The Influence Of Restoring Femoral Offset On The Function Of Hip After Total Hip Arthroplasty

BackgroundThe total hip arthroplasty which has been widely used all over the world is the most effective way to treat hip pain and dysfunction caused by end-stage hip disease.It can not only effectively relieve pain,restore limb function,but also improve the quality of patient’s life.In recent years,with the growing proportion of patients undergoing THA surgery,the incidence of postoperative complications is also increasing which usually has direct or indirect effects on the recovery of hip function after operation.Femoral offset is one of the important factors of affecting the normal anatomy structure of the hip joint and soft tissue biomechanical balance in THA surgery,which has important clinical significance of reconstructing the hip joint function,maintaining joint stability and reducing the wear degree of prosthesis and postoperative complications.More and more orthopaedic surgeons have begun to pay attention to the restoration of the femoral offset during the operation.ObjectiveTo investigate the influence on the function of hip whether the femoral offset was restored or not during the THA surgery and factors influencing the reconstruction of femoral offset in the total hip arthroplasty.MethodsAccording to the inclusion and exclusion criteria,the clinical data of seventy-six patients underwent unilateral the total hip arthroplasty(The contralateral side is normal hip joint)in the First Affiliated Hospital of Xinxiang Medical University from January2016 to June 2017 were retrospectively analyzed in this study.Rechecking the positive X-ray film of bilateral hip joint 1 month,2 months,3 months and 6 months after operation and conducting a follow-up.If the difference value of the femoral offset between the operative side and the contralateral side is within 4 mm,the patients were divided into the reconstructive group,and the rest of the patients were treated as the control group.The follow-up data were all complete and there were 54 cases in the reconstruction group and22 cases in the control group in this clinical study.Then to analyze the relationship between femoral offset and the abductor lever arm,Harris scores,the range of motion of hip,the full length of the two legs,the acetabular abduction angle and factors of affecting restoration of femoral offset.Results1.There was no significant difference in the abductor lever arm,Harris scores and the range of motion of hip between the two groups before operation(P>0.05).2.The abductor lever arm,Harris scores and the range of motion of hip in both groups in the last postoperative follow-up were significantly higher than those before operation(P<0.05).3.The abductor lever arm,Harris scores and the range of motion of hip in the reconstruction group in the last postoperative follow-up were significantly higher than those in the control group(P<0.05),besides,there was a significantly positive correlation between the femoral offset and the abductor lever arm,Harris scores and the range of motion of hip within a certain range(r=0.549,P<0.001;r=0.341,P<0.001;r=0.427,P<0.001).4.The percentage of the patient with equal length of the two legs after operation in the reconstruction group was significantly higher than that in the control group(χ~2=16.32,P<0.005).5.There was no significant difference in acetabular abduction angle between the two groups before and after operation(P>0.05).ConclusionRestoration of femoral offset in THA can enhance the abductor lever arm and the range of motion of hip,restore the length of the two legs,increase the stability of hip joint and improve the function of hip joint obviously.