The relationship between component rotation angle and patients’ satisfaction scores after total knee arthroplasty in patients with rheumatoid arthritis

Abstract

Total knee arthroplasty（TKA）shows good clinical results in patients with osteoarthritis（OA）and rheumatoid arthritis（RA）. Unfortunately, some patients continued to complain after TKA. Some reports have assessed the relationship between malalignment of the knee components and patients’ satisfaction scores in patients with OA. However, few reports have assessed this relationship in RA patients. In this study, the rotational alignment of the femoral component, tibial component, and patellar component and the resection thickness of the patella were assessed based on the postoperative knee flexion angle, and these results were related to RA patients’ satisfaction scores. We used the 2011 Knee Society Score（KSS）to assess patients’ satisfaction scores. Malalignment of the femoral component, malalignment of the, and short resection thickness of the patella were corelated with a poor flexion angle and resulted in worse knee symptoms and functional activity scores. In RA patients, rotational alignment of the femoral component and patellar component and patellar resection thickness were important factors in determining postoperative knee flexion angle and relating those results to patients’ satisfaction scores.