发育性髋关节脱位术后髋臼稳定性及矫形效果评估指标:三维CT对中心边缘角的量化测量

Three-dimensional quantitative computed tomography measurement of center-edge angle:acetabular stability and correction outcomes of hip after operation of dev elopmental dysplasia

目的:通过使用三维CT测量中心边缘角,定量化整体反映发育性髋关节脱位术后髋臼对股骨头的包容程度,为进一步实施功能矫正提供了精确、可信度较高的矫形设计依据。方法:利用三维CT对2003-06/11在第四军医大学西京医院骨科行手术治疗的34例单侧发育性髋关节脱位患者进行患侧术后与健侧中心边缘角的数据对比。男11例,女23例;年龄25～48个月,平均35个月;右侧14例,左侧20例。以三维CT确定股骨头中心点,以股骨头中心点垂线为轴线,旋转骨盆从0°(前侧髋臼缘)至90°(外侧髋臼缘)至180°(后侧髋臼缘),遂取到不同角度的相应截面。中心边缘角随髋臼缘每旋转10°测量1次。以中心边缘角为y轴,旋转角度为x轴,将测量数据制成图表,三维显示股骨头在髋臼窝的稳定情况和髋臼的发育情况,并量化表示。结果:按实际处理分析,34例进入3个月后随访,2例进入6个月及1年随访。0°～180°中心边缘角可直接反映股骨头在髋臼窝的稳定情况和髋臼的发育情况。外侧方中心边缘角均值为27°,95%可信区间为26.2°～27.9°。患者自身及患者间的误差变化分别为0.24°～4.53°和0.36°～5.58°。结论:三维CT测量中心边缘角,可全面反映发育性髋关节脱位术后股骨头在髋臼窝的稳定情况和髋臼的矫形效果,操作方法简便,并具有定量化的优点。

AIM:To quantitatively reflex the whole acetabular coverage of femoral head aft er operation of developmental dysplasia of hip(DDH) by three dimensional comput ed tomography(3DCT) measurement of center edge angle(CEA),so as to provide a ba sis for the functional correction of DDH with high precision and confidence leve l. METHODS:In the Department of Orthopaedics,Xijing Hospital,Fourth Military Medi cal University of Chinese PLA from June to November 2003,34 operated patients(ma le 11,female 23,at 25 to 48 months of age,mean of 35 months) with unilateral DDH (14 right sides and 20 left sides) were studied by using 3DCT to compare the dat a of CEAs between the affected sides and unaffected sides.3DCT was employed to d efine the geometric center of the femoral head,and then pelvis was rotated from 0°(anterior acetabular rim) to 90°(lateral acetabular rim) till to 180°(poste rior acetabular rim) using perpendicular line to the geometric center c of femor al head as the axis to get the corresponding sections at different angles.The CE As were measured at every 10°rotational increments around the acetabular rim.Th e measured data were made into graphs based on CEAs as y axes and rotational ang les as x axes.Stability of femoral head in acetabular fossa and development of a cetabulum were shown three dimensionally and expressed quantitatively. RESULTS:According to the intention management,34 cases were followed up for 3 months,and 2 cases were for 6 months and 1 year.CEAs from 0°to 180°could be sh own by the graphs,and the stability of femoral head in acetabular fossa and deve lopment of acetabulum were reflected directly.Mean normal CEA at the lateral rim was 27°with a 95%confidence interval of 26.2°to 27.9°.Error of inter and i ntra observer variability altered from 0.24°to 4.53°and from 0.36°to 5.58°r espectively. CONCLUSION:By employing the 3DCT measurements of CEAs,the stability of femoral head in acetabular fossa and correction outcomes of acetabulum are wholly refle cted after operation of DDH,and the operative procedure is simple and quantitati ve.