Comment to “A technique for frameless stereotaxy and placement of transarticular screws for atlanto-axial instability in rheumatoid arthritis” by C. Wigfield and C. Bolger

Abstract

comes a common procedure, we want to have a “super-vision” that enables us to see the inside morphology of the vertebra and the position of screws within it. A technique for frameless stereotaxy developed with advances in computer technology can give us such a “super-vision”. Several surgical navigation systems for lumbar pedicle screwing have already been used clinically, and the usefulness of these systems has been reported. This paper reported the experience of using a technique for frameless stereotaxy in the cervical (atlantoaxial) region, and the authors make the case for the usefulness of the technique, particularly for screwing in the atlas, based on clinical evaluation. However, the usefulness of a technique for frameless stereotaxy in an anatomically complex area should be assessed multiphasically. First of all, the accuracy of a navigation system should be validated. The accuracy of the infrared camera, the registration method, surgical tools and surgical technique all affect the total accuracy of the system. The accuracy of registration varies at each level, and the accuracy of the system used in this study in the cervical region has not yet been disclosed. Of course the final phase of assessment of a system is clinical assessment such as this paper. However, the assessment should be made using more accurate evaluation methods. REVIEWER’S COMMENT Eur Spine J (2001) 10 :269 DOI 10.1007/s005860100247