TO EVALUATE EFFECT OF HORIZONTAL HIP OFFSET AND LEG LENGTH RECONSTRUCTION ON FUNCTIONAL OUTCOME OF TOTAL HIP REPLACEMENT

Background: For total hip replacement besides long term durability a optimal postoperative functional outcome is essential.so aim of this study was to determine the combined influence of hip geometry reconstruction on the clinical outcome following primary total hip replacement for unilateral osteoarthritis. Methods: A hospital based prospective study was carried out on 60 cases of unilateral osteoarthritis with normal contralateral hip. We prospectively assessed the clinical outcome and radiographic parameters for hip geometry reconstruction using validated measurements for the operated hip compared to the contralateral native hip with primary unilateral THA. The correlation of reconstruction parameters was investigated using a multivariate polynomial regression model for the dependent variable ?HHS (difference between the Harris hip scores preoperatively and 6 months postoperatively). Target zones for hip reconstruction were investigated for an association with superior clinical outcome. Results: The regression model demonstrated a significant correlation for the ?HHS and both hip offset (HO) reconstruction and leg length difference. Patients with accurate to slightly increased HO reconstruction combined with balanced leg length demonstrated a significantly higher ?HHS than patients outside this zone. Conclusion: HO and leg length reconstruction demonstrated an additive effect on clinical outcome and surgeons should aim for high accuracy in the reconstruction of both factor. Keyword: Hip offset, total hip arthoplasty, harris hip score