[Tendon rupture of the extensor pollicis longus tendon in rheumatoid arthritis].

Seven patients with subcutaneus of the extensor pollicis longus tendon (EPL) in rheumatoid arthritis were studied. There were one man and six women. The mean age of the patients was 56. 9 years, with a range of 47 to 83 years. The duration of the disease was from 0.2 to 6 years, its average 3 years. An interval between rupture of the tendon and operation was 9 days to 18 months. Tendon transfers of the extensor indicis proprius tendons were performed in 3 cases, sutures in 2 cases and free tendon graft of the palmaris longus in one case. All cases showed very active tenosynovitis around the EPLs, which were ruptured near Lister's tubercle. The histopathological findings of the ruptured EPL revealed that synovial proliferative tissue with chronic inflammatory cells infiltration were invading into the tenion tissue directly. The synovial granulatins might weaken the tendon and repetitive mechanical stress on the tendon at Lister's tubercle could result in the rupture of EPLs.