Instrumentation Report An endoscopic pedicle probe: Preliminary development

Abstract

Insertion ofpedicle screws in the thoracolumbar spine can be challenging. Incorrect placement can lead to a failure. of fusion or to significant neurologic morbidity. Recently, techniques utilizing intraoperative monitoring and stereotaxis have been developed to achieve proper screw placement. While these techniques may be accurate, they are expensive and may reqLiire additional operating room personnel. We have developed an endoscopic pedicle probe for placement of pedicle screws that may overcome some of these limitations. A small 1.2 mm endoscope was adapted to fit within a hollow pedicle probe. Irrigation was provided via a separate channel within the endoscope. Images from the probe were displayed. both 6n a monitor screen and on a heads up display. The endoscopic pfobe was used to probe 3.6 sawbqne andc22 cadaver thoracolumbar pedicles. After cannulation each specimen was examined to assess Sanvisualized pedicle perforation. In sawbones, perforation was visualized endoscopically in 3 pedicles (8%) with no further perforations found on later direct examination. In cadavers the corticar ca(1cellous interface Was adequately visualized and no perforations occurred. These preliminary results suggest that the endoscopic probe may have utility in the placement of thoracolumbar pedicle screws. [Neurol Res 1997; 19: 657-661]