Comparison of augmented reality and cutting guide technology in assisted harvesting of iliac crest grafts - A cadaver study.

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.