Design and implementation of deformation algorithms for computer assisted orthopedic surgery: application to virtual implant database and preliminary results

In cranio-maxillofacial and in trauma surgery while making osteosynthesis the surgeons want to reposition bone fractures and make fixation using implants and fixations devices. These devices need to be bent during surgery or prior surgery to fit geometrical boundary conditions defined by the individual anatomy of the patient. In clinical routine, surgeons must frequently repeat several times the "bend and try" process until they get the best fitting. This process often requires up to twenty minutes for a single osteosynthesis plate. A realistic deformation algorithm is then a pre-requisite to a computer-aided planning system which aims to help surgeons to optimally pre-bend the implant in respect to an individual patient bone structure. It has been shown that computer assisted planning system for bendable implant improves the results and operation outcome: shorter operation time, more accuracy, less post-operative implant failure, etc. This paper presents our preliminary results on implementing different types of deformation algorithms in the context of computer assisted orthopedic surgery