Tomographic Analysis of the Anatomical Parameters for the Insertion of Cortical Bone Screws^[*]

Abstract

Objective To study the parameters related to the insertion path of cortical screws and to describe this technique.

Methods Computed tomography (CT) scans of 30 patients, as well as the measurements from the L1 to the L5 vertebrae, were studied. A second observer evaluated ten randomly-selected exams. The parameters studied included the lateral angle (LA) and the screw diameter (SD) as axial variables, and the cranial angle (CA) and screw length (SL) as sagittal variables.

Results We studied 15 male patients (mean age: 31.33 years) and 15 female patients (mean age: 32.01 years). The LA varied between 13.8° and 20.89°, with a tendency to increase in the proximal to distal direction. The CA varied from 17.5° to 24.9°, with a tendency to decrease in the caudal direction. The SD ranged from 2.3 mm to 7.2 mm, with a tendency to increase as we progressed from proximal to distal. The SL varied from 19 mm to 45 mm, with a tendency to decrease as we proceeded from proximal (L1) to distal (L5). No statistical difference was observed between the genders or in the interobserver agreement regarding the values studied when comparing the sides.

Conclusion The path of insertion of the cortical screw shows a variation in different populations. Therefore, we recommend a preoperative imaging study to reduce the surgical risks related to the technique.

Keywords

spine - minimally invasive surgical procedures - bone screws

^* Study developed at Hospital das Clínicas de Ribeirão Preto, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, SP, Brazil.

Financial Support

There was no financial support from public, commercial, or non-profit sources.

Publication History

Received: 27 July 2020

Accepted: 11 February 2021

Article published online:
24 January 2022

• Referências

• 1 Cook SD, Barbera J, Rubi M, Salkeld SL, Whitecloud 3rd. TS. Lumbosacral fixation using expandable pedicle screws. an alternative in reoperation and osteoporosis. Spine J 2001; 1 (02) 109-114
• 2 Mobbs RJ. The “medio-latero-superior trajectory technique”: an alternative cortical trajectory for pedicle fixation. Orthop Surg 2013; 5 (01) 56-59
• 3 Phan K, Ramachandran V, Tran TM. et al. Systematic review of cortical bone trajectory versus pedicle screw techniques for lumbosacral spine fusion. J Spine Surg 2017; 3 (04) 679-688
• 4 Kojima K, Asamoto S, Kobayashi Y, Ishikawa M, Fukui Y. Cortical bone trajectory and traditional trajectory--a radiological evaluation of screw-bone contact. Acta Neurochir (Wien) 2015; 157 (07) 1173-1178
• 5 Mai HT, Mitchell SM, Hashmi SZ, Jenkins TJ, Patel AA, Hsu WK. Differences in bone mineral density of fixation points between lumbar cortical and traditional pedicle screws. Spine J 2016; 16 (07) 835-841
• 6 Zhang R, Gao H, Li H. et al. Differences in bone mineral density of trajectory between lumbar cortical and traditional pedicle screws. J Orthop Surg Res 2019; 14 (01) 128-135
• 7 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 (04) E240-E245
• 8 Matsukawa K, Yato Y, Imabayashi H, Hosogane N, Asazuma T, Nemoto K. Biomechanical evaluation of the fixation strength of lumbar pedicle screws using cortical bone trajectory: a finite element study. J Neurosurg Spine 2015; 23 (04) 471-478
• 9 Baluch DA, Patel AA, Lullo B. et al. Effect of physiological loads on cortical and traditional pedicle screw fixation. Spine (Phila Pa 1976) 2014; 39 (22) E1297-E1302
• 10 Matsukawa K, Yato Y, Nemoto O, Imabayashi H, Asazuma T, Nemoto K. Morphometric measurement of cortical bone trajectory for lumbar pedicle screw insertion using computed tomography. J Spinal Disord Tech 2013; 26 (06) E248-E253
• 11 Zhang H, Ajiboye RM, Shamie AN, Wu Q, Chen Q, Chen W. Morphometric measurement of the lumbosacral spine for minimally invasive cortical bone trajectory implant using computed tomography. Eur Spine J 2016; 25 (03) 870-876
• 12 Senoglu M, Karadag A, Kinali B, Bozkurt B, Middlebrooks EH, Grande AW. Cortical Bone Trajectory Screw for Lumbar Fixation: A Quantitative Anatomic and Morphometric Evaluation. World Neurosurg 2017; 103: 694-701
• 13 Hung CW, Wu MF, Hong RT, Weng MJ, Yu GF, Kao CH. Comparison of multifidus muscle atrophy after posterior lumbar interbody fusion with conventional and cortical bone trajectory. Clin Neurol Neurosurg 2016; 145: 41-45
• 14 Chen YR, Deb S, Pham L, Singh H. Minimally Invasive Lumbar Pedicle Screw Fixation Using Cortical Bone Trajectory - A Prospective Cohort Study on Postoperative Pain Outcomes. Cureus 2016; 8 (07) e714-e726
• 15 Hu JN, Yang XF, Li CM, Li XX, Ding YZ. Comparison of cortical bone trajectory versus pedicle screw techniques in lumbar fusion surgery: A meta-analysis. Medicine (Baltimore) 2019; 98 (33) e16751-e16758
• 16 Sakaura H, Miwa T, Yamashita T, Kuroda Y, Ohwada T. Cortical bone trajectory screw fixation versus traditional pedicle screw fixation for 2-level posterior lumbar interbody fusion: comparison of surgical outcomes for 2-level degenerative lumbar spondylolisthesis. J Neurosurg Spine 2018; 28 (01) 57-62
• 17 Santoni BG, Hynes RA, McGilvray KC. et al. Cortical bone trajectory for lumbar pedicle screws. Spine J 2009; 9 (05) 366-373
• 18 Dayani F, Chen YR, Johnson E. et al. Minimally invasive lumbar pedicle screw fixation using cortical bone trajectory - Screw accuracy, complications, and learning curve in 100 screw placements. J Clin Neurosci 2019; 61: 106-111
• 19 Patel SS, Cheng WK, Danisa OA. Early complications after instrumentation of the lumbar spine using cortical bone trajectory technique. J Clin Neurosci 2016; 24: 63-67