Mimics软件三维重建股骨头坏死模型模拟髓芯减压治疗早期股骨头坏死

Three-dimensional reconstruction of femoral head necrosis model and simulation of core decompression in early stage treatment by Mimics software

目的通过计算机模拟髓芯减压手术,为临床精准髓芯减压提供理论基础。方法将早期股骨头坏死病例的髋关节CT扫描数据导入Mimics10.01软件,三维重建病变股骨头及坏死病灶。根据坏死灶在三维空间X、Y、Z轴的最大及最小径线距离计算坏死灶体积、表面积,以股骨头中心为参照立体定位坏死灶。在计算机软件Mimics MedCAD模块中寻求完全清除坏死病灶所需的最小减压体积,并计算最小减压体积和最小减压体积占股骨头体积的百分比。设计最佳髓芯减压通道,模拟髓芯减压术,彻底清除病变坏死灶。结果利用Mimics软件重建病变股骨头模型并实现三维测量坏死病灶,坏死病灶体积为2177.09mm^3、表面积为1054.44mm^2。以股骨头中心为参照原点立体定位坏死灶,坏死病灶坐标为(-3.0985mm,-11.4060mm,-1.7223mm);设计最佳髓芯减压通道并测量其仰角及前倾角为:(1)仰角125.82°、前倾角25°;(2)仰角123.61°、前倾角29.6°。以计算出的最小减压体积4379.16mm3为参数,在Mimics软件中模拟髓芯减压,完全清除坏死病灶。结论通过Mimics软件模拟髓芯减压,可以使术者在术前更清楚的了解病变坏死灶的信息如体积、表面积、空间的位置,术前对髓芯减压手术进行评估,术后对股骨头塌陷进行预测;可以实现虚拟精准髓芯减压治疗早期股骨头坏死,为进一步实现实体手术提供理论基础。

Objective To provide a theoretical basis for the precise core decompression surgery by computer simulation. Methods CT Dicom format image of one case of osteonecrosis of the femoral head （ONFH） was imported into Mimics 10. 01 for three-dimensional （3-D） reconstruction of ONFH and the osteonecrosis lesions. According to the maxium and minus diameters of osteonecrosis lesions in 3-D space （discribed by X, Y, Z axes）, the volume and surface area of osteonecrosis were calculated, and the osteonecrosis was loscated using the center of femoral head as a reference. The minimum decompression volume for complete removal of necrotic lesions and its percentage in femoral head were all caculated by Mimics MedCAD module. The best core decompression channel was designed to simulate core decompression for complete removal of osteonecrotic lesions. Results Mimics software reconstructed the femoral head necrosis model and three-dimensionally measured necrotic lesions. The necrotic lesion volume was 2177.09 mm3, and the surface area was 1054.44 mm2. The osteonecrosis was located with the reference of the femoral head center, and the coordinates of necrotic lesions were （ - 3. 0985 mm at X axis, - 11. 4060 mm at Y axis, - 1. 7223 mm at Z axis）. The best core decompression channel was designed and its elevation angle and anteversion angles were as follows ： （ 1 ） elevation angle = 125.82°,anteversion angle = 25° ; （ 2 ） elevation angle = 123. 61°, anteversion angle = 29.6°. The minimum decompression volume was 4379. 16 mm3 , and the simulation of complete removal for necrotic lesions was accomplished by Mimics software. Conclusions Simulation of core decompression by Mimics software can provide a clearer understanding information such as volume, surface area, and location of necrosis lesion; it can also help in preoperative assessment of core decompression surgery, and predicting the postoperative collapse of femoral head. Simulation of precise core decompression for osteonecrosis of the hip in early stage can be achieved which may provide a theoretical basis for the further surgery.