Postoperative C5 Palsy after Anterior or Posterior Decompression for Degenerative Cervical Myelopathy: A Subgroup Analysis of the Multicenter, Prospective, Randomized, Phase III, CSM-Protect Clinical Trial.

STUDY DESIGN: Retrospective cohort study of prospectively accrued data. OBJECTIVE: To evaluate a large, prospective, multicentre dataset of surgically-treated DCM cases on the contemporary risk of C5 palsy with surgical approach. SUMMARY OF BACKGROUND DATA: The influence of surgical technique on postoperative C5 palsy after decompression for degenerative cervical myelopathy (DCM) is intensely debated. Comprehensive analyses are needed using contemporary data and accounting for covariates. METHODS: Patients with moderate to severe DCM were prospectively enrolled in the multicenter, randomized CSM-Protect clinical trial and underwent either anterior or posterior decompression between Jan 31, 2012, to May 16, 2017. The primary outcome was the incidence of postoperative C5 palsy, defined as onset of muscle weakness by at least one grade in manual muscle test at the C5 myotome with slight or absent sensory disruption after cervical surgery. Two comparative cohorts were made based on anterior or posterior surgical approach. Multivariate hierarchical mixed-effects logistic regression was used to estimate odds ratios (OR) with 95% confidence intervals (CI) for C5 palsy. RESULTS: A total of 283 patients were included, and 53.4% underwent posterior decompression. The total incidence of postoperative C5 palsy was 7.4% and was significantly higher in patients that underwent posterior decompression compared to anterior decompression (11.26% vs. 3.03%, P=0.008). After multivariable regression, posterior approach was independently associated with greater than four times the likelihood of postoperative C5 palsy (P=0.017). Rates of C5 palsy recovery were comparable between the two surgical approaches. CONCLUSION: The odds of postoperative C5 palsy are significantly higher after posterior decompression compared to anterior decompression for DCM. This may influence surgical decision-making when there is equipoise in deciding between anterior and posterior treatment options for DCM. LEVEL OF EVIDENCE: Therapeutic Level II.

The Impact of Interhospital Transfer on the Extent of Neurological Recovery in Acute Traumatic Spinal Cord Injury: Analysis of a Prospective Multicenter Data Set in 970 Cases.

BACKGROUND AND OBJECTIVES: Interhospital transfer from community hospitals to centers specialized in managing traumatically injured individuals can strain patients, healthcare systems, and delay appropriate care. The purpose was to compare long-term neurological outcomes in transferred or directly admitted patients with traumatic spinal cord injury (SCI). METHODS: An ambispective cohort study was conducted using prospectively collected data (between 2005 and 2018) from 11 specialized level 1 trauma centers across the United States and Canada. All patients who underwent surgical management for SCI were included and placed into 2 comparison cohorts: (1) direct admission and (2) transfer from intermediate hospital. Outcomes were change in American Spinal Injury Association Impairment Scale grade and its components: upper-extremity motor, lower-extremity motor, pinprick, and light touch scores from baseline (assessed ≤72 hours after injury) to follow-up (12-52 weeks). Nearest-neighbor 1:1 propensity score matching between the transferred and directly admitted cohorts was performed. Paired analysis using McNemar's test and paired Student's t -test was used to determine the extent of the difference in neurological outcomes. RESULTS: Nine hundred seventy patients (55.5% male, 55.2 ± 18.9 years) with traumatic SCI were directly admitted to a specialized trauma center (N = 474, 48.9%) or transferred from an intermediate hospital (N = 496, 51.1%). After propensity score matching, 283 pairs were matched. Compared with a matched cohort of transferred patients, American Spinal Injury Association Impairment Scale grade improved more in directly admitted patients (56.2% vs 46.3%, P = .024), as did upper-extremity motor score (13.7 ± 12.8 vs 10.4 ± 11.5, P = .018) and light touch score (22.0 ± 29.7 vs 16.9 ± 26.6, P = .034). CONCLUSION: Patients with SCI directly admitted to specialized trauma centers have greater neurological recovery compared with patients transferred from an intermediate hospital. Feasibility of direct admission to a center specialized in the management of acute SCI through implementation of a standardized code program must be further investigated. LEVEL OF EVIDENCE: Therapeutic level II.

Automated grading of anatomical objective structured practical examinations using decision trees: An artificial intelligence approach.

An Objective Structured Practical Examination (OSPE) is an effective and robust, but resource-intensive, means of evaluating anatomical knowledge. Since most OSPEs employ short answer or fill-in-the-blank style questions, the format requires many people familiar with the content to mark the examinations. However, the increasing prevalence of online delivery for anatomy and physiology courses could result in students losing the OSPE practice that they would receive in face-to-face learning sessions. The purpose of this study was to test the accuracy of Decision Trees (DTs) in marking OSPE questions as a first step to creating an intelligent, online OSPE tutoring system. The study used the results of the winter 2020 semester final OSPE from McMaster University's anatomy and physiology course in the Faculty of Health Sciences (HTHSCI 2FF3/2LL3/1D06) as the data set. Ninety percent of the data set was used in a 10-fold validation algorithm to train a DT for each of the 54 questions. Each DT was comprised of unique words that appeared in correct, student-written answers. The remaining 10% of the data set was marked by the generated DTs. When the answers marked by the DT were compared to the answers marked by staff and faculty, the DT achieved an average accuracy of 94.49% across all 54 questions. This suggests that machine learning algorithms such as DTs are a highly effective option for OSPE grading and are suitable for the development of an intelligent, online OSPE tutoring system.

Impact of Mechanism of Injury on Long-term Neurological Outcomes of Cervical Sensorimotor Complete Acute Traumatic Spinal Cord Injury.

OBJECTIVE: Mechanism of injury is a largely understudied descriptor of acute traumatic spinal cord injury (tSCI). This study sought to compare the impact of high-energy and low-energy mechanisms of injury in neurological outcomes of cervical sensorimotor complete tSCI. METHODS: Patients with tSCI were identified in 4 prospective, multicenter clinical trials and registries. American Spinal Injury Association Impairment Scale (AIS) grade was assessed ≤ 72 hours postinjury and followed up between 12 to 52 weeks. Patients were included if they had a cervical and sensorimotor complete (AIS-A) injury at baseline. Study outcomes were change in AIS grade and lower extremity motor, upper extremity motor, and total motor scores. Propensity score matching between high-energy mechanisms of injury (HEMI; e.g. , motor vehicle collisions) and low-energy mechanisms of injury (LEMI; e.g. , falls) groups was performed. Adjusted groups were compared with paired t-tests and McNemar test. RESULTS: Of 667 patients eligible for inclusion, 523 experienced HEMI (78.4%). HEMI patients were younger, had lower body mass index, more associated fractures or dislocations, and lower baseline lower extremity motor scores. After propensity score matching of these baseline variables, 118 pairs were matched. HEMI patients had a significantly worse motor recovery from baseline to follow-up based on their diminished change in upper extremity motor scores and total motor scores. CONCLUSION: Cervical sensorimotor complete tSCIs from HEMI were associated with significantly lower motor recovery compared to LEMI patients. Our findings suggest that mechanism of injury should be considered in modelling prognosis and in understanding the heterogeneity of outcomes after acute tSCI.

Virtual Reality Bell-Ringer: The Development and Testing of a Stereoscopic Application for Human Gross Anatomy.

As post-secondary education migrates online, developing and evaluating new avenues for assessment in anatomy is paramount. Three-dimensional (3D) visualization technology is one area with the potential to augment or even replace resource-intensive cadaver use in anatomical education. This manuscript details the development of a smartphone application, entitled "Virtual Reality Bell-Ringer (VRBR)," capable of displaying monoscopic two-dimensional (2D) or stereoscopic 3D images with the use of an inexpensive cardboard headset for use in spot examinations. Cadaveric image use, creation, and pinning processes are explained, and the source code is provided. To validate this tool, this paper compares traditional laboratory-based spot examination assessment stations against those administered using the VRBR application to test anatomical knowledge. Participants (undergraduate, n = 38; graduate, n = 13) completed three spot examinations specific to their level of study, one in each of the modalities (2D, 3D, laboratory) as well as a mental rotation test (MRT), Stereo Fly stereotest, and cybersickness survey. Repeated measures ANCOVA suggested participants performed significantly better on laboratory and 3D stations compared to 2D stations. Moderate to severe cybersickness symptoms were reported by 63% of participants in at least one category while using the VRBR application. Highest reported symptoms included: eye strain, general discomfort, difficulty focusing, and difficulty concentrating. Overall, the VRBR application is a promising tool for its portability, affordability, and accessibility. Due to reported cybersickness and other technical limitations, the use of VRBR as an alternative to cadaveric specimens presents several challenges when testing anatomy knowledge that must be addressed before widespread adoption.

Randomized Controlled Trials in Functional Neurosurgery-Association of Device Approval Status and Trial Quality.

INTRODUCTION: Randomized controlled trials (RCTs) have been critical in evaluating the safety and efficacy of functional neurosurgery interventions. Given this, we sought to systematically assess the quality of functional neurosurgery RCTs. METHODS: We used a database of neurosurgical RCTs (trials published from 1961 to 2016) to identify studies of functional neurosurgical procedures (N = 48). We extracted data on the design and quality of these RCTs and quantified the quality of trials using Jadad scores. We categorized RCTs based on the device approval status at the time of the trial and tested the association of device approval status with trial design and quality parameters. RESULTS: Of the 48 analyzed functional neurosurgery RCTs, the median trial size was 34.5 patients with a median age of 51. The most common indications were Parkinson's disease (N = 20), epilepsy (N = 10), obsessive-compulsive disorder (N = 4), and pain (N = 4). Most trials reported inclusion and exclusion criteria (95.8%), sample size per arm (97.9%), and baseline characteristics of the patients being studied (97.9%). However, reporting of allocation concealment (29.2%), randomization mode (66.7%), and power calculations (54.2%) were markedly less common. We observed that trial quality has improved over time (Spearman r, 0.49). We observed that trials studying devices with humanitarian device exemption (HDE) and experimental indications (EI) tended to be of higher quality than trials of FDA-approved devices (p = 0.011). A key distinguishing quality characteristic was the proportion of HDE and EI trials that were double-blinded, compared to trials of FDA-approved devices (HDE, 83.3%; EI, 69.2%; FDA-approved, 35.3%). Although more than one-third of functional neurosurgery RCTs reported funding from industry, no significant association was identified between funding source and trial quality or outcome. CONCLUSION: The quality of RCTs in functional neurosurgery has improved over time but reporting of specific metrics such as power calculations and allocation concealment requires further improvement. Device approval status but not funding source was associated with trial quality.