The phenotype of pelvic and acetabular fractures in adults aged 50 and older: a national database analysis in the Netherlands

Brief Nationwide data show rising pelvic and acetabular fracture incidence, yet patient profiles and outcomes remain underexplored. In our cohort of 7,120 patients ≥50 years, pelvic fractures were frailer overall while mortality was similar to acetabular fracture patients. Findings support distinguishing fracture types and considering pelvic fractures as major osteoporotic fractures. Pelvic and acetabular fractures are increasingly common in aging populations and carry substantial clinical and societal burdens. As these injuries are often grouped together despite potentially different patient characteristics and outcomes, this study aimed to provide a comprehensive, nationwide phenotypic description of patients aged 50 years and older with pelvic or acetabular fractures in the Netherlands. A retrospective population-based cohort study was conducted using national claims and population data from Statistics Netherlands (CBS). All individuals aged ≥50 years diagnosed with a pelvic or acetabular fracture in 2019 were included. Demographics, comorbidities, treatment modality, care utilization, 1-year readmission, and mortality were compared between fracture types and sex. 7120 patients were included (6091 pelvic, 1029 acetabular). Pelvic fracture patients were older than acetabular fracture patients (mean age 77 vs 74), often female (79% vs 36%), with higher pre-injury rates of osteoporosis, connective tissue disease, and polypharmacy (all p < 0.05). Acetabular fractures showed more hospital admissions (53% vs 35%), surgical treatment (28% vs 4.4%), and complication-related readmission (9.7% vs 1.8%), most evident in male patients. New major fracture rates (6.6% vs 8.4%) and 1-year mortality rates (15% vs 17%) were comparable. Pelvic and acetabular fractures reflect distinct phenotypes in patients aged 50 and older, with pelvic fractures more closely linked to frailty and osteoporosis, most apparent in females. These findings support differentiating between fractures in research and clinical care and call for reconsideration of pelvic fractures within major osteoporotic fracture definitions, as their clinical profile seems similar to that of hip fracture patients.