A major transition in the surgical treatment of
rheumatoid arthritis has been facilitated by a recent paradigm shift in its diagnosis and treatment. Improved outcomes in the treatment of the rheumatoid thumb are desirable; however, the results of conventional surgery are less than ideal. Even if the
rheumatoid arthritis is well-controlled, the progression of
thumb deformity may persist owing to an ineffective
deformity correction and an insufficient understanding of the mechanism by which the
deformity occurs. The mechanism of rheumatoid
thumb deformity should be considered, using it to base the appropriate correction. We applied a new
deformity correction procedure that accounts for the mechanism of type I rheumatoid
thumb deformity and obtained positive results without recurrence. Although the primary cause of type I
thumb deformity is believed to be an extensor mechanism failure resulting from
synovitis of the metacarpophalangeal (MCP) joint, surgical outcomes are negatively affected as a result of flexion
contracture caused by the adductor pollicis (
ADP). Because the
ADP attaches to the ulnar sesamoid on the palmar side of MCP joint, we release the
ADP tendon to improve flexion
contracture of the MCP joint. We consider release of
ADP to be effective in preventing the recurrence of flexion
contracture of the MCP joint and re-tensioning of the extensor pollicis brevis. Rheumatoid
thumb deformity can be restored by applying this procedure, improving a patient's outcome.