Spontaneous Rupture of the Extensor Pollicis Longus in a Semi-professional Bodybuilder.

Spontaneous rupture of the extensor pollicis longus is a rare injury. Distal radius fractures and rheumatisms are the principal causes, but there is an increase in cases related to some professional or sports activities. We report a case of a semi-professional bodybuilder who presented with a full loss of interphalangeal thumb extension and retropulsion following trivial trauma of the left wrist. Ultrasound confirmed the diagnosis of spontaneous rupture of extensor pollicis longus, and MRI revealed a very rare and aggressive anatomical variant of Lister's tubercle. The patient underwent a transfer of the extensor indicis propius, which is the most popular technique used for hyperextension and retropulsion restitution. Aggressive anatomical forms of Lister's tubercle can explain the frequent occurrence of spontaneous rupture of extensor pollicis longus in patients who practice sports or professions with a repetitive movement of the wrist.