A Rare Case of Extensor Digitorum Communis Rupture Due to Pancarpal Arthritis.

We report the case of a 71-year-old man who presented to our clinic with extensor digitorum communis (EDC) tendon rupture associated with pancarpal arthritis. He presented with a history of prolonged chainsaw usage. Later that day upon waking up, he noticed an inability to extend his small and ring fingers. On examination, the EDC of the ring and small fingers showed zero power. Radiographs of the wrist joint showed pancarpal arthritis with a dorsally displaced lunate along with distal radio-ulnar joint (DRUJ) osteoarthritis (OA). During surgery, a sharp posterior lunate prominence was noticed to be the cause of the attrition and rupture of EDC. The DRUJ surface was relatively smooth. Proximal row carpectomy and transfer of extensor indicis proprius (EIP) to EDC reverse end-to-side were done. Postoperatively, the patient gained full extension. There are no other similar cases reported in the literature.