There have been a number of developments in screw design and implantation techniques over recent years, including proposal of an alternative trajectory entitled as cortical bone trajectory (CBT). Cortical bone trajectory has been investigated in recent medical treatments as an alternative for screw fixation aimed at increasing purchase of pedicle screws in higher density bone. CBT screw insertion follows a lateral path in the transverse plane and caudocephalad path in the sagittal plane. This technique has been advocated because it is reportedly less invasive, improves screw−bone purchase and reduces neurovascular injury. Furthermore CBT pedicle screw fixation provides stabilization to multilevel lumbar segment with low-grade spondylolisthesis comparable to the standard trajectory pedicle screw construct. However, these claims have not been supported by robust clinical evidence. Recent investigations focus on evaluations of CBT as a pioneer method.
. Boucher HH. A method of spinal fusion. J Bone Joint Surg Br. 1959;41-b(2):248-59.
. Roy-Camille R, Saillant G, Berteaux D, Salgado V. Osteosynthesis of thoraco-lumbar spine fractures with metal plates screwed through the vertebral pedicles. Reconstruction surgery and traumatology.1976; 15:2-16.
. Magerl FP. Stabilization of the lower thoracic and lumbar spine with external skeletal fixation. Clin Orthop Relat Res. 1984;(189):125-41.
. Barber JW, Boden SD, Ganey T, Hutton WC. Biomechanical study of lumbar pedicle screws: does convergence affect axial pullout strength? J Spinal Disord. 1998;11(3):215-20.
. Cook SD, Salkeld SL, Whitecloud TS, 3rd, Barbera J. Biomechanical evaluation and preliminary clinical experience with an expansive pedicle screw design. J Spinal Disord. 2000;13(3):230-6.
. Cook SD, Salkeld SL, Stanley T, Faciane A, Miller SD. Biomechanical study of pedicle screw fixation in severely osteoporotic bone. Spine J. 2004;4(4):402-8.
. Roy-Camille R. Posterior screw plate fixation in thoracolumbar injuries. Instr Course Lect. 1992;41:157-63.
. Inceoglu S, Montgomery WH, Jr., St Clair S, McLain RF. Pedicle screw insertion angle and pullout strength: comparison of 2 proposed strategies. J Neurosurg Spine. 2011;14(5):670-6
. Hart RA, Hansen BL, Shea M, Hsu F, Anderson GJ. Pedicle screw placement in the thoracic spine: a comparison of image-guided and manual techniques in cadavers. Spine (Phila Pa 1976), 2005, 30: E326–E331.
. Matsukawa K, Yato Y, Kato T, Imabayashi H, Asazuma T, Nemoto K. In vivo analysis of insertional torque during pedicle screwing using cortical bone trajectory technique. Spine (Phila Pa 1976), 2014, 39: E240–E245.
. Laine T, Lund T, Ylikoski M, Lohikoski J, Schlenzka D. Accuracy of pedicle screw insertion with and without computer assistance: a randomised controlled clinical study in 100 consecutive patients. Eur Spine J. 2000; 9: 235–240.
. Balderston RA, Winter RB, Moe JH, Bradford DS, Lonstein JE. Fusion to the sacrum for nonparalytic scoliosis in the adult. pine (Phila Pa 1976) 11:824–829, 1986
. Patel SS, Cheng WK, Danisa OA. Early complications after instrumentation of the lumbar spine using cortical bone trajectory technique. J Clin Neurosci. 2016 Feb;24:63-7.
Phan K, Hogan J, Maharaj M, Mobbs RJ. Cortical Bone Trajectory for Lumbar Pedicle Screw Placement: A Review of Published Reports. Orthop Surg. 2015 Aug;7(3):213-21.
Santoni BG, Hynes RA, McGilvray KC, Rodriguez-Canessa G, Lyons AS, Henson MA. Cortical bone trajectory for lumbar pedicle screws. Spine J. 2009 May;9(5):366-73.
Cheng WK, İnceoğlu S. Cortical and Standard Trajectory Pedicle Screw Fixation Techniques in Stabilizing Multisegment Lumbar Spine with Low Grade Spondylolisthesis. Int J Spine Surg. 2015 Aug 31;9:46.
Mobbs RJ. The "medio-latero-superior trajectory technique": an alternative cortical trajectory for pedicle fixation. Orthop Surg. 2013 Feb;5(1):56-9.
Matsukawa K, Yato Y, Kato T, Imabayashi H, Asazuma T, Nemoto K. Cortical bone trajectory for lumbosacral fixation: penetrating S-1 endplate screw technique: technical note. J Neurosurg Spine. 2014 Aug;21(2):203-9.