By A. Kumar, C.P. Kelly
Hand and Upper Limb Unit, Robert Jones and Agnes Hunt Orthopaedic Hospital, Oswestry, Shropshire , UK

Reprinted from Injury, Int. J. Care Injured, 34 (2003), 75-78 with permission from Elsevier.

Introduction

We report a case of entrapment of the extensor pollicis longus (EPL) tendon in a bony tunnel in the dorsal radius. The patient suffered a displaced Smith's fracture of the distal radius with fracture of the distal ulna. Open reduction and internal fixation of the distal radius was performed through a volar approach. The patient developed dorsal wrist pain radiating along the line of the EPL tendon, but with almost full function of the thumb. An MRI scan of the left wrist showed entrapment of the tendon, which was confirmed at surgical exploration. A bony decompression was performed with complete relief of symptoms.

Case report

A 24-year-old right-handed man presented to the accident and emergency department with a crush injury of the left wrist, sustained while working on a milling machine. On examination, he had a laceration over the distal ulna. The wrist was grossly swollen and deformed. Altered sensation was noted in the median nerve distribution, with normal circulation in the fingers. Radiographs of the wrist showed a displaced Smith's fracture with a comminuted fracture of the distal ulna. The patient was taken to theatre for debridement, median nerve decompression, and internal fixation of the fractures. After decompression of the median nerve, the distal radius was fixed with a volar buttress plate and the ulna with a one-third tubular plate. The wound on the ulnar side was debrided and left open. After a time of 72 h, cancellous bone grafting of the ulna and splint skin grafting was performed. The fractures healed satisfactorily (Figure One) and the patient regained full function over a three-month period, but complained of pain across the dorsum of the wrist radiating along the line of the EPL tendon. He had a full range of thumb flexion. Conservative management failed to resolve his symptoms, and despite removal of all the metal work, the problem persisted. Radiographs of the wrist showed that the fractures had healed in a good alignment.