Abstract
Objectives: In this study, we aimed to compare functional and radiological outcomes of single versus double cortical procedure using a Kirschner wire (K-wire) through extension block method (EBM) in the surgical treatment of bony mallet finger.
Methods: Between January 2019 and April 2020, a total of 21 patients (13 males, 8 females) who underwent EBM for a bony mallet finger were retrospectively analyzed. The patients were divided into two groups as Group 1 (n=9) and Group 2 (n=12). Surgical treatment was performed using dorsal K-wires through a single cortical line in Group 1 and through a double cortical line in Group 2. Functional outcomes were evaluated using the Crawford’s evaluation criteria. Time to union in the fracture line was compared between the groups.
Results: The mean age was 37 (range, 22 to 57) years and the mean follow-up was 11 (range, 8 to 15) months. According to the Crawford’s criteria, the outcomes were excellent in 19 patients and good in two patients. There was no statistically significant difference in the functional outcomes between the groups (p>0.05). Time to complete union was 31 days in Group 1 and 29 days in Group 2 (p=0.06). Radiographic complete union was achieved in both groups. Serous discharge was observed from the entry site of the K-wire in one patient in each group. After one-week oral antibiotherapy, serous discharge resolved.
Conclusions: The EBM is an effective and valid method in the treatment of mallet finger, and both the single and double cortical procedures through the dorsal K-wire yield comparable functional and radiographic outcomes.

Key words: Mallet finger, extension block method, Kirschner wire