Rheumatoid thumb deformity (Nalebuff classification type 3) appears in about 70% of rheumatoid arthritis (RA) patients, however the surgical correction is especially difficult when the trapezium absorbed.
A 58-year-old woman was diagnosed as RA at the age of 51, and has been treated with a biologic agent (tocilizumab), prednisolone (2mg) and salazosulfapyridine at another hospital. Her condition of RA was well controlled. She was referred to our hospital because of weakness in her left thumb. Radiographs and CT showed dorsal and radial dislocation of the CM joint, hyperextension of the MP joint, and severe bone defect of the trapezium. She was diagnosed as rheumatoid thumb classified as Nalebuff classification type 3. The CM joint arthroplasty using an artificial ligament (mini tight rope®) and capsulodesis with reefing of volar plate for MP joint of the thumb were performed. A temporary fixation wire of CM joint between the 1st and 2nd metacarpals and an extension block pin of the MP joint were placed.
At postoperative 9 weeks, the wire for temporary fixation of the CM joint was removed, leaving an extension block pin of the MP joint. Active motion was started at 10 weeks after surgery. At 4 months after surgery, there was no subsidence of the first metacarpal, Kapandji score of thumb opposition was 9, and the patient became able to button up and her ADL was improved.
Swan neck deformity of the rheumatoid thumb (Nalebuff classification type 3) with severe bone defect of the trapezium was treated with CM arthroplasty using artificial ligament and MP joint capsulodesis leaving an extension block pin of the MP joint. The patient showed improvement of the thumb function at 4 months after the surgery.
