Artroplasia de reemplazamiento en artritis reumatoide de hombro. (Inglés)

Ofer Levy, MD, MCh(Orth)1, Lennard Funk, MSc, FRCS(Tr and Orth)2, Giuseppe Sforza, MD3 and Stephen A. Copeland, FRCS4
1 Reading Shoulder Unit, Royal Berkshire Hospital, Reading RG1 5AN, United Kingdom. E-mail address: oferlevy@readingshoulderunit.com 2 Hope Hospital, Manchester M6 8HD, United Kingdom 3 Unita di Ortopedia, Ospedale "S. Maria delle Grazie," Matera 70125, Italy 4 Reading Shoulder Unit, Berkshire Independent Hospital, Reading RG1 6UZ, United Kingdom

Investigation performed at Reading Shoulder Unit, Royal Berkshire Hospital, Reading, United Kingdom

Background: Shoulder arthroplasty with a stemmed prosthesis is a recognized treatment for rheumatoid arthritis of the shoulder. The humeral component of the Copeland cementless surface replacement arthroplasty consists of a cup for surface replacement with a short central peg for primary fixation to the bone. We hypothesized that surface replacement may offer some advantages over stemmed prostheses.

Methods: Between 1986 and 1998, seventy-five shoulders underwent surface replacement arthroplasty (thirty-three hemiarthroplasties and forty-two total shoulder arthroplasties) for the treatment of rheumatoid arthritis. The results of these procedures were reviewed after an average duration of follow-up of 6.5 years. Patients were assessed with use of the Constant score, a patient satisfaction score, and radiographs.

Results: The average Constant score was 47.9 points (age and sex-adjusted score, 71%) in the hemiarthroplasty group and 53.4 points (age and sex-adjusted score, 76%) in the total shoulder replacement group. The mean range of active flexion improved from 50° in the hemiarthroplasty group and 47° in the total shoulder replacement group to 101° and 104°, respectively. Seventy-two of the seventy-five shoulders were considered by the patients to be much better or better at the time of the review. Of the sixty-eight humeral implants that were evaluated radiographically, fifty-six (82%) showed no lucencies, eleven (16%) showed localized lucencies of <1 mm in width, and one was definitely loose. Of the thirty-nine glenoid implants that were evaluated radiographically, nineteen (49%) showed no lucencies, nineteen showed localized lucencies of <1 mm, and one was definitely loose. No lucencies were observed adjacent to the hydroxyapatite-coated implants. Thirty-nine (57%) of the sixty-eight shoulders showed some degree of superior subluxation. Three patients required a major reoperation: two required a revision because of loosening of both components, and one patient with pain at the site of a hemiarthroplasty had a revision to a total shoulder arthroplasty to provide relief.