Outcome of bipolar vs unipolar hemiarthroplasty in elderly: A systematic review

Background:Preference between bipolar hemiarthroplasty (BH) and unipolar hemiarthroplasty (UH) for displaced femoral neck fractures in elderly remains controversial. A systematic review was conducted to evaluate the differences in the outcome between BH and UH and arrive at a conclusion. Methods: A systematic literature search (up to April, 2019) was conducted by accessing Cochrane and PubMed data base to include RCTs comparing BH with UH for displaced femoral neck fractures. Authors independently analysed and extracted data. Complications and outcomes were recorded and analyzed. Results: A total of 9 RCTs consisting of1248 patients were indentified. At short term follow up(4 to 6 months), BH had better functional outcome with respect to hip function but in long term (after 1 year) results were similar in both groups. At short term follow up, complication like dislocation and reoperation were more in BH group where as in the long term acetabular erosion rate was higher in UH group. Other complications such as infection and mortality rates were similar in both groups. Conclusions: Based on the current evidence, BH is superior to UH with respect to acetabular erosion but UH is superior to BH with respect to dislocations and reoperation. Though follow up showed higher acetabular erosion rate in UH group, it did not affect Harris Hip score at final outcome(80.45% in bipolar and 78.52% in unipolar). UH is cost effective when compared to BH.