Options
2007
Journal Article
Titel
Intraoperative bone modelling for autologous bone grafting
Titel Supplements
Experimental evaluation and first clinical application
Abstract
For the reconstruction of a mandibular defect after tumour or trauma, a vascularized bone graft is taken from the iliac crest. In order to facilitate the healing process and to achieve a functional and aesthetic outcome, the geometry of the transplant has to be similar to the defect. We present a system that uses intraoperative tactile scanning to acquire the geometry of defect and donor site. If the tumour had been resected in a previous operation, its geometry has to be reconstructed by interpolating the remaining pieces of the mandible. The presented system uses the definition of two cut surfaces and the connecting path in order to construct a smooth interpolation. The accuracy of this interpolation was measured using a plastic replica of a human mandible where a piece had been cut out and bridged with a bone plate. The resected piece was scanned for reference using a laser surface scanner. The mean distance between the reconstructed cut surface and the reference was -2.17 mm. This distance includes the gap that is introduced by the saw (blade thickness 0.7 mm). The system was integrated into a navigation system and certified according to the European medical device directive. A patient with a large defect in the left mandible could be treated successfully using this device. The defect was reconstructed without the need for an additional adjustment of the bone graft.