Bridge over Troubled Tendon? A Novel Case of Heterotopic Ossification of Lister's Tubercle Causing Extensor Pollicis Longus Tenosynovitis.

INTRODUCTION

Distal radius fractures are a common injury in adults, and surgical treatment frequently consists of open reduction internal fixation (ORIF) with a volar plate and screws. Uncommonly, heterotopic ossification (HO) may form as a result of inflammation secondary to trauma in the wrist, and once formed, surgical excision is the only effective treatment.

CASE REPORT: A healthy 57-year-old male presents with thumb pain and decreased range of motion 2 years postoperatively of a distal radius ORIF with notable dorsal comminution. Physical examination was significant for pain, weakness, and decreased range of motion with thumb extension. After initial evaluation, the patient felt a popping sensation with subsequent improvement of pain and range of motion, but he continued to have weakness with thumb extension. Radiographic evaluation revealed significant ectopic bone formation over Lister's tubercle as well as one screw protruding from the dorsal cortex of the distal radius by 3 mm. Surgical treatment revealed bridging bone creating a tunnel encasing the extensor pollicis longus (EPL) tendon with extensive tenosynovitis but without fraying. Surgery consisted of HO excision, tenosynovium debridement, screw removal, and transposition of the EPL tendon superficial to the extensor retinaculum. At follow-up, the patient had decreased pain and restoration of range of motion.

CONCLUSION

This is the first case report demonstrating HO of the dorsal distal radius about Lister's tubercle, which caused functional limitations and tenosynovitis of the EPL tendon for a patient 2 years postoperatively from a distal radius ORIF for distal radius fracture with dorsal comminution; patient had improvement after surgical intervention with HO excision and screw removal.