Treatment of Mallet Finger Fracture by Extension Block K-wire Fixation

Abstract

Purpose: The purpose of this study was to evaluate the outcomes of the extension block fixation technique for a bony mallet finger. Materials and Methods: Thirty-five patients that received extension block fixation for bony mallet finger were enrolled in this study between July 2001 and October 2005. The fracture type was classified by the Wehbe and Schneider method. The average follow up period was 15 months, ranging between 12-52 months. The results were classified by the Crawford criteria. Results: There was 30 cases of type I, 5 cases of type II and no cases of type III, with 11 cases of subtype A, 22 cases of subtype B, and 2 cases of subtype C. The average time from injury to operation was 12 days, which included three cases of over 28 days. The K-wire was removed 30 days after the operation, and joint exercises were initiated immediately. There were 10 cases with excellent outcomes, 18 cases with good outcomes, 4 cases with fair outcomes, and 3 cases with poor outcomes. The poor outcome had complications such as subluxation of the DIP joint, lag between injury to operation time (more than 4 weeks), and more than 1 mm displacement. Conclusion: The extension block technique for the treatment of bony mallet finger is relatively simple and results in satisfactory bone union.