骨矿改变在人工全髋关节置换术的监测

目的：研究人工全髋关节置换术后髋周骨矿含量的改变。方法：对骨水泥型人工全髋关节置换的25例27髋，在术后不同时段用DEXA测定髋周5个区域的骨矿含量，并与其各自合适的对照作配对样本t检验。结果：术后1个月内（平均23d)测定组显示第4区骨矿量显著增加（P＜0．05）；术后4－6月（平均4．4月）和7－12月测定组显示5个区骨矿量无显著增减（P＞0．05）；术后14－49月（平均27．4月）测定组显示第2区和第5区骨矿量显著降低（P＜0．05）；第1区也有明显降低趋势（P＝0．064）。结论：骨水泥型人工全髋置入后髋周承重部位骨矿量在12月内改变不大；术后约2年在髋臼周围和股骨小粗隆部骨矿明显丢失，与置入假体后产生应力遮挡可能有关。

Assessment of Bone Mineral Changes after Total Hip Arthroplasty

Objective:To study periprosthetic mineral changes after cemented total hip arthroplasty(THA).Methods:Selecting 5 regions of interesting(ROI) in periprosthetic bone,27 hips of 25 cases were examined by dual X ray absorptiometry(DEXA) after THA to determine the bone mineral density(BMD) of these 5 ROIs,the bone mineral changes compared with the BMD of contrast groups,and were evaluated through paired sample t test.Result:The BMD of 4th ROI had significant increase( P <0.05) within 1 month after THA;the BMD of all 5 ROIs had no significant differences during 4th to 12th months;the BMD of 2nd and 5th ROIs had significant decrease( P <0.05) ,and the BMD of 1st ROI tended to become lower( P =0.064) during 14th to 49th month(average 27.4 months).Conclusion:The BMD of periprosthetic loading area were no significant change within 12 months after cemented THA;the BMD of periacetabular area and lesser trachander area were significant decrease at about postoperative 2 years,this phenomenon may be due to the stress shielding after THA.