Bipolar or Unipolar Hemiarthroplasty after Femoral Neck Fracture in the Geriatric Population

Abstract

Background: The choice of prosthesis in hemiarthroplasty is controversial for geriatric patients after femoral neck fracture. We hypothesised that selection criteria for unipolar or bipolar prostheses could be constructed based on factors affecting mortality. Aims: The aims of this retrospective study were: (1) to determine the factors affecting mortality of femoral neck fracture patients ≥65 years of age; (2) to compare patient mortality rates, radiological findings, and functional outcomes according to prosthesis type (unipolar or bipolar); and (3) to evaluate the persistence of inner bearing mobility of bipolar prostheses. Study Design: Retrospective comparative study. Methods: In total, 144 patients operated for hemiarthroplasty and aged ≥65 were included. We classified the patients into either unipolar or bipolar prosthesis groups. To reveal factors that affected mortality, age, sex, delay in surgery, and American Society of Anesthesiologists score were obtained from folders. Barthel Daily Living, Harris hip, and acetabular erosion scores were calculated and bipolar head movement was analysed for live patients. Results: One-year mortality was 31.94%. Age ≥75 (p=0.029), male sex (p=0.048), and delay in surgery ≥6 (p=0.004) were the patient characteristics that were related to increased mortality. There were no significant differences in sex, age, American Society of Anesthesiologists score, delay in surgery, mortality, or Barthel, Harris, acetabulum scores between the two groups. Twenty patients from each group were admitted for last follow-up. Bipolar head movement was preserved for 33.3% of patients. They were inactive patients with low Barthel and Harris scores. Conclusion: Although bipolar head movement was preserved in inactive patients, we suppose that this conferred no advantage to these patients, who could hardly walk. In this study, male patients, those aged ≥75 years, and those operated at ≥6 days had an increased risk of mortality. Also, although not significant in multivariate analysis, high American Society of Anesthesiologists score (≥3) was related to increased mortality. Considering that one of three patients died during the first postoperative year, we think that these patients should be operated as soon as possible, and expensive bipolar prostheses must be used selectively in regard to patient characteristics.

Keywords

• Femoral neck fracture
• mortality
• hemiarthroplasty