Design Of A System Of Preparing The Pilot Hole Of Pedicle Screw In The Lower Thoracic And Lumbar Spine And Its Experimental Study

[Background] Pedicle screw placement is a commonly used technique in the field of spinal surgery for procedures requiring spinal stabilization and deformity correction. However, Pedicle screws are reportedly misplaced at a high rate of 20% to 40%. Transpedicular screw placement is associated with complications including pedicle fracture, and temporary or permanent neurologic injury. The accuracy with which such instrumentation can be placed is constantly under study.[Objective] The objective of the study was to design a system of preparing the pilot hole of pedicle screw placement and to evaluate the accuracy of this device in comparison with techniques commonly used for pedicle cannulation.[Methods] Seven spine specimens were cleaned of muscle and overlying soft tissue. These specimens included T10～L5. Preoperative anteroposterior and lateral radiographs were taken and inspected to rule out underlying osseous pathology or deformity. The entry site for each pedicle was identified using anatomic landmarks based on estimation of the pedicle projection dorsally, our routine method in clinical practice. For each spine specimen, the pedicles of one side were cannulated with the conventional placement technique using Kirschner wire, then were placed pedicle screws. For the other side of each spine specimen, the pedicles were cannulated with the system of preparing the pilot hole of...