Medium-Term Clinical Results of High-Flexion Knee Prostheses in Patients with Rheumatoid Arthritis.

ABSTRACT

OBJECTIVE: This study was performed to evaluate the function and satisfaction outcome of patients with rheumatoid arthritis (RA) who underwent total knee arthroplasty (TKA) with high-flexion prostheses. MATERIALS AND METHODS: Twenty-two patients (35 knees) using high-flexion prostheses (Zimmer, Warsaw, IN) were followed up for a period of 7-11 years from February 2007 to December 2009. Clinical and radiographic follow-up was performed using Hospital for Special Surgery (HSS), Short-Form 36 scores (SF-36), American Knee Society score (KSS), and Knee Society Total Knee Arthroplasty Roentgenographic Evaluation and Scoring System. Patient satisfaction assessments took place at the final follow-up sessions using the Marsh Satisfaction Questionnaire. RESULTS: The average ROM improved from preoperative 68.43° ± 33.78° to 95.54° ± 7.03° at the final follow-up. The HSS score and KSS score for pain improved from (46.49 ± 12.73) points to (85.46 ± 3.90) points and from 20.57 ± 5.91 points to 47.43 ± 3.51 points at the follow-up evaluation, respectively. Physical Component Summary(PCS) and Physical Component Summary (MCS) scores were 45.38 and 52.56, respectively by the end of follow-up. Deep venous thrombosis developed in one patient and one patient required surgical revision due to infection. There were no instances of prosthetic loosening. The satisfaction rate of patients was 95.5%. CONCLUSION: Although this particular model of TKA did not yield high-flexion angles (ie, 140°) required for kneeling, squatting, or rising from the floor, significant clinical and radiographic gains were evident in these patients with RA.