Treatment of Femoral Neck Fractures: Unipolar Versus Bipolar Hemiarthroplasty at Sree Mookambika Institute of Medical Sciences

Fractures of neck of femur occur most commonly in elderly females and are uncommon in patients under the age of 60 years. When using a hemiarthroplasty there are two types of articulations of the prosthesis and the patient's acetabulum—unipolar or bipolar. There is inadequate evidence to support the choice between unipolar hemiarthroplasty and bipolar hemiarthroplasty.

To compare functional outcome of unipolar with bipolar prosthesis in cases of femoral neck fractures & to analyse the post operative outcome regarding hip function using Harris Hip Score.

This is prospective Study conducted between September 2014-September 2015 at department of Orthopaedics, Sree Mookambika Institute of Medical Sciences, Kulasekharam, district Kanyakumari. Patients of Femoral Neck Fractures, both male & female were included in the study. Those not willing were excluded. Sample size was calculated by Z²S(1-S)/d^{2 (4).} Total 60 patients were studied. Data was entered in Microsoft excel 2013 & analysed by SPSS trail version 20. Statistical test used descriptive statistics, correlation & Chi Square test. Institutional ethical committee clearance obtained.

Patients who had unipolar prostheses were comparatively older to those with bipolar prostheses (74.98 vs. 72.9, P<0.01). Male were 36% & females 64% were unipolar group. Whereas in bipolar group male were 19% & female 81%. Mean length hospital stay was similar in both groups (p>0.05).. 3.38% in the unipolar group presented with posterior dislocation. In unipolar, patients were 30% excellent and good score results 40%, while 25% maintained fair results and only 3% poor result. In Bipolar, 43.33% the patients maintained an excellent score, 35% had good score results, and 17% had fair and only 3% poor results.

Mean Harris Hip Score is 75.9 in unipolar & 84.61 in bipolar group. However, the difference from scores of unipolar patients was statistically insignificant (p>0.05). It was noted that patients of both groups had a negative correlation of age to score outcome regardless of sex and grade of fracture.

There appears to be statistical difference between the two groups that is bipolar being better in functional aspects. Incidence of complications was lower after bipolar hemiarthroplasty. The bipolar prosthesis seems to have the advantage of causing less acetabular wear than the unipolar prosthesis.