Quality of life after staged bilateral total knee arthroplasty: a minimum five-year follow-up study of seventy-eight patients

Purpose: Although many studies have been performed to evaluate the quality of life (QOL) and patient satisfaction after total knee arthroplasty (TKA), almost all evaluations were performed in patients after unilateral TKA or in patients after mixed unilateral and bilateral TKA. Accordingly, this study aimed to evaluate QOL after staged bilateral TKA. Methods: A total of 78 patients who underwent staged bilateral TKA for varus knee osteoarthritis were included in this study. All patients had longitudinal follow-up evaluations for at least five years. QOL was assessed by the Japanese Knee Osteoarthritis Measure (JKOM), a disease-specific and patient-derived QOL measure for Japanese patients. Conventional objective outcome scales, including the Knee Society Score and the Timed Up and Go test, were also assessed. In addition, QOL and objective outcomes were compared between the younger (≤ 80 years, average 75.8 years) and older (> 80 years, average 84.7 years) age groups at the final follow-up. Results: Improvements in both JKOM and objective outcomes reached a plateau one year after staged bilateral TKA. Improvements were prolonged for more than five years. There were no statistically significant differences in JKOM or objective outcomes between the younger and older age groups, despite an 8.9-year difference in the average age. Conclusions: This was the first longitudinal study to evaluate QOL and objective outcomes after staged bilateral TKA for a period of at least five years. Improvements in QOL and objective outcomes reached a plateau one year after staged bilateral TKA and were prolonged for more than five years. No significant differences were observed in outcome scores between the younger and older age groups.