Open reduction and K-wire fixation of mallet finger injuries: mid-term results

Objectives: We evaluated mid-term results of surgical treatment of mallet finger injuries in patients in whom close reduction was not successful. Methods: The study involved 34 patients (26 males, 8 females; mean age 27 years; range 21 to 37 years) with mallet finger deformity due to avulsion fracture of the proximal dorsal lip of the distal phalanx. According to the Doyle classification, all injuries were type IVb. Following unsuccessful attempts of closed reduction, the patients were treated with open reduction and K-wire fixation. Cast immobilization of the distal interphalangeal joint was employed for four weeks and rehabilitation was started after removing the K-wires in the sixth week. Radiographic and clinical assessments were made according to the Doyle and Crawford criteria, respectively, after a mean follow-up period of 18 months (range 11 to 34 months). Results: Radiographic union was achieved in all the patients and an anatomic reduction was obtained in 31 patients (91.2%). According to the Crawford criteria, the results were excellent in 27 patients (79.4%), good in four patients (11.8%), and moderate in three patients (8.8%). Patients with a good result had a mean extension loss of 5°, and those with a moderate result had a mean flexion loss of 10°. The remaining patients had full range of motion of the distal interphalangeal joint. None of the patients developed joint subluxation, narrowing of the joint space, or degenerative changes. Conclusion: An anatomical reduction is essential in mallet finger deformities. Open reduction and internal K-wire fixation can be preferred due to its low complication rate and ease of application in patients whose mallet deformity cannot be treated by closed reduction.