Subsequent fracture risk after hip fracture surgery in China: a three-year retrospective cohort study

This study aims to characterize subsequent fractures in a cohort of older adults undergoing hip fracture surgery in China, and to evaluate the risk factors associated with the subsequent fractures.

In this retrospective cohort study, we collected 3-year postoperative follow-up data for older patients (aged 60 years and above) who were admitted and underwent surgery for hip fractures at a single center in Beijing, China, from 2016 to 2018. The patients were categorized into two groups: those who experienced a subsequent fracture during three years post-surgery and those who did not.

Within three years post-surgery, 63.7% (1,714/2,689) of patients had follow-up visits, with a cumulative incidence of subsequent fractures of 11.3% (193/1,714). Patients in the subsequent fracture group were more likely to be female (80.8% vs. 73.8%) and older (86.9 ± 6.4 vs. 85.1 ± 7.5) compared to the non-fracture group. They also had a lower BMI, higher rates of falls, and cognitive impairment or dementia. Both groups had a history of fragility fractures (16.6% [32/193] in the recurrent fracture group and 13.0% [198/1,521] in the non-recurrent fracture group), but osteoporosis was rarely recorded in medical records (3.7% and 0.6%, respectively). Cox regression revealed an inverted U-shaped age-risk relationship with an inflection point at 90 years: each year below 90 significantly increased refracture risk by 5.4% (HR 1.054 [95% CI: 1.013, 1.096]; p = 0.009), whereas above 90 showed a non-significant declining trend (HR 0.931 [95% CI: 0.855, 1.013]; p = 0.096). Dementia (HR 1.849 [95% CI: 1.209, 2.828]; p = 0.005), recent fall history (HR 1.552 [95% CI: 1.089, 2.210]; p = 0.015), and autumn-indexed fractures (HR 1.790 [95% CI: 1.119, 2.864]; p = 0.015) independently elevated refracture risk.

This study assessed the status and long-term follow-up of subsequent fractures in hip fracture patients in China. Refracture risk is driven by nonlinear age dynamics (peaking at 90 years), modifiable predictors (dementia and recent falls), and seasonal vulnerability (autumn fractures). Implementing a fracture liaison service model tailored to national conditions is essential to reduce fragility fractures and subsequent fractures, especially for vulnerable populations.