Comparison of short-term costs and 3-year complications in geriatric femoral neck fractures: hemiarthroplasty versus total hip arthroplasty

Hemiarthroplasty (HA) and total hip arthroplasty (THA) are the primary surgical options for geriatric femoral neck fractures (FNF). Our study balanced heterogeneity in baseline patient conditions and included long-term follow-up data, compared short-term costs and reoperation risks within the 3-year period, aimed to provide evidence for personalized surgical selection. This study enrolled 878 patients aged ≥ 60 years with first-time FNF treated at the Orthopedics Department of a large Grade-Three Class-A Hospital in China (2013.03–2021.12), categorized into HA and THA groups. Collected demographic characteristics and relevant clinical data, and Inverse Probability of Treatment Weighting (IPTW) was applied to adjust for baseline heterogeneity. Primary outcomes encompassed prosthesis-related complications, secondary fractures included contralateral fracture and osteoporotic vertebral compression fracture (OVCF), and short-term costs. Subgroup analyses stratified by age (60–75 vs. ≥ 75 years) and age-adjusted Charlson Comorbidity Index (aCCI < 5 vs. ≥ 5) were conducted to identify high-risk populations. The THA group demonstrated significantly higher risks of periprosthetic fracture (OR = 2.43, 95% CI: 1.09–5.41; P = 0.030) and dislocation (OR = 4.27, 95% CI: 1.44–12.66; P = 0.009) compared to the HA, but had a reduced risk of deep vein thrombosis (DVT) (OR = 0.26, 95% CI: 0.11–0.63; P = 0.003). In high-risk subgroups (age ≥ 75 and aCCI ≥ 5), we observed dramatically increased risks of periprosthetic fracture and dislocation, but there were no differences in low-risk subgroups except for DVT. Short-term cost analysis revealed that the THA incurred higher hospitalization expenses [$13,038 ($9,047–$14,795) vs. $9,043 ($8,012–$10,178)]. THA carries an elevated risk of mechanical complications within 3 years, especially among patients aged ≥ 75 years or with an aCCI ≥ 5. For these high-risk populations, HA should be prioritized to mitigate catastrophic risks. THA incurs higher short-term medical costs, but it may benefit low-risk patients through long-term functional improvement.