifth metacarpophalangeal (MP) joint of about 10°, without significant impairment of hand function. All patients had at least 90° flexion of the fifth MP joint and full range of motion of the interphalangeal (IP) joints. No patient had rotational deformity of the fifth finger with a deficit of grip strength. At the final follow-up, a residual palmar angulation of the head of the fifth metacarpal was found in three patients, with a mean of 7°. The disabilities of the arm, shoulder and hand (DASH) scale had a mean value of 5, and all patients considered their result as good or excellent. We recommend percutaneous transverse pinning in all boxer's fractures in which operative treatment is indicated, especially in patients with severe soft-tissue swelling. The surgical procedure is easy to perform, and surgical results are generally good.