Abstract
Rheumatoid arthritis is comparatively often accompanied by subcutaneous rupture of the finger extensor tendon. In the present study we examined the preoperative status to determine the factors accountable for such rupture. The subjects were 27 rheumatoid patients (53 fingers) with extensor tendon rupture, 21 females and 6 males, and with a high incidence of those in their fifties or sixties (16 of 27 cases : 60%) . The rupture was predominantly in the right hand, most frequently in the ring and little fingers (21 of 27 cases: 78%) . X-ray findings of the wrist joint were noted more frequently to be in the advanced Steinbrocker's criteria stages III and IV. Ulnar distal dorsal dislocation was noted in 16 of 24 cases (67%), excluding those with thumb tendon ruptures. The scallop sign, an erosive change in the distal radioulnar joint as designated by Freiberg, was noted in 15 of these (62%) . Both findings may possibly be related to the factors responsible for the mechanical wear of the extensor tendon.
