Baptist Health South Florida Scholarly Commons @ Baptist Health South Florida All Publications 10-2017 Cortical Screws as an Alternative for Pedicle Screw Fixation for Unstable Degenerative Lumbar Spondylolisthesis: Technical note and Initial Results Daniel Segui Baptist Hospital of Miami, DanielSe@baptisthealth.net Sergio Gonzalez-Arias Baptist Hospital of Miami; Baptist Neuroscience Center, sergioga@baptisthealth.net Follow this and additional works at: https://scholarlycommons.baptisthealth.net/se-all-publications Citation Segui, Daniel and Gonzalez-Arias, Sergio, "Cortical Screws as an Alternative for Pedicle Screw Fixation for Unstable Degenerative Lumbar Spondylolisthesis: Technical note and Initial Results" (2017). All Publications. 2875. https://scholarlycommons.baptisthealth.net/se-all-publications/2875 This Conference Poster -- Open Access is brought to you for free and open access by Scholarly Commons @ Baptist Health South Florida. It has been accepted for inclusion in All Publications by an authorized administrator of Scholarly Commons @ Baptist Health South Florida. For more information, please contact Carrief@baptisthealth.net.
Cortical Screws as an Alternative for Pedicle Screw Fixation for Unstable Degenerative Lumbar Spondylolisthesis: Technical Note and Initial Results Reinier Alvarez BS; Nicole A. Colwell, MD; Zachary Aberman, MD; Angel Gabriel Chinea, MD; Carma Goldstein, MD; Alexander Braley, MD; Daniel Segui, MD; Sergio M. Gonzalez-Arias MD, PhD, FAANS, FACS Neuroscience Center, Baptist Health South Florida, Miami FL, USA Department of Neuroscience, Florida International University Herbert Wertheim College of Medicine, Miami FL, USA Introduction The implementation of cortical screws (CS) for posterior lumbar fusion offers a less invasive alternative that permits less soft tissue dissection compared to traditional lateral pedicle screw (PS) placement. CS provides greater cortical bone purchase within the pedicle due to the infero-medial to supero-lateral screw trajectory. Within, we present the technical notes and initial results of CS posterior lumbar fixation at our institution. Learning Objectives Image 2. Cortical Screws Provide Reduced Tissue Dissection and Smaller Incisions. Figure 1. (A) Spondylolisthesis Grade for Included Cases. (B) Fusion Levels for included Cases. Figure 2. Pre-Operative and Post-Operative ODI for 48 Cases. Results Methods Retrospective case series of 150 patients operated on by a single neurosurgeon from 2011-2016. Patients that underwent CS posterior lumbar fusion at 1 or 2 levels were included regardless of age or sex. Fifteen cases were excluded due to involving more than 2 levels, non-degenerative pathology, or revisions. Oswestry disability index (ODI) was recorded pre-operatively and at 3 months post-operatively. Radiographic evidence of motion was evaluated post-operatively at 3 month and 12 month follow-up visits. Retrospective IRB-approved initial chart review revealed that the CS approach provided a mean intraoperative time of 270.62 minutes, mean blood loss of 146.78 ml, and a mean inpatient length of stay for 2.77 days. Initial results for 48 patients revealed a statistically significant (p<0.0001) decrease between pre-operative and postoperative ODI at 3 month followup. Combined intra-operative neuronavigation and real time electrophysiologic screw monitoring in all patients (n=135) optimized lack of pedicular breach, as well as complications related to screw misplacement. References Table 2. Endpoints for Included Cases; Lumbar Fixation Evidenced by Motion on Post-Op Images for 122 Cases. Conclusions Our initial results support CS as a reasonable alternative to traditional PS trajectory for posterior lumbar fusion. Combined neuronavigation and electrophysiologic screw monitoring during CS placement can facilitate a less invasive approach that minimizes both the risk of injury to the posterior neural elements and the risk of pedicle breach. A decrease in length of stay and blood loss as well as comparable biomechanical properties to PS fixation, consistent with various reports in the literature support this approach. This technique provides an additional tool to the neurosurgeons armamentarium. Acknowledgements Image 1. Grade 1 Spondylolisthesis at L4-L5 with Bilateral CS Fixation; Pre-Op and Post-Op Images Showing InferoMedial to Supero-Lateral Trajectory. Table 1. Patient Demographics Appreciate the unique features and benefits of CS posterior lumbar fixation compared to traditional lateral PS trajectory. Discuss the technical nuances of CS posterior lumbar fusion. Understand the role of intraoperative neuronavigation and continuous electrophysiologic pedicle screw monitoring in preventing surgical morbidity. Table 3. Neuronavigation and Real-Time Neurophysiological Monitoring of CS for Included Cases. Amy K. Starosciak, Neuroscience Center Baptist Health South Florida; Anita McKay, Neuroscience Center Baptist Health South Florida; Kunal Patel, Neuroscience Center Baptist Health South Florida. Matsukawa K, Yato Y, Imabayashi H, Hosogane N, Asazuma T, et al. Biomechanical evaluation of the fixation strength of lumbar pedicle screws using cortical bone trajectory: a finite element study. J Neurosurg Spine. 2015 Oct;23(4):471-8. Lee GW, Son JH, Ahn MW, Kim HJ, Yeom JS. The comparison of pedicle screw and cortical screw in posterior lumbar interbody fusion: a prospective randomized noninferiority trial. Spine J. 2015 Jul 1;15(7):1519-26. Santoni BG, Hynes RA, McGilvray KC, Rodriguez-Canessa G, Lyons AS, et al. Cortical bone trajectory for lumbar pedicle screws. Spine J. 2009 May;9(5):366-73.
Image 1. Grade 1 Spondylolisthesis at L4-L5 with Bilateral CS Fixation; Pre-Op and Post-Op Images Showing Infero-Medial to Supero-Lateral Trajectory.
Image 2. Cortical Screws Provide Reduced Tissue Dissection and Smaller Incisions.
Table 1. Patient Demographics
Figure 1. (A) Spondylolisthesis Grade for Included Cases. (B) Fusion Levels for included Cases.
Table 2. Endpoints for Included Cases; Lumbar Fixation Evidenced by Motion on Post-Op Images for 122 Cases.
Table 3. Neuronavigation and Real-Time Neurophysiological Monitoring of CS for Included Cases.
Figure 2. Pre-Operative and Post-Operative ODI for 48 Cases.