Acute Extensor Pollicis Longus Tendon Injury Associated with a Distal Radius Fracture: A Case Report.

BACKGROUND Extensor pollicis longus (EPL) tendon rupture is a potential complication following distal radius fracture, typically occurring several weeks after injury. Herein, we present a rare case of acute extensor pollicis longus tendon rupture associated with a distal radius fracture. CASE REPORT A 35-year-old woman visited our hospital with a distal radius fracture. At the time of examination, the thumb could be moved, although there was pain in the wrist. Computed tomography (CT) revealed a fracture line extending to the ulnar side of Lister's tubercle. During volar locking plate fixation, visual confirmation of the EPL tendon injury was conducted. According to the intraoperative finding, the EPL tendon was 70% ruptured and elongated, and the extension mechanism of the thumb was disrupted. Based on these findings, direct suture of the EPL tendon, including elongation of the ruptured tendon, was performed. One year after surgery, the EPL tendon excursion was smooth, with no limitations in thumb mobility, and the patient had returned to work. CONCLUSIONS This case highlights the importance of recognizing that EPL tendon injury can occur in conjunction with distal radius fractures. The risk of the EPL tendon injury is particularly high when the fracture line extends to the ulnar side of Lister's tubercle, which serves as the EPL tendon floor. When an EPL tendon injury is suspected based on preoperative examination and fracture type, it is important to obtain adequate informed consent and to prepare for potential EPL tendon reconstruction before surgery.