Fragment specific dorsal kirschner wire extension block pinning in mallet fractures-a retrospective study of 20 cases

Abstract

Percutaneous extension block pinning is one of the treatment modalities for displaced bony mallet injuries. Various technical modifications with one or more Kirschner wires have been described. The purpose of this study is to analyze the outcomes of fragment-specific dorsal Kirschner wire fixation for mallet fractures. Twenty patients with mallet fractures were divided into dorso-radial, dorso-ulnar and central based on the displaced fragments in posteroanterior radiographs. A single dorsal Kirschner wire reduced the specific dorsoradial or dorsoulnar fragment along with an additional transarticular Kirschner wire. Two dorsal wires reduced the centrally displaced fragment. We analyzed the fracture size, pre- and postoperative articular gap and dorsal gap, union, postoperative range of movement, visual analogue score, and functional outcome according to the Crawford evaluation score. The mean age of the patients was 28 years (range, 19–41 years.). We saw dorso-radial displacement of the fracture fragment in eight patients, central in seven patients, and dorso-ulnar in five patients. The mean follow-up was 24 months (range, 18–29 months). Nineteen of the 20 patients achieved good radiological union. Fragment-specific fixation with 1 or 2 Kirschner wires significantly improved articular gap and dorsal gap (p < 0.05). Seventeen of 20 patients achieved a good or excellent Crawford score. Fragment-specific fixation with one or two Kirschner wire is a rational approach for displaced mallet fractures. The technique is simple and reliable. This treatment modality achieves good radiological union and functional outcome. IV. • Fragment specific fixation is a rational approach for displaced mallet fractures. • The technique is simple, reliable and straightforward. • This treatment modality produces good radiological union and functional outcome. • We suggest first Kirschner wire as the key step for fracture fragment reduction. • A radial sided Kirschner wire for dorso-radial displacement. • An ulnar sided for dorso-ulnar displacement. • Two parallel dorsal Kirschner wires for central fragment.