Epidemiological trends in periprosthetic hip and knee fractures in older adults in Japan, 2019-2023: A descriptive study.

Abstract

Japan is one of the world's most aged societies, and the number of joint replacements is increasing. However, studies investigating the recent incidence and treatment patterns of periprosthetic hip and knee fractures (PF) in Japan remain limited. This study aimed to clarify recent trends in case counts and treatment patterns of PFs among Japanese adults aged ≥65 years. We conducted a descriptive study using a hospital administrative database provided by JMDC Inc. from 2019 to 2023. We included 2767 patients aged ≥65 years hospitalized for PF in 239 hospitals that continuously contributed data during this period. We assessed annual PF case counts, treatment patterns (open reduction and internal fixation [ORIF], revision arthroplasty, implant removal, conservative treatment), time to surgery, resource use (length of stay, hospitalization cost), and in-hospital mortality. Trends were tested using the Cochran-Armitage trend test, linear regression, and multinomial logistic regression. From 2019 to 2023, PF hospitalizations increased steadily from 1.45 to 1.98 annual cases per hospital. Periprosthetic hip fracture rose steadily each year, climbing 40.2 % over the same 5-year period. Women comprised 85.3 % of cases. Surgical intervention occurred in 53.2 % of patients (ORIF, 45.1 %; revision arthroplasty, 7.6 %; implant removal, 0.5 %), with no clear change in procedure choice over time (ORIF, P = 0.79; arthroplasty, P = 0.89). Mean time to surgery was 5.4 days, mean length of hospital stay was 43.7 days, mean hospitalization cost was $12,888, and in-hospital mortality was 1.6 %, without showing no clear trend change. From 2019 to 2023, PF case in older Japanese adults increased gradually each year, whereas surgical procedures, time to surgery, length of hospital stay, hospitalization costs, and in-hospital mortality showed no clear trend changes. These descriptive data may be useful for understanding recent epidemiological trends in PFs.