ISSN:
1434-9949
Keywords:
First carpometacarpal joint
;
Radiography
;
Rheumatoid arthritis
;
Subluxation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract The aim of our study was to assess the incidence of subluxation of the first carpometacarpal joint (CMC I) and to evaluate which degree of subluxation produces swan-neck deformity of the thumb in rheumatoid arthritis (RA) occurring over 20 years. The hands of 83 rheumatoid factor (RF)-positive RA patients with recent (≤6 months) arthritis were evaluated radiographically at onset and at 1, 3, 8 and 15 years; 68 patients were evaluated at 20 years from entry. Subluxation was assessed in millimetres and compared with the MCP-I angle measurement to evaluate the thumb deformity. A statistical end-point analysis was performed between two different grades of subluxation. Subluxation of 2–3 mm was non-specific and only one third of these thumbs showed swan-neck deformity. At the end-point, subluxation of ≥4 mm was present in 17% of the thumbs, 81% of which had the swan-neck deformity; only five thumbs did not show this deformity, but presented deformed and unstable MCP I and interphalangeal joints. The frequency of swan-neck deformity was highly significantly (p〈0.0001) increased in the thumbs with severe CMC I subluxation (≥4 mm) compared with lesser subluxation (〈4 mm). When subluxation of the CMC I exceeds 4 mm, the swanneck deformity of the thumb is a common consequence. This deformity is often progressive, and the hand function of such patients should be followed up carefully, both clinically and radiographically.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01452260
Permalink
