title: Isthmus-guided cortical bone trajectory for pedicle screw insertion.
abstract: Herein is described cortical bone trajectory (CBT), a new path for pedicle screw insertion for lumbar vertebral fusion. Because the points of insertion are under the end of the inferior articular process, and because the screws are inserted toward the lateral side, there is less soft tissue development than with the conventional technique; the CBT technique therefore enables less invasive surgery than the conventional technique. However, it has some drawbacks. For example, in the original CBT approach, the points of insertion are in the vicinity of the end of the inferior articular process. Because this joint has been destroyed in many patients who have indications for intervertebral fusion surgery, it is sometimes difficult to use it as a reference point for screw insertion location. With severe lateral slippage, the screw insertion site can become significantly dislocated sideways, with possible resultant damaging to the spinal canal and/or nerve root. The CBT technique here involved inserting the screws while keeping clear of the intervertebral foramen with the assistance of side view X-ray fluoroscopy and using the end of the inferior articular process and the isthmus as points of reference for screw location.
authors.affiliation: Department of Neurosurgery, Osaka University Medical School, Osaka, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Iwatsuki
authors.forename: Toshiki
authors.initials: T
authors.lastname: Yoshimine
authors.forename: Yu-ichiro
authors.initials: Y
authors.lastname: Ohnishi
authors.forename: Kosi
authors.initials: K
authors.lastname: Ninomiya
authors.forename: Toshika
authors.initials: T
authors.lastname: Ohkawa
mesh_terms: D001863:Bone Screws; D005471:Fluoroscopy; D006801:Humans; D008159:Lumbar Vertebrae / Q000601:surgery*; D013123:Spinal Fusion / Q000295:instrumentation / Q000379:methods*; D013130:Spinal Stenosis / Q000000981:diagnostic imaging / Q000601:surgery; D014057:Tomography, X-Ray Computed
keywords: Cortical bone trajectory; Isthmus guide; Lumbar fusion