Unipolar versus bipolar hemiarthroplasty for hip fractures in patients aged 90 years or older: A bi-centre study comparing 209 patients

Abstract

Background: This study aimed to evaluate the outcome of unipolar and bipolar hemiarthroplasty to treat hip fractures in patients aged ≥ 90 years.

Methods: We conducted this study from 2007 to 2018 based on the electronic databases of two hospitals. Patients aged ≥ 90 years, treated for Arbeitsgemeinschaft Osteosynthese 31-B3 type fractures, were included. One hospital conducted the treatment only with unipolar prostheses; the other hospital used only bipolar prostheses. We assessed 23 peri‑ and postoperative variables including any revision, dislocation, and survival. The follow-up was completed after a minimum of 2 years postoperatively. At follow-up, the functional status was evaluated via telephone using the Parker score for every living patient.

Results: One-hundred unipolar prostheses, and 109 bipolar prostheses were examined. The patients' mean age was 92.9 years (range 90-102). Dementia was differently distributed between the groups (p < 0.001), with a lower survival risk (Odds Ratio 1.908; Confidence Interval 1.392 - 2.615; log rank <0.001). Based on this result, unipolar demonstrated significantly higher mortality rates compared with bipolar prostheses (log rank < 0.001). No effects were found for dislocation, revision and overall complication rate. At follow-up, 37 patients were available for functional status. The mean Parker score was 3.7 (range 0-9), with no effect.

Conclusions: Intracapsular hip fractures in patients aged ≥ 90 years can be treated with unipolar or bipolar hemiarthroplasty. The type of prostheses did not influence dislocation, revision, general complication, or functional status. The groups were significantly affected by dementia, a risk factor for shorter survival.

Keywords: Bi-centre study; Bipolar hemiarthroplasty; Geriatric patients; Intracapsular hip fracture; Outcome; Unipolar hemiarthroplasty.