基于三维CT重建的计算机模拟技术在伯尔尼髋臼周围截骨术中的应用

Computer simulation based on Three-Dimensional CT reconstruction in bernese periacetabular osteotomy

目的评估基于三维CT重建的计算机模拟设计在Bernese髋臼周围截骨术的术前评估、手术设计以及术后效果分析的可行性。方法从2004年7月至2006年4月，16例（18髋）的Bernese髋臼周围截骨术使用基于三维CT重建的计算机模拟技术。男1例（2髋），女15例（16髋）；手术时年龄为14-42岁，平均24岁。术前行髋关节螺旋CT扫描并进行三维重建，使用“Top View”技术及Azuma分级对股骨头覆盖程度进行评估。通过该程序对Bernese髋臼周围截骨术进行模拟操作，记录模拟手术中髋臼截骨块向外侧和前方旋转的角度，作为实际手术的参考。术后复查髋关节CT及三维重建对术后效果进行分析。结果18髋术前外侧CE角平均为2．94^o（-14^o-22^o），臼顶倾斜角平均为27．7^o（12^o-40^o），前方CE角平均为8．94^o（-10^o-18^o），Top View的股骨头覆盖率平均为63．5％（50％-77％）。术后平均外侧CE角为30．1^o（13^o-47^o），臼顶倾斜角平均为5．5^o（-13^o-18^o），前方CE角为26．9^o（15^o-38^o），Top View的股骨头覆盖面积平均为92．5％（84％-100％）。术后14髋（77．8％）的Azuma分级与模拟设计的分级相符，3髋前覆盖矫正过多，1髋前覆盖矫正稍不足。结论基于三维CT重建的计算机模拟技术能够直观、立体地再现髋臼发育不良的畸形特点，与二维图像可互为补充，通过模拟截骨操作可使术者了解合适的截骨位置和旋转角度，以指导实际的截骨手术。

Objective To evaluate the value of computer simulation technique based on three-dimensional CT reconstruction in Bernese periacetabular osteotomy for surgical planning and postoperative analysis. Methods Between July 2004 and April 2006, the computer simulation technique was used on 18 hips in 16 patients for Bernese periacetabular osteotomy, including 2 hips in 1 male, 16 hips in 15 female. The average age was 24 years （14-42 years）. All patients performed helical CT scan for the three-dimensional reconstruction. “Top View” technique and Azuma＇s grades were adopted to evaluate the coverage of the femoral head preoperatively and postoperatively. Using a special computer program to simulate Bernese periacetabular osteotomies. Results Preoperatively, the average lateral CE angle of 18 hips was 2.94^o（-14^o- 22^o）, the average acetabular roof obliquity was 27.7^o（12^o-40^o）, the average anterior CE angle was 8.94^o（- 10^o-18^o）, and the average coverage in top views was 63.5% （50%-77%）.The postoperative average lateral CE angle was 30.1^o（13^o-47^o）, the average acetabular roof obliquity was 5.5^o（-13^o-18^o）, the average anterior CE angle was 26.9^o（15^o-38^o）, and the average coverage in top views was 92.5%（84%-100%）. 14 of the 18 hips （77.8%） had achieved the same Azuma＇s grades according to the simulation, 3 hips were overcorrected anteriorly, 1 hip with mild undercorrection in anterior coverage. Conclusion The computer simulation technique based on three-dimensional CT reconstruction is a good supplement to two dimensional images, and it can help surgeons observe the acetabular deficiencies and morphic deformities directly. The simulated periacetabular osteotomy can be an applicable guide for the real surgery. With the development of computer navigation and assisted surgery systems, it will play an important role to improve the precision of the reorientation of the acetabular fragment, and consequently the surgical outcome.