Principles of computer-assisted arthroscopy of the temporomandibular jointwith optoelectronic tracking technology

Purpose. This preliminary clinical study evaluated the applicability, accur acy, and benefits of computer-assisted arthroscopy of the temporomandibular joint (TMJ) with optoelectronic tracking technology. Material and methods. A hybrid of reality and virtual reality is built as a composite-reality environment by extracting 3-dimensional anatomical struc tures through use of computed tomography, magnetic resonance imaging, radio graphy, and other types of imaging procedures commonly used in clinical pra xis. These various independent sources of imaging data of a particular pati ent can be combined with and complemented by complex graphic simulations. I ntraoperatively they are merged with online position data of surgical instr uments inside the patient's TMJ. This hybrid model of detailed anatomical s tructures, guidelines, and real-time instrument positions allows the surgeo n to accurately plan the arthroscopic intervention as well as to navigate e ffectively intraoperatively. Results. In the first 10 cases of computer-assisted TMJ arthroscopy, compos ite reality environment technology permitted the online visualization of TM J structures, puncture sites, instrument positions, and virtual pathways in relation to anatomical landmarks with high spatial accuracy (minimum, 0.0 mm; maximum, 2.5 mm; mean, 1.4 mm; SD, 0.6 mm) and high temporal resolution (100 ms). Past, present, and possible future instrument positions can be d isplayed. The application of computer-assisted arthroscopy caused little im mobility for either surgeon or patient. Conclusion. Even experienced surgeons profit from improved precision in the handling of the arthroscope; thus this technology was found to be particul arly useful in degenerative temporomandibular disorders and for triangulati on procedures.