Flexor Pollicis Longus Rupture in a Scaphoid Nonunion: A Case Report

Background  Flexor pollicis longus (FPL) tendon rupture is a rare complication of scaphoid nonunion. Case Description  A fit active 70-year-old woman ruptured her FPL when it abraded on a painless 50-year-old scaphoid nonunion. She had asymptomatic scaphoid nonunion advanced collapse (SNAC) arthritis. At surgery, the sharp mobile volar scaphoid osteophytes were excised and the volar wrist capsule was repaired. A vascularized fat flap based on a perforator of the radial artery was used to augment the volar wrist capsule repair and to create a smooth gliding surface for the FPL. The ruptured FPL tendon was reconstructed with a palmaris longus graft. Literature Review  Complete rupture of the FPL tendon secondary to scaphoid nonunion is a rare complication. It can be easily misdiagnosed because the original injury may be unrecognized or forgotten. A consensus regarding the optimal surgical management has not been reached. Clinical Relevance  The objective of surgery in this case was to restore FPL function and prevent a recurrent rupture. The asymptomatic SNAC arthritis was not treated. No further wrist surgery was required. The patient was asymptomatic with a functioning FPL tendon 4 years after surgery.