The anatomy of de Quervain's disease. A study of operative findings.

We have studied the anatomical findings at operation on 67 patients with De Quervain's disease, 5% of whom had bilateral lesions, compared with published series of cadaveric dissections. There was division with a septum in the extensor compartment in 60%. The abductor pollicis longus had more than one tendon in 76% and extensor pollicis brevis was represented by a single tendon in 96%. If there was an anatomical predisposition to the condition, more cases would have been bilateral. A septum and a crowded compartment are mainly responsible for the failure of steroid injections.