股骨近端骨密度定量CT测量及其在骨折手术前评估的作用

Measurement of bone mineral density of the proximal femur with quantitative computed tomography and its role of assessment before the surgical treatment of fractures

目的探讨定量CT(quantitative computed tomography,QCT)测量股骨近端的松质骨骨矿物质密度(bone mineral density,BMD)对股骨近端内固定物头钉的选择的指导价值。方法选择2011年1月至2011年12月,我院收治的50例股骨颈骨折或股骨粗隆间骨折患者作为骨折组,其中男23例,女27例,年龄17~94(63.8±16.3)岁;招募75位年龄匹配的健康受试者作为健康组,其中男18例,女57例,年龄23~76(61.2±10.4)岁。使用QCT分别对骨折组健侧和健康组双侧股骨近端的不同兴趣区域内的BMD进行测量和分析。结果骨折组健侧股骨头、股骨颈及粗隆部的骨密度分别为(153.0±37.6)mg/cm^3、(24.9±39.7)mg/cm^3、(26.6±30.6)mg/cm^3,健康组(左侧股骨近端)股骨头、股骨颈及粗隆部的骨密度分别为(220.2±46.1)mg/cm^3、(74.8±49.1)mg/cm^3、(70.8±41.3)mg/cm^3,骨折组各部分骨密度均低于健康组,差异有统计学意义(P<0.05)。股骨头与股骨颈和股骨粗隆部的骨密度下降的平均值不平行。结论骨质疏松是股骨近端骨折的危险因素;股骨粗隆部的骨密度并不能完全反映股骨头的骨密度;QCT是目前测量股骨头骨密度的惟一方法;术前使用QCT评估股骨头的BMD对于内固定物头钉的正确选择提供了依据。

Objective To investigate the potential value of the measurement of the cancellous bone mineral density （ BMD ） of the proximal femur by quantitative computed tomography （ QCT ） in the choice of adequate head screws in the management of proximal femur fractures.Methods A total of 50 patients with femoral neck or intertrochanteric fractures who were adopted from January 2011 to December 2011 were studied as the fracture group, including 23 males and 27 females. Their average age was （ 63.8±16.3 ） years old （ range： 17-94 years ）. Other 75 age-sex matched and healthy patients were treated as the healthy group, including 18 males and 57 females. Their average age was （ 61.2±10.4 ） years old （ range： 23-76 years ）. The BMD in different regions of interest （ ROI ） of the proximal femur were measured and analyzed by QCT for uninjured sides of the fracture group and bilateral sides of the healthy group.Results The BMD of the femoral head, femoral neck and trochanter in the fracture group were （ 153.0± 37.6 ） mg/cm3, （ 24.9±39.7 ） mg/cm3 and （ 26.6±30.6 ） mg/cm3 respectively, which were obviously lower than （ 220.2± 46.1 ） mg/cm3, （ 74.8±49.1 ） mg/cm3, （ 70.8±41.3 ） mg/cm3 in the healthy group. And the differences between them were statistically signiifcant （P〈0.05 ）. It was noticed that the decrease of BMD of the femoral head was not parallel with that of the neck and trochanter on average.Conclusions Osteoporosis is a risk factor for proximal femoral fractures, and the BMD of the femoral trochanter sometimes can’t fully relfect that of femoral head. So far, QCT is the only way to assess the BMD of the femoral head. Thus, the preoperative QCT assessment of the BMD of the femoral head is quite helpful in the choice of proper head screws of the implants.