Bipolar hemiarthroplasty versus total hip arthroplasty in femoral neck fracture patients: results from Lithuanian Arthroplasty Register

Introduction: Elderly patients with displaced femoral neck fractures (FNF) are usually operated with arthroplasty but with various combinations of implants and approaches. Thus, the optimal treatment is still controversial. We aimed to compare the results between the cemented bipolar hemiarthroplasty (HA) and total hip arthroplasty (THA) patients operated for FNF regarding revision rate at 1 year postoperatively. Methods: The data were derived from the Lithuanian Arthroplasty Register. We included patients operated with cemented bipolar HA and compared them to the most frequently used cemented THA with 28-mm head during 2011–2016. For survival analysis, we used both revision for all reasons and for dislocations as an endpoint. Cox proportional hazards models were used to analyse the influence of covariates (age groups, gender, surgical approaches and arthroplasty groups). Results: There were 1177 bipolar HA and 514 THA included in our study. 26 (2.2%) revisions had occurred among the bipolar HAs as compared to 25 (4.9%) among the THAs 1 year after surgery. The main reason for revision was dislocation. The unadjusted cumulative revision rate for any reason at 1 year after surgery was 2.4% for the bipolar HA group and 5.1% for the THA group ( p = 0.0054). Cox regression analysis showed that the use of bipolar HA, anterolateral approach and younger age groups had lower risk of revision for all reasons. Conclusion: Bipolar HA and anterolateral approach had a significantly lower overall 1-year risk of revision in femoral neck fracture patients as compared to THA with 28-mm femoral heads.