Background

Harvesting vascularized bone grafts with computer-assisted surgery represents the gold standard for mandibular reconstruction. However, current augmented reality (AR) approaches are limited to invasive marker fixation. This trial compared a markerless AR-guided real-time navigation with virtually planned and 3D printed cutting guides for harvesting iliac crest grafts.

Material and methods

Two commonly used iliac crest transplant configurations were virtually planned on 10 cadaver hips. Transplant harvest was performed with AR guidance and cutting guide technology. The harvested transplants were digitalized using cone beam CT. Deviations of angulation, distance and volume between the executed and planned osteotomies were measured.

Results

Both AR and cutting guides accurately rendered the virtually planned transplant volume. However, the cumulative osteotomy plane angulation differed significantly (p = 0.018) between AR (14.99 ± 11.69°) and the cutting guides (8.49 ± 5.42°). The cumulative osteotomy plane distance showed that AR-guided navigation had lower accuracy (2.65 ± 3.32 mm) than the cutting guides (1.47 ± 1.36 mm), although without significant difference.

Conclusion

This study demonstrated the clinical usability of markerless AR-guided navigation for harvesting iliac crest grafts. Further improvement of accuracy rates might bring clinical implementation closer to reality.

中文翻译：

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增强现实和切割引导技术在辅助收获髂嵴移植物中的比较——一项尸体研究

背景

通过计算机辅助手术采集血管化骨移植物是下颌骨重建的金标准。然而，当前的增强现实 (AR) 方法仅限于侵入性标记固定。该试验将无标记 AR 引导的实时导航与用于采集髂嵴移植物的虚拟计划和 3D 打印切割指南进行了比较。

材料与方法

两种常用的髂嵴移植配置实际上是计划在 10 具尸体臀部上进行的。采用 AR 引导和切割引导技术进行移植收获。使用锥形束 CT 对收获的移植物进行数字化。测量执行的和计划的截骨术之间的角度、距离和体积的偏差。

结果

AR 和切割指南都准确地呈现了虚拟计划的移植体积。然而， AR (14.99 ± 11.69°) 和切割导向器 (8.49 ± 5.42°)的累积截骨平面角度差异显着 ( p = 0.018)。累积截骨平面距离显示，AR 引导的导航精度 (2.65 ± 3.32 mm) 低于切割引导 (1.47 ± 1.36 mm)，但没有显着差异。

结论

这项研究证明了无标记 AR 引导导航用于采集髂嵴移植物的临床可用性。准确率的进一步提高可能会使临床实施更接近现实。