First dorsal interosseous muscle reconstruction with free palmaris longus graft

Abstract

BackgroundThe first dorsal interosseous muscle is crucial for abduction and stabilization of the index finger during pinch grip. A 56-year-old right hand dominant male sustained a traumatic injury of his right first dorsal interosseous muscle due to right index finger hyperextension during a fencing competition. On examination, there was scissoring of his right index finger dorsal to his middle finger. Intraoperative findings showed rupture of the first dorsal interosseous tendon from its muscle belly. Materials and methodsWhile different techniques are available, such as tendon transfer of the extensor indicis proprius, the use of a free palmaris longus tendon graft to reconstruct the first dorsal interosseous muscle has yet to be described in existing literature. This case report describes this innovative method and its outcomes. Results8 months after surgery, the patient could easily achieve index finger abduction and full active extension at the metacarpophalangeal joint (MCPJ) and interphalangeal joint (IPJ) without pain. Scissoring between his right index and middle fingers was not present. Key and tip pinch grip strengths in the affected hand were 4.5kg. No functional limitation was reported post-reconstruction and the patient has resumed fencing. ConclusionsOur reported case is the first to use palmaris longus (PL) tendon as a standalone, free tendon graft in FDI reconstruction and shows favourable outcomes. We demonstrated that a free PL tendon graft can adequately restore pinch strength and provide stability during index finger abduction without complications.