髋部结构分析在预测髋部脆性骨折的意义

Significance of hip structure analysis in the prediction of osteoporotic hip fracture

目的:探讨绝经后女性髋部结构几何力学参数在预测髋部脆性骨折危险性的临床意义。方法:选取216例绝经后女性,其中髋部骨折70例,正常对照组146例,测量股骨颈骨密度(FN-BMD),并用髋结构分析(HSA)软件在DXA扫描图像上分析得出髋结构几何力学参数,包括截面弯曲模量(SEM)、股骨颈横截面转动惯量(CSMI)、股骨颈横截面积(CSA)、屈曲应力比(BR)、股骨颈的皮质骨厚度(FNCT)及股骨颈干角(NSA)。利用ROC曲线分别分析其预测髋部骨折的效能。结果:FN-BMD、CSA、CSMI、FNCT、SEM在骨折组低于对照组(P<0.05),年龄、BR在骨折组高于对照组(P<0.05)。Logistic回归分析。年龄、BMI、FN-BMD、CSA、CSMI、FNCT、SEM、BR影响骨折发生的因素,得出FN-BMD、FNCT是判定绝经后妇女髋部脆性骨折最相关的危险因素。FN-BMD、CSA、CSMI、FNCT、SEM与年龄呈负相关,CSA、SEM与FN-BMD呈显著正相关(r分别为0.945、0.763,P<0.001),BR与FN-BMD呈显著负相关(r=-0.854,P<0.001),与年龄呈中度正相关。NSA角与年龄、绝经年龄、FN-BMD无相关性。通过ROC曲线分析髋关节几何学参数、FN-BMD及二者联合预测髋部骨折准确度,发现髋关节几何学参数联合FN-BMD的ROC曲线下面积为0.860(P=0.000),高于FN-BMD及髋关节几何学参数单独对脆性骨折的预测,并且曲线下面积差异存在统计学意义(P<0.05)。结论:(1)绝经后妇女的髋部骨强度不仅与骨量丢失相关,还与几何力学空间因素改变相关,故临床预测髋部脆性骨折应考虑FN-BMD及髋几何结构参数;(2)髋结构分析联合FN-BMD测定可以提高髋部脆性骨折风险的预测水平。

Objective To examine the clinical significance of geometric parameters of the hip （GPH） of post-menopausal women in the prediction of osteoporotic hip fractures.Methods The femoral neck bone mineral density （FN-BMD） of 216 postmenopausal women,including 70 cases of hip fractures and 146 cases of normal controls,were measured.Based on the dual energy X-ray absorptiometry （DXA） image of the hip,hip strength analysis （HSA） software was used to analyze the GPH,including section modulus （SEM）,cross-sectional moment of inertia （CSMI）,cross-sectional area （CSA）,buckling ratio （BR）,cortical thickness of femoral neck （FNCT） and neck shaft angle （NSA）.The performance of HAS software in the prediction of hip fractures was analyzed using receiver operator characteristics （ROC） curve.Results Fracture group showed significantly lower FN-BMD,CSA,CSMI,FNCT,SEM （P〈0.05）,older age,and significantly higher BR than control group （P〈0.05）.The logistic regression analysis of the factors affecting the fracture incidence （including age,BMI,FN-BMD,CSA,CSMI,FNCT,SEM and BR） confirmed that FN-BMD and FNCT were the most important risk factors related to the hip fracture incidence of post-menopausal women.FN-BMD,CSA,CSMI,FNCT,SEM were negatively correlated with age,while CSA,SEM were positively correlated with FN-BMD （r=0.945 and 0.763,respectively;P〈0.001）;BR was negatively correlated with FN-BMD （r=-0.854,P〈0.001）,but moderately positively with age;neck shaft angle didn＆#39;t showed any correction with FN-BMD,age and age at menopause.The area under ROC curve for the logistic regression probability model incorporating GPH and FN-BMD was 0.860,larger than that predicted by GPH and FN-BMD,separately （P=-0.000）,and the differences in the area under ROC curve were statistically significant （P〈0.05）.Conclusion The bone strength of the hip in post-menopausal women is not only influenced by bone loss,but also by the changes of geometric structure of the hip,therefore both the GPH and FN-BMD should be considered in the prediction of fragility fracture of the hip in order to reduce the fragility fracture incidence of the hip.