Attritional flexor tendon rupture due to a scaphoid non union imitating an anterior interosseous nerve syndrome: a case report.

A case is presented of acute loss of function of flexor pollicis longus and profundus tendon to the index finger. Although the aetiology was obscure, the acute onset suggested a mechanical cause rather than a nerve compression disorder such as anterior interosseous nerve palsy. X-rays showed an ununited scaphoid fracture related to an injury many years previously. Surgical exploration revealed attritional rupture of flexor pollicis longus and partial division of profundus tendon to index finger by a spicule of ununited scaphoid which had eroded through the volar capsule. Removal of the spicule and tenodesis of flexor pollicis longus gave a good long term result.