数字化定制桡骨小头假体并术前三维虚拟置换验证研究

VALIDATION STUDY ON PRECISION OF DIGITIZED CUSTOM-MADE RADIAL HEAD PROSTHESIS BY THREE-DIMENSIONAL VISUALIZATION OF VIRTUAL SURGERY

目的研究数字化定制桡骨小头假体的方法并术前三维虚拟置换验证假体匹配度。方法采用Speed Light 16排连续螺旋CT机对6名健康成年志愿者(男3名,女3名;年龄25～55岁,平均33岁)行双侧肘关节薄层扫描,扫描数据导入Mimics 10.0软件三维重建,生成左侧(健侧)桡骨近端镜像模拟右侧(患侧)并分割为头、颈部。桡骨小头经Geomagic Studio 12软件加厚1 mm模拟覆盖软骨面,逆向工程生成实体;采用Mimics 10.0软件测量工具获取桡骨颈段参数,用UG NX 8.0软件设计假体柄并装配头部实体。数字软件生成的6个右侧桡骨小头假体于UG NX 8.0软件中三维虚拟置换并验证假体匹配度。结果三维虚拟患侧桡骨小头置换验证6个基于健侧解剖的数字化定制假体,与原右侧桡骨小头形态学比较误差<1 mm,假体解剖匹配性良好。结论基于健侧桡骨近端解剖CT影像,应用数字骨科软件定制的患侧桡骨小头假体,经术前虚拟置换验证表明可供临床精确置换。

Objective To study digitize design of custom-made radial head prosthesis and to verify its matching precision by the surgery of preoperative three-dimensional （3-D） virtual replacement. Methods Six healthy adult volunteers （3 males and 3 females, aged 25-55 years with an average of 33 years） received slice scan of bilateral elbow by Speed Light 16-slice spiral CT. The CT Dicom data were imported into Mimics 10.0 software individually for 3-D reconstruction image, and the left proximal radial 3-D image was extracted, the mirror of the image was generated and it was split into 2 pieces： the head and the neck. The internal diameter and the length of the radial neck were obtained by Mimics 10.0 software measurement tools. In Geomagic Studio 12 software, the radial head was simulated to cover the cartilage surface （1 mm thickness） and generated to an entity. In UG NX 8.0 software, the stem of prosthesis was designed according to the parameters above and assembled head entity. Each custom-made prosthesis was performed and verified its matching precision by the surgery of preoperative 3-D virtual replacement. Results Comparing the morphology of 6 digitize custom-made prostheses with ipsilateral radial heads by the 3-D virtual surgery, the error was less than 1 mm. The radial head prosthesis design on basis of the contralateral anatomy was verified excellent matching. Condusion The 3-D virtual surgery test and the digitized custom-made radial head prosthesis will be available for clinical accurate replacement.