In elderly patients suffering from a displaced femoral neck fracture, a cemented hip arthroplasty (HA) has been shown to reduce the reoperation rate and give better hip function. When using an HA two types of prosthesis exsists- unipolar or bipolar. It is hypothesized that bipolar prostheses lead to better long-term functional outcomes with less complications. Aim of this study is to compare the results of unipolar (Austin Moore’s Prosthesis) and bipolar hemiarthroplasty done at our institution.
Materials & Methods: This is a randomized control trial including 100 patients with fracture neck of femur, equally divided into 2 groups of 50 each. Patients in Group-A were treated using unipolar Austin Moore’s Prosthesis (AMP) and in Group-B were treated using Bipolar prosthesis. Patients were assessed clinically based on Harris hip score, and radiologically for acetabular erosion according to the method described by Baker.
Results: 66% of patients with bipolar prosthesis reported minimal or no pain at follow-up compared to 65% of patients with Moore’s prosthesis. Hip function according to the HHS was similar at both follow-ups. Acetabular erosion was observed in 2 patients belonging to the Moore’s group but not in the bipolar group. Other complications were similar in both groups.
Discussion: Hemiarthroplasty, as an effective technique for displaced femoral neck fractures. Controversy has persisted for a long time regarding the use of bipolar versus unipolar prosthesis. The results of our study did not demonstrate any differences between the two groups. However, at a mean follow up of one year signs of acetabular erosion were more frequent after the unipolar HA, but this difference was not statistically significant.
Conclusion: This study suggests that Bipolar HA is associated with similar improvement in hip functionality, hip pain, and quality of life compared with Unipolar HA and that there are no significant differences between Bioplar HA and Unipolar HA at 1year follow up.