Correlation between the stress shielding and clinical outcome after total hip arthroplasty with extensive porous coated stem

초록

Introduction: Excellent results of extensive porous coated stem in bone ingrowth have already proved. However, a lot of surgeons worry about proximal femoral bone loss from stress shielding. There is controversy that the stress shielding of proximal femur may affect the clinical outcome of total hip arthroplasty with extensive porous coated stem. Purpose: This study is to investigate the change of bone mineral density of proximal femur and the correlation between the stress shielding and clinical outcome after total hip arthroplasty with extensive porous coated stem. Material & Method : This retrospective study was performed on 51 patients who had had a unilateral primary total hip arthroplasties with use of the extensive porous coated stem. The contralateral normal femur of each patient was used as control. The dual energy xray absorptiometry (DEXA) was used to quantify the periprosthetic bone mineral contents for each region of both sides. The clinical outcome was estimated by using Harris hip scores (HHS). Results : There was no difference between bone mineral density of periprosthetic bones and that of control sides. The changes of periprosthetic bone mineral density were decreased all seven Gruen region. Especially, in region 1 and 2, bone mineral density was decreased more than other region. However HHS and pain had no relevance to the change of bone mineral density (p=0.385). Conculusion : The changes of periprosthetic bone mineral density compare to the contralateral normal femur were significant all region(p<0.05). However the stress shielding of proximal femur do not affect the clinical outcome of total hip arthroplasty with extensive porous coated stem.