大龄髋脱位儿童髋关节骨性形态研究及分析

目的应用CT的原始数据资料，结合反求工程软件．对大龄髋脱位儿童髋关节的病理形态结构做进一步的定量分析研究．以了解大龄髋脱位儿童髋关节的病理形态变化．探讨髋关节骨性形态的测量方法及意义．方法实验组共44个脱位髋，按照Tonnis分级标准分为2个亚组：半脱位组，共30个髋；全脱位组，共14个髋。单侧脱位患儿的“正常髋”为相对对照组．共41个髋。以Mimics软件读取CT原始数据．进行前处理．得到髋关节的点云数据，输入至反求工程软件Imageware中．对髋臼及股骨头的骨性关节面进行球面拟合．测定股骨头上下两部分对髋臼的匹配程度。结果大龄髋脱位儿童髋臼球面半径较乎、浅（全脱位组为27．470±6．299，半脱位组为24．340±2．637，对照组为21．710±1．975），股骨头发育小；3组中全脱位组表现得更加明显。实验组与对照组股骨头的上下两部分和骨性髋臼关节面匹配误差比较：全脱位组、半脱位组P〈0．001．对照组P〉0．05．显示股骨头上半部分对髋臼的匹配程度高于下半部分。结论髋脱位儿童股骨头上下两部分与髋臼的匹配差异提示了复位手术时股骨近端内翻截骨的必要性。适当的内翻截骨可以使匹配程度较高的股骨头上半部作为主要负重区。良好的球面匹配能获得良好的应力分布．从而减少或推迟骨关节炎的发生。

Study on the bone morphology of the hip dislocation in elder children

Objective To study the pathomorphological structure of hip dislocation in elder children with CT primal data and reverse engineering software,for further quantitative analysis in order to comprehend their pathomorphological change and explore the measurement technique of hip joint bone morphology. Methods A total of 44 hips were enrolled in the experiment, they were divided into 2 groups ：subluxation group （n = 30） and dislocation group （n = 14）. The ＂normal hip＂ of the unilateral hip dislocation cases were defined as control group（n = 41 ）. By using the Mimics software to read the CT primal data. The cloud data of the hip were obtained, and input into the reverse engineering software-imageware for spherical surface fitting of the acetabulum and femoral head. Then the match degree of two parts of the femoral head to acetabulum was measured. Results It was demonstrated that the acetabulum radius was flat and retuse in developmental dysplasia of the hip （in dislocation group 27.470 ± 6.299,subluxation group 24.340±2.637 ,control group 21.710 ± 1.975）. Comparison of the matching error of the acetabulum＇s osseous articular surface and the parts of femoral head between experimental group and control group：Dislocation group, subluxation group P 〈 0.001 ,control group P 〉 0.05. The match degree of upper haft part to acetabulum was higher than that of the lower half. Conclusion The match difference of the two parts of femoral head with the acetabulum has prompted that the varus osteotomy is very necessary in the reduction surgery. It can be allowed to cause the upper half which have the higher match degree to become mainly weight-bearing area. The good surface match can obtain the good stress distribution, thus to reduce or postpone the occurrence of the osteoarthritis.