The Accuracy of Virtual Surgical Planning in Free Fibula Mandibular Reconstruction: Comparison of Planned and Final Results

Purpose The concept of virtual surgery uses surgical simulation rather than relying exclusively on intraoperative manual approximation of facial reconstruction. The purpose of this study was to evaluate the degree to which surgical outcomes in free fibula mandibular reconstructions planned with virtual surgery and carried out with prefabricated surgical plate templates and cutting guides correlated to the virtual surgical plan in a series of 11 patients. Materials and Methods This retrospective study evaluated 11 consecutive patients (6 males and 5 females) with an average age of 50.73 years (range, 23-72 years) who required mandibular reconstruction for aggressive benign or malignant disease with a free fibula osseomyocutaneous flap at Emory University Hospital (Atlanta, GA) between January 1, 2009 and December 31, 2009. In each case, a high-resolution helical computed tomography (CT) scan of the maxillofacial region and mandible was obtained prior to surgery. The CT data was sent on a CD to a modeling company (Medical Modeling Inc, Golden, CO). The scans were then converted into 3-dimensional models of the maxillofacial skeleton utilizing both automatic and manual segmentation techniques in the SurgiCase CMF software (Materialise NV, Leuven, Belgium). A virtual surgery planning session was held via a Web meeting between the surgeons and the modeling company, at which the resection planes of the mandible, positioning of the plate, and fibula lengths/osteotomy angles were established. The surgery was then carried out using prefabricated cutting guides and manual bending of a reconstruction plate using a prefabricated plate template. A postoperative CT scan of each patient was obtained within the first 7 postoperative days on the same scanner. Three-dimensional computer models of the final reconstruction were obtained for comparison with the preoperative virtual plan. To make the desired comparisons, the 3-dimensional objects representing the postoperative surgical outcome were superimposed onto the preoperative virtual plan using manual alignment techniques. These objects were then compared by 1-to-1 magnification for measurements of fibular bone volume, location of mandibular osteotomies, location of fibular osteotomies, plate contour, plate position on fibula, and plate position on mandible. Comparison was made between the virtual and final plates with regard to contour and position through superimposition overlays of the 3-dimensional models that are re