Osteoarthritis after Extension Block Technique for the Bony Mallet Finger

Abstract

Purpose: The purpose of this study is to investigate osteoarthritis after treatment of bony mallet finger using the extension block method.Methods: A single institutional retrospective review identified 163 patients with bony mallet between January 2012 and July 2020 and received surgical treatment using extension block method. The radiographic examination showed that the fracture line disappeared and a bridging callus was formed and bone union was confirmed. Fractures were classified according to the Tubiana classification method. Demographic data, fracture pattern, postoperative X-ray, and late complications were analyzed. Clinical outcomes were analyzed using Crawford’s criteria.Results: Surgical treatment was performed within an average of 8.8 days after injury, and the average follow-up period was 11.6 weeks. Osteoarthritis findings were confirmed by joint space narrowing and osteophytes on radiographic examination of 32 out of 163 patients. Age, sex, occupation, location of trauma, operation time, and type of fracture did not affect the osteoarthritis after extension block. Invasion of Kirschner wire (K-wire) to the fracture surface, family history of osteoarthritis, and operation time turned out to have a statistically significant effect on osteoarthritis (p<0.05).Conclusions: Fracture surface invasion of K-wire and family history of osteoarthritis affect osteoarthritis after treatment of bony mallet.