Comparing Cortical Bone Trajectory and Traditional Pedicle Screws in Transforaminal Lumbar Interbody Fusion: A Retrospective Cohort Study of One-Year Outcomes.

INTRODUCTION: This is a retrospective study of consecutive patients undergoing transforaminal lumbar interbody fusion (TLIF) at a single institution. The objective of this study was to compare the long-term results associated with cortical bone trajectory (CBT) and traditional pedicle screw (TPS) via posterolateral approach in TLIF. METHODS: Consecutive patients treated from November 2014 to March 2019 were included in the CBT TLIF group, while consecutive patients treated from October 2010 to August 2017 were included in the TPS TLIF group. Inclusion criteria comprised single-level or two-level TLIF for degenerative spondylolisthesis with stenosis and at least one year of clinical and radiographic follow-up. Variables of interest included pertinent preoperative, perioperative, and postoperative data. Non-parametric evaluation was performed using the Wilcoxon test. Fisher's exact test was used to assess group differences for nominal data. RESULTS: Overall, 140 patients met the inclusion criteria; 69 patients had CBT instrumentation (mean follow-up 526 days) and 71 patients underwent instrumentation placement via TPS (mean follow-up 825 days). Examination of perioperative and postoperative outcomes demonstrate comparable results between the groups with perioperative complications, length of stay, discharge destination, surgical revision rate, and fusion rates all being similar between groups (p = 0.1; p = 0.53; p = 0.091; p = 0.61; p = 0.665, respectively). CONCLUSIONS: CBT in the setting of TLIF offer equivalent outcomes to TPS with TLIF at both short- and long-term intervals of care.

Opioid-Free Anesthesia for Craniotomy.

BACKGROUND: Perioperative opioids are problematic following craniotomy as they can impede neurological examination because of excessive sedation and mask surgical complications. Multimodal anesthetic techniques including nerve blocks have been used successfully to deliver opioid-free anesthesia in other surgical populations; however, no clinical data evaluating opioid-free anesthesia for craniotomy exists within the current body of literature. MATERIALS AND METHODS: Six prospectively identified patients underwent supratentorial craniotomy at Emory University Hospital using a multimodal opioid-free anesthetic (OFA) technique consisting of preoperative scalp block, dexmedetomidine and intravenous acetaminophen. These opioid-free patients were matched by age, sex, incision length, and incision location to 18 retrospectively identified control patients who underwent craniotomy using conventional, opioid-based anesthetic techniques. Postoperative opioid consumption and pain scores were compared and analyzed for noninferiority. RESULTS: Noninferiority of the OFA technique was demonstrated for opioid consumption at all measured intervals from postanesthesia care unit arrival to 24 hours postoperatively. Noninferiority was also demonstrated with respect to average postoperative pain scores from 0 to 12 hours, 0 to 24 hours, as well as length of postanesthesia care unit stay. Noninferiority was not shown for time to first rescue opioid postoperatively, pain scores for the 12 to 24 hours postoperative period, or time to emergence from anesthesia. CONCLUSIONS: This pilot study demonstrates the feasibility of an OFA technique for patients undergoing supratentorial craniotomy and suggests that larger prospective randomized controlled trials are indicated to examine the role of multimodal anesthetic techniques for craniotomy.

Acutely unstable cervical spine injury with normal CT scan findings: MRI detects ligamentous injury.

MRI can detect ligamentous injury not detectable with CT scan. The authors present a trauma patient with normal CT imaging despite dislocation on standing radiograph. MRI detected disruption of the C5-C6 posterior ligamentous complex that requires surgery.

Neural pathfinding on uni- and multidirectional photopolymerized micropatterns.

Overcoming signal resolution barriers of neural prostheses, such as the commercially available cochlear impant (CI) or the developing retinal implant, will likely require spatial control of regenerative neural elements. To rationally design materials that direct nerve growth, it is first necessary to determine pathfinding behavior of de novo neurite growth from prosthesis-relevant cells such as spiral ganglion neurons (SGNs) in the inner ear. Accordingly, in this work, repeating 90° turns were fabricated as multidirectional micropatterns to determine SGN neurite turning capability and pathfinding. Unidirectional micropatterns and unpatterned substrates are used as comparisons. Spiral ganglion Schwann cell alignment (SGSC) is also examined on each surface type. Micropatterns are fabricated using the spatial reaction control inherent to photopolymerization with photomasks that have either parallel line spacing gratings for unidirectional patterns or repeating 90° angle steps for multidirectional patterns. Feature depth is controlled by modulating UV exposure time by shuttering the light source at given time increments. Substrate topography is characterized by white light interferometry and scanning electron microscopy (SEM). Both pattern types exhibit features that are 25 µm in width and 7.4 ± 0.7 µm in depth. SGN neurites orient randomly on unpatterned photopolymer controls, align and consistently track unidirectional patterns, and are substantially influenced by, but do not consistently track, multidirectional turning cues. Neurite lengths are 20% shorter on multidirectional substrates compared to unidirectional patterns while neurite branching and microfeature crossing events are significantly higher. For both pattern types, the majority of the neurite length is located in depressed surface features. Developing methods to understand neural pathfinding and to guide de novo neurite growth to specific stimulatory elements will enable design of innovative biomaterials that improve functional outcomes of devices that interface with the nervous system.