Wrist involvement in rheumatoid swan-neck deformity.
Two observations have led to the consideration of another possible factor in the etiology of rheumatoid swan-neck deformity. Distraction of the rheumatoid wrist with correctable carpal collapse and reversible swan-neck deformities resulted in easier initiation of proximal interphalangeal joint flexion, not found in hands with boutonniere deformity or lack of deformity. Review of x-rays of rheumatoid patients with swan-neck deformity indicates that most have evidence of carpal collapse. With carpal collapse and proximal migration of the carpal-hand unit, long or extrinsic motor systems are no longer working at physiological length or optimal efficiency. An imbalance is created, resulting, in effect, in an "extrinsic-minus" phenomena and swan-neck finger deformity.
D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000150:complications*; D002348:Carpal Bones / Q000000981:diagnostic imaging; D005260:Female; D005385:Fingers / Q000000981:diagnostic imaging; D006227:Hand Deformities, Acquired / Q000000981:diagnostic imaging / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011859:Radiography; D014953:Wrist