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.

A semi-automatic orthopedic implant management tool for Computer Assisted planning, navigation and simulation: from XML implant database to unified implant access interface.

Nowadays, Computer Assisted Orthopedic planning and navigation systems have been recognized as an important tool that helps surgeons. Various systems have been developed so far, but most of them use non-standard formalisms and techniques. As a result there are no standard concepts for implant and tool management or data formats to store information for use in 3D planning and navigation systems. We addressed these limitations and developed a practical and generic solution which brings benefits for surgeons, implant manufacturers and CAS application developers. We developed a virtual implant database containing geometrical as well as calibration information for orthopedic implants and instruments with a focus on Trauma. This database has been successfully tested with various applications in client/server mode. Nevertheless, the implant information is not static because periodically manufacturers revise implants, resulting in the removal of some implants and addition of new ones. To ease the implant management in respect to implant life cycle, we developed an implant management tool which helps end-users to manage their implants. Currently, this tool allows the addition of new implants, modification of existing ones, deletion of obsolete implants, export of a given implant and also creation of backups. Our implant management system has been successfully tested in the laboratory and gave very promising results. It makes it possible to fill the current existing gap between CAS system, implant manufacturers, hospitals and surgeons.

New orthopaedic implant management tool for computer-assisted planning, navigation, and simulation: from implant CAD files to a standardized XML-based implant database.

Computer-Assisted Orthopaedic Surgery (CAOS) has made much progress over the last 10 years. Navigation systems have been recognized as important tools that help surgeons, and various such systems have been developed. A disadvantage of these systems is that they use non-standard formalisms and techniques. As a result, there are no standard concepts for implant and tool management or data formats to store information for use in 3D planning and navigation. We addressed these limitations and developed a practical and generic solution that offers benefits for surgeons, implant manufacturers, and CAS application developers. We developed a virtual implant database containing geometrical as well as calibration information for orthopedic implants and instruments, with a focus on trauma. This database has been successfully tested for various applications in the client/server mode. The implant information is not static, however, because manufacturers periodically revise their implants, resulting in the deletion of some implants and the introduction of new ones. Tracking these continuous changes and keeping CAS systems up to date is a tedious task if done manually. This leads to additional costs for system development, and some errors are inevitably generated due to the huge amount of information that has to be processed. To ease management with respect to implant life cycle, we developed a tool to assist end-users (surgeons, hospitals, CAS system providers, and implant manufacturers) in managing their implants. Our system can be used for pre-operative planning and intra-operative navigation, and also for any surgical simulation involving orthopedic implants. Currently, this tool allows addition of new implants, modification of existing ones, deletion of obsolete implants, export of a given implant, and also creation of backups. Our implant management system has been successfully tested in the laboratory with very promising results. It makes it possible to fill the current gap that exists between the CAS system and implant manufacturers, hospitals, and surgeons.