Elevated risks of pneumonia, cognitive dysfunction, and cerebrovascular disorder in super-elderly knee arthroplasty patients: insights from a nationwide Japanese database.

Abstract

Knee arthroplasty is an effective treatment option for managing advanced osteoarthritis and rheumatoid arthritis, even in elderly patients. However, super-elderly patients face increased risks of postoperative complications such as in-hospital mortality, deep vein thrombosis, pneumonia, cerebrovascular events, and cognitive dysfunction. This study aims to analyze postoperative complications in super-elderly patients (aged 85 years and older) and elderly patients (aged 70-84 years) who underwent total knee arthroplasty (TKA) or unicompartmental knee arthroplasty (UKA) using Japan's nationwide DPC database. The analysis was conducted after adjusting for confounding factors through propensity score matching. We conducted a retrospective study of 200,925 patients who underwent TKA or UKA between 2016 and 2023. After propensity score matching (1:1) based on age, sex, body mass index, surgical method, and comorbidities, 21,117 patients were included in each group. Postoperative complications, including in-hospital mortality, deep vein thrombosis, pneumonia, cerebrovascular events, and cognitive dysfunction, were analyzed. Multivariate logistic regression identified independent risk factors for postoperative complications. The super-elderly group exhibited higher odds ratios for pneumonia (2.227, 95% CI: 1.494-3.319), cerebrovascular events (1.720, 95% CI: 1.305-2.266), and cognitive dysfunction (1.767, 95% CI: 1.485-2.103). They also had more extended hospital stays and higher blood transfusion requirements. However, no significant differences were observed for deep vein thrombosis, pulmonary embolism, or in-hospital mortality. Super-elderly patients exhibit increased risks for certain complications, though not for mortality. When clinically appropriate, performing knee arthroplasty before the age of 85 may help reduce these risks.