计算机辅助下解剖型接骨板匹配性能量化评估的初步探索

A quantitative assessment index assisted by digital technology for matching performance of anatomically contoured plate

目的探讨一种新的利用计算机数字技术建立用于评估解剖型接骨板匹配性能的通用量化指标。方法收集2015年4月至2016年6月期间20例成年人的正常胫骨32排螺旋CT薄层扫描数据。男10例，女10例；年龄28～52岁，平均36．2岁。使用Mimicsl8．0软件对胫骨进行三维重建。将康力公司和通用公司的胫骨远端8孔解剖型接骨板进行数字化建模，抽取接骨板贴骨部分的曲面，在Rhino5．1软件中模拟手术操作将接骨板曲面放置于胫骨远端内侧的表面。测量接骨板与骨骼表面之间间隙的体积，除以接骨板的表面积，获得接骨板与骨骼表面之间的平均间隙，取平均间隙值的倒数作为匹配指数。使用3．maticResearch套件中的墙体厚度工具，将不同的间隙距离使用不同色彩标注其分布，从而在匹配指数和直观的色彩分布云图两方面对两种接骨板匹配性能进行比较。结果康力公司和通用公司的接骨板与骨骼之间的间隙体积分别平均为（3834±701）mm3和（7690±1503）mm3，间隙分别平均为（1．8±0．3）mm和（3．0±0．6）mm，匹配指数分别平均为0．56±0．10和0．34±0．06，康力公司的接骨板的匹配指数大于通用公司的接骨板，差异有统计学意义（t=10．402，P〈0．001）。同种接骨板对不同性别的骨骼匹配指数比较差异无统计学意义（P〉0．05）。通用公司的胫骨远端内侧板的红色区域面积更大且位置较为固定。结论该匹配性能量化指标简单且直观，可作为一种通用的量化指标对不同形态接骨板的匹配性能进行评估和比较，也可作为单个患者的术前选用接骨板的评估指标。

Objective To explore a new way assisted by digital technology to establish a quantitative index to assess the matching performance of anatomically contoured plate. Methods We collected the thin-slice CT data of 20 adults with normal tibias who had received 32-slice spiral CT scanning from April 2015 to June 2016. They were 10 males and 10 females, aged from 28 to 52 years （average, 36.2 years） . 3D reconstruction of the tibias was performed with Mimics 18.0. Two brands of 8-hole anatomically contoured plate for distal tibia （Kongli versus GE） were digitized. The curve of the plate facing the bone surface was extracted. The operational process of putting the plate curve on the medial surface of the distal tibia was simulated in Rhino 5.0. The volume of the gap between plate curve and bone surface was measured. The mean distance of the gap between plate cure and bone surface was figured out after the volume divided by the plate area. The inverse value of the mean distance of the gap was used as the index for matching performance. The wall thickness analyzing tool in 3-matic Research was used to mark the various thicknesses of the gap with different colors. The matching performances of the 2 brands of plate were assessed and compared according to the matching performance index and nephogram. Results Of the Kongli 8-hole distal tibial plate, the gap volume was 3,834 mm3 ± 701 mm3, the mean thickness 1.8 mm ± 0.3 ram, and the matching index 0.56 ± 0. 10. Of the GE 8-hole tibial plate, the gap volume was 7, 690 mm3± 1,503 mm3, the mean thickness 3.0 mm ± 0.6 mm, and the matching index 0.34± 0. 06. The significant difference in matching performance between the 2 kinds of plate favored the Kongli plate （ t = 10. 402, P 〈 0.01 ） . There were no significant differences in matching per- formance between different genders among the plates of the same brand （ P 〉 0. 05）. The nephogram showed a large fixed red area at the proximal part in the GE 8-hole tibial plate. Conclusions As this index for matching performance is simple and intuitive, it can be used to assess and compare the matching performances between different kinds of plates. It can be also used before operation to assess the matching performance of a specific plate for a specific patient to avoid mismatch because of individual differences.