Changes in knee joint destruction patterns among patients with rheumatoid arthritis undergoing total knee arthroplasty in recent decades.

Radiographs of TKA recipients with RA are increasingly presenting osteoarthritic features in recent decades. Key Points • Using automated measurement software, morphological parameters were measured from radiographs of 831 patients with rheumatoid arthritis who had undergone TKA in the past 16 years. • Cluster analysis based on the radiographic parameters revealed that the radiographs of patients with end-stage knee arthritis requiring total knee arthroplasty were classified into three groups. • In patients with rheumatoid arthritis who have undergone total knee arthroplasty in the past 16 years, the proportion of clusters with features of osteoarthritis and difficult-to-treat rheumatoid arthritis has increased, while the proportion of conventional rheumatoid arthritis has decreased.