Morbidity and Mortality Analysis of Primary Total Knee Arthroplasty in Patients Over 90 Years of Age: Insights from the German Arthroplasty Registry.

Abstract

This study aimed to evaluate the safety of primary total knee arthroplasty (TKA) in patients aged ≥ 90 years by assessing complication and mortality rates. Additionally, we compared these outcomes with those of younger patient groups and identified comorbidities associated with increased morbidity and mortality. Data were obtained from a national arthroplasty registry. The study included 392,929 patients aged ≥ 60 years who underwent primary TKA for osteoarthritis. Of these, 1,284 patients were ≥ 90 years old. Patients were divided into four age groups: (I) 60 to 69 years, (II) 70 to 79 years, (III) 80 to 89 years, and (IV) ≥ 90 years. Minor and major complications and mortality during follow-up were recorded and compared across age groups and comorbidities; mortality was also compared with the general population using Federal Statistical Office data. Minor complications occurred in 58% (745 of 1,284) of cases in Group IV, compared to 21% (29,867 of 144,978) in Group I (P < 0.001), with postoperative anemia being the most common (38%). Major complications were significantly more frequent in nonagenarians (18%, 233 of 1,284) than in sexagenarians (5.2%, 7,524 of 144,978) (P < 0.001). Overall mortality increased with age, occurring in 4.0, 9.6, 17, and 36% of patients in Groups I to IV, respectively. Kaplan-Meier estimates showed significantly higher mortality for patients who have minor and major complications. At 90 years, one-year mortality was 9.1, 9.7, and 9.5% in men and 2.2, 7.2, and 15.4% in women for no, minor, and major complications, respectively, compared with 18.5 and 14.7% in the general population. Older age and comorbidities were associated with higher complication and mortality rates after TKA. Moreover, implant-related complications remain low, and with careful selection, nonagenarians can safely undergo TKA, given their lower one-year mortality than the general population.