Development of a Predictive Model for Persistent Instability Following Conservative Management of Type II Odontoid Fractures.

BACKGROUND: Odontoid fractures are common cervical spine fractures; however, significant controversy exists regarding their treatment. Risk factors for failure of conservative therapy have been identified, although no predictive risk score has been developed to aid in decision-making. METHODS: A retrospective review was conducted of all patients evaluated at a level 1 trauma center. Patients identified with type II odontoid fractures as classified by the D'Alonzo Classification system who were treated with external orthosis were included in analysis. Patients were considered to have failed conservative therapy if they were offered surgical intervention. A machine learning method (Risk-SLIM) was then utilized to create a risk stratification score based on risk factors to identify patients at high risk for requiring surgical intervention due to persistent instability. RESULTS: A total of 138 patients were identified as presenting with type II odontoid fractures that were treated conservatively; 38 patients were offered surgery for persistent instability. The Odontoid Fracture Predictive Model (OFPM) was created using a machine learning algorithm with a 5-fold cross validation area under the curve of 0.7389 (95% CI: 0.671 to 0.808). Predictive factors were found to include fracture displacement, displacement greater than 5 mm, comminution at the fracture base, and history of smoking. The probability of persistent instability was <5% with a score of 0 and 88% with a score of 5. CONCLUSIONS: The OFPM model is a unique, quick, and accurate tool to assist in clinical decision-making in patients with type II odontoid fractures. External validation is necessary to evaluate the validity of these findings.

Applications of navigation in full-endoscopic spine surgery.

PURPOSE: Advancement in all surgery continues to progress towards more minimally invasive surgical (MIS) approaches. One of the platform technologies which has helped drive this trend within spine surgery is the development of endoscopy; however, the limited anatomic view experienced when performing endoscopic spine surgery requires a significant learning curve. The use of intraoperative navigation has been adapted for endoscopic spine surgery, as this provides computer-reconstructed visual data presented in three dimensions, which can increase feasibility of this technique to more surgeons. METHODS: This paper will describe the principles, technical considerations, and applications of stereotactic navigation-guided endoscopic spine surgery. RESULTS: Full-endoscopic spine surgery has advanced in recent years such that it can be utilized in both decompressive and fusion surgeries. One of the major pitfalls to any minimally invasive surgery (including endoscopic) is that the limited surgical view can often complicate the surgery or confuse the surgeon, leading to longer operative times, higher risks, among others. This is the real utility to using navigation in conjunction with the endoscope-when registered correctly and utilized appropriately, navigated endoscopic spine surgery can take some of the guesswork out of the minimally invasive approach. CONCLUSIONS: Using navigation with endoscopy in spine surgery can potentially expand this technique to surgeons who have yet to master endoscopy as the assistance provided by the navigation can alleviate some of the complexities with anatomic understanding and surgical planning.

Safety and Efficacy of Riluzole in Acute Spinal Cord Injury Study (RISCIS): A Multi-Center, Randomized, Placebo-Controlled, Double-Blinded Trial.

Riluzole is a sodium-glutamate antagonist that attenuates neurodegeneration in amyotrophic lateral sclerosis (ALS). It has shown favorable results in promoting recovery in pre-clinical models of traumatic spinal cord injury (tSCI) and in early phase clinical trials. This study aimed to evaluate the efficacy and safety of riluzole in acute cervical tSCI. An international, multi-center, prospective, randomized, double-blinded, placebo-controlled, adaptive, Phase III trial (NCT01597518) was undertaken. Patients with American Spinal Injury Association Impairment Scale (AIS) A-C, cervical (C4-C8) tSCI, and <12 h from injury were randomized to receive either riluzole, at an oral dose of 100 mg twice per day (BID) for the first 24 h followed by 50 mg BID for the following 13 days, or placebo. The primary efficacy end-point was change in Upper Extremity Motor (UEM) scores at 180 days. The primary efficacy analyses were conducted on an intention to treat (ITT) and completed cases (CC) basis. The study was powered at a planned enrolment of 351 patients. The trial began in October 2013 and was halted by the sponsor on May 2020 (and terminated in April 2021) in the face of the global COVID-19 pandemic. One hundred ninety-three patients (54.9% of the pre-planned enrolment) were randomized with a follow-up rate of 82.7% at 180 days. At 180 days, in the CC population the riluzole-treated patients compared with placebo had a mean gain of 1.76 UEM scores (95% confidence interval: -2.54-6.06) and 2.86 total motor scores (CI: -6.79-12.52). No drug-related serious adverse events were associated with the use of riluzole. Additional pre-planned sensitivity analyses revealed that in the AIS C population, riluzole was associated with significant improvement in total motor scores (estimate: standard error [SE] 8.0; CI 1.5-14.4) and upper extremity motor scores (SE 13.8; CI 3.1-24.5) at 6 months. AIS B patients had higher reported independence, measured by the Spinal Cord Independence Measure score (45.3 vs. 27.3; d: 18.0 CI: -1.7-38.0) and change in mental health scores, measured by the Short Form 36 mental health domain (2.01 vs. -11.58; d: 13.2 CI: 1.2-24.8) at 180 days. AIS A patients who received riluzole had a higher average gain in neurological levels at 6 months compared with placebo (mean 0.50 levels gained vs. 0.12 in placebo; d: 0.38, CI: -0.2-0.9). The primary analysis did not achieve the predetermined end-point of efficacy for riluzole, likely related to insufficient power. However, on pre-planned secondary analyses, all subgroups of cervical SCI subjects (AIS grades A, B and C) treated with riluzole showed significant gains in functional recovery. The results of this trial may warrant further investigation to extend these findings. Moreover, guideline development groups may wish to assess the possible clinical relevance of the secondary outcome analyses, in light of the fact that SCI is an uncommon orphan disorder without an accepted neuroprotective treatment.

Socioeconomic Disparities in Outcomes Following Conservative Treatment of Spinal Epidural Abscesses.

BACKGROUND: Primary spinal epidural abscess (SEA) is a rare but serious pathology that may result in severe neurologic injury. While certain literature has identified medical risk factors for failure of conservative therapy, no current evidence has been published regarding socioeconomic risk factors associated with failure of medical therapy. METHODS: A retrospective review was conducted of patients presenting with SEA from primary spinal infections. Patients presenting with magnetic resonance imaging evidence of SEA treated conservatively in the absence of neurologic deficits were included. Baseline clinical and socioeconomic characteristics were collected. Failure of medical management was defined as requiring surgical intervention despite maximal medical therapy due to the development of neurologic deficits or clinically significant deformity. RESULTS: A total of 150 patients were identified as presenting with magnetic resonance imaging evidence of SEAs without evidence of neurologic deficit. Of these patients, 42 required surgical intervention compared with 108 whose infection was successfully treated with medical therapy alone. Estimated average annual income was $64,746 vs $62,615 in those who successfully cleared their infection with medical management without requiring surgery, which was not statistically significant (P = 0.5). Insured patients were 5 times more likely to be successfully treated with antibiotics alone compared with uninsured patients (OR = 5.83, P = 0.008). Payer type, employment status, and incarceration status were not associated with failure of conservative therapy. CONCLUSIONS: In the treatment of primary SEA, absence of medical insurance is associated with failure of medical management. Payer status, employment status, average salary, and incarceration are not significant risk factors for failure of conservative management.

Delays in Presentation After Traumatic Spinal Cord Injury-A Systematic Review.

BACKGROUND: Prompt surgical decompression after traumatic spinal cord injury (TSCI) may be associated with improved sensorimotor outcomes. Delays in presentation may prevent timely decompression after TSCI. OBJECTIVE: To systematically review existing studies investigating delays in presentation after TSCI in low- and middle-income countries (LMICs) and high-income countries (HICs). METHODS: A systematic review was conducted and studies featuring quantitative or qualitative data on prehospital delays in TSCI presentation were included. Studies lacking quantitative or qualitative data on prehospital delays in TSCI presentation, case reports or series with <5 patients, review articles, or animal studies were excluded from our analysis. RESULTS: After exclusion criteria were applied, 24 studies were retained, most of which were retrospective. Eleven studies were from LMICs and 13 were from HICs. Patients with TSCI in LMICs were younger than those in HICs, and most patients were male in both groups. A greater proportion of patients with TSCI in studies from LMICs presented >24 hours after injury (HIC average proportion, 12.0%; LMIC average proportion, 49.9%; P = 0.01). Financial barriers, lack of patient awareness and education, and prehospital transportation barriers were more often cited as reasons for delays in LMICs than in HICs, with prehospital transportation barriers cited as a reason for delay by every LMIC study included in this review. CONCLUSIONS: Disparities in prehospital infrastructure between HICs and LMICs subject more patients in LMICs to increased delays in presentation to care.

Transient internuclear ophthalmoplegia following anterior cervical discectomy and fusion.

Background: Internuclear ophthalmoplegia (INO), characterized by impaired horizontal eye movement, occurred following an anterior cervical discectomy/fusions (ACDF). Case Description: A 48-year-old female with recurrent C5-6 foraminal stenosis presented with right C6 radiculopathy. She underwent a C5-6 ACDF, but postoperatively, complained of diplopia. Her examination revealed left-eye INO. Notably, the brain magnetic resonance imaging showed no significant radiological findings. The patient's diplopia and INO resolved spontaneously on postoperative day 2 and never recurred. Conclusion: Ocular complications following anterior cervical spine procedures are rare. Here, a 48-year-old female developed left eye INO following an ACDF that spontaneously resolved on postoperative day 2.

Outcomes following conservative treatment of extension fractures in the setting of diffuse idiopathic skeletal hyperostosis: is external orthosis alone a reasonable option?

OBJECTIVE: Extension fractures in the setting of diffuse idiopathic skeletal hyperostosis (DISH) represent highly unstable injuries. As a result, these fractures are most frequently treated with immediate surgical fixation to limit any potential risk of associated neurological injury. Although this represents the standard of care, patients with significant comorbidities, advanced age, or medical instability may not be surgical candidates. In this paper, the authors evaluated a series of patients with extension DISH fractures who were treated with orthosis alone and evaluated their outcomes. METHODS: A retrospective review from 2015 to 2022 was conducted at a large level 1 trauma center. Patients with extension-type DISH fractures without neurological deficits were identified. All patients were treated conservatively with orthosis alone. Baseline patient characteristics and adverse outcomes are reported. RESULTS: Twenty-seven patients were identified as presenting with extension fractures associated with DISH without neurological deficit. Of these, 22 patients had complete follow-up on final chart review. Of these 22 patients, 21 (95.5%) were treated successfully with external orthosis. One patient (4.5%) who was noncompliant with the brace had an acute spinal cord injury 1 month after presentation, requiring immediate surgical fixation and decompression. No other complications, including skin breakdown or pressure ulcers related to bracing, were reported. CONCLUSIONS: Treatment of extension-type DISH fractures may be a reasonable option for patients who are not candidates for safe surgical intervention; however, a risk of neurological injury secondary to delayed instability remains, particularly if patients are noncompliant with the bracing regimen. This risk should be balanced against the high complication rate and potential mortality associated with surgical intervention in this patient population.

Development and Validation of a Predictive Model for Failure of Medical Management in Spinal Epidural Abscesses.

BACKGROUND: The optimal management of spinal epidural abscesses (SEA) secondary to primary spinal infections has demonstrated large variability in the literature. Although some literature suggests a high rate of neurological deterioration, others suggest failure of medical management is uncommon. OBJECTIVE: To develop a predictive model to evaluate the likelihood of failure of medical therapy in the setting of SEA. METHODS: A retrospective review was conducted of all patients presenting with SEA from primary spinal infections. Patients presenting with MRI evidence of SEA without neurological deficits were included. Failure of medical management was defined as requiring surgical intervention over 72 hours after the initiation of antibiotics. A machine learning method (Risk-Calibrated Supersparse Linear Integer Model) was used to create a risk stratification score to identify patients at high risk for requiring surgical intervention. RESULTS: In total, 159 patients were identified as presenting with MRI findings of SEA without evidence of neurological deficit. Of these patients, 50 required delayed surgery compared with 109 whose infection were successfully treated with surgical intervention. The Spinal Epidural Abscess Predictive Score was created using a machine learning model with an area under the curve of 0.8043 with calibration error of 14.7%. Factors included active malignancy, spondylodiscitis, organism identification, blood cultures, and sex. The probability of failure of medical management ranged from <5% for a score of 2 or less and >95% for a score of 7 or more. CONCLUSION: The Spinal Epidural Abscess Predictive Score model is a quick and accurate tool to assist in clinical decision-making in SEA.

External Review and Validation of a Spinal Epidural Abscess Predictive Score for Clinical Failure.

BACKGROUND: Spinal epidural abscess (SEA) is a rare but serious pathology that may result in delayed neurologic injury despite treatment with antibiotic therapy or surgery. Given this, the development of predictive scores for risk stratification has value in clinical decision making; however, external validation is necessary to understand their generalizability and reliability. METHODS: A retrospective review was conducted of all patients presenting with SEA at a single institution. Patients were reviewed and graded according to the proposed SEA predictive score by Baum et al. Clinical failure was defined as documented laboratory or radiographic progression requiring surgical intervention, increased deformity requiring surgical intervention, or repeat surgical intervention if prior surgical intervention was undertaken as the initial treatment strategy. Brier score and receiver operating characteristic were used to calculate reliability. RESULTS: There were 224 patients presenting with primary spinal infections with associated SEA. Of these, 209 patients had no history of intravenous drug abuse. Clinical failure was demonstrated in 52 of 209 patients (24.9%). Antibiotic treatment alone compared with antibiotic therapy and surgical treatment on initial presentation was found to have a significantly greater chance of clinical failure (odds ratio = 3.0930, P = 0.01). The proposed epidural abscess prediction score did not correlate with clinical outcomes with a Brier score of 0.229 and receiver operating characteristic area under the curve of 0.5944. CONCLUSIONS: The proposed risk stratification scale for patients was not correlated with risk of clinical failure. Additionally, patients treated with antibiotics and surgical intervention on initial presentation had a significantly lower clinical failure rate.

Primary spinal infections: A retrospective review of instrumentation use and graft selection.

Background: The use of instrumentation in the setting of primary spinal infections is controversial. While the instrumentation is often required in the presence of progressive deformity due to spinal osteomyelitis (SO), discitis (SD), or spinal epidural abscesses (SEA), many surgeons are concerned about instrumentation increasing the risk of infection recurrence and/or persistence warranting reoperation. Methods: We retrospectively reviewed the need for reoperations for persistent infections in 119 patients who presented with primary spinal infections. They were treated with decompressions with/without non-instrumented fusion (70 patients) versus decompressions with instrumented fusions (49 patients). Results: The use of primary spinal instrumentation in the presence of infection (SO/SD/SEA) did not increase the requirement for repeated surgery due to recurrent/residual infection when compared to those undergoing decompressions with/without non-instrumented fusions. Of 49 patients who initially required instrumentation, 6 (12.5%) required reoperations for recurrent or residual infection. For the 71 undergoing index decompressions for infection with/without non-instrumented fusion, 9 (12.7%), or nearly an identical percentage, required reoperations for recurrent/residual infection (P = 0.93). Conclusion: The use of instrumentation in the treatment of primary spinal infections in a small sample of just 49 patients did not increase the risk for persistent infection warranting reoperations versus 70 patients undergoing initial decompressions with/without non-instrumented fusions.

Early Decompression and Short Transport Time After Traumatic Spinal Cord Injury are Associated with Higher American Spinal Injury Association Impairment Scale Conversion.

STUDY DEIGN: Retrospective cohort study. OBJECTIVES: This retrospective cohort study aims to determine the association of early decompressive surgery and the impact of transport time on the neurological outcomes of traumatic spinal cord injury (tSCI) patients. SUMMARY OF BACKGROUND DATA: tSCI is a catastrophic event that may result in permanent disability or loss of function. To date, there remains significant controversy over the optimal time for surgical decompression in tSCI patients. The aim of this study is to evaluate the neurological outcomes of tSCI patients undergoing early versus late surgical decompression and the impact of transport time on neurological outcomes. METHODS: Data from 84 patients with tSCI requiring surgical decompression was collected. Regression analysis was used to establish time to decompression classification cutoffs. Patients were classified into the following subgroups: 0 to 12 or >12 hours as a factor of the total or admitting hospital time to decompression. The change in American Spinal Injury Association Impairment (AIS) Grade from admission to discharge was determined. Additionally, the effect of transport time on conversion of AIS grade was assessed as patients were grouped into transport times of <6 or >6 hours. RESULT: Among the time to decompression subgroups there were no significant differences (P > 0.05) in confounding factors such as age, injury severity, and AIS grade. Patients who received decompression within 0 to 12 hours were associated with significantly (P < 0.0001) higher average improvements in ASIA grade (0.76). Patient transport times <6 hours were associated with significantly (P = 0.004) higher conversion of AIS grade to less impaired states. CONCLUSION: The present study suggests an association of decompression within 12 hours and short transport times (<6 hours) with significant improvements in neurological outcomes.Level of Evidence: 4.

Development and Validation of a Low-Cost Endoscopic Spine Surgery Simulator.

Background Minimally invasive endoscopic techniques in spine surgery continue to gain in popularity. Unfortunately, there is a long learning period for novice endoscope users to acquire basic skills, and complex training simulators are frequently cost-prohibitive. This paper describes the development and validation of a low-cost endoscopic spine training simulator. Methodology A low-cost endoscopic spine training model was created utilizing a budget of less than 65 USD. Afterward, a training curriculum consisting of five tasks was designed to mimic standard techniques frequently utilized in endoscopic spine surgery. This curriculum was tested on a cohort of surgical trainees. The initial time to completion as well as errors made during the tasks and repeat trials were recorded. A composite score was generated to quantify the overall scores which included both time and errors in each task. Results In total, 11 students and surgical residents completed the curriculum. The first attempt required an average of 622 seconds for the completion of the curriculum compared to 283 seconds in the second trial (p < 0.001; SD = 36.75). In regards to trials in which errors were counted, fewer errors occurred during the second attempt (2.55 vs. 1.53); however, this difference was not statistically significant (p > 0.05). In regards to the composite score, the composite score of the intern group demonstrated an average improvement of 0.345 compared to an average improvement of 0.47 in the resident group. Conclusions Our study demonstrates the feasibility of a low-cost endoscopic spine trainer as well as its efficacy in improving basic endoscopic skills in trainees.

Association of helmet use with traumatic brain and cervical spine injuries following bicycle crashes.

Background: The use of bicycle helmets in preventing traumatic brain injuries (TBI) is frequently cited but data remain inconclusive. Additionally, the effects of helmets on cervical spine injuries (CSI) are debated.Methods: We performed a retrospective review of all adult patients with bicycle crashes presenting to one level 1 trauma center in Wisconsin from 2010 to 2016. Patients were divided into two groups: helmeted and un-helmeted.Results: In total 287 patients were included; 149 un-helmeted (51.9%) and 138 helmeted (48.9%). Helmeted riders had radiographic evidence of traumatic brain injury in 20.3% of cases compared to 40.3% of un-helmeted (p < 0.001). On average, helmeted riders had a similar injury severity score of 7.80 (standard deviation (SD) = 7.18) compared with 8.25 (SD = 9.98) in the un-helmeted group (p = 0.68). CSI occurred in 16 (10.7%) un-helmeted patients compared with 15 (10.9%) helmeted patients (p = 0.707). Of the un-helmeted group, four patients (2.7%) were found to have a cervical spine fracture compared with 12 (8.7%) helmeted patients (p = 0.037).Conclusion: Helmet use demonstrated a statistically significant advantage in the prevention of traumatic brain injuries. No significant difference was found regarding the incidence of severity of cervical spine injuries. These results do not demonstrate any statistically significant benefit in the prevention of cervical spine injuries with helmet use. In contrast, helmet use was found to convey a significant protective advantage in the prevention of traumatic brain injuries compared to no helmets.

Posterior Endoscopic Cervical Foraminotomy.

Unilateral cervical nerve root compression causing radiculopathy, which does not improve with conservative measures, is safely and effectively treated with surgery. Both anterior and posterior approaches have been described. Overall results from either of these broad categories of approaches are equivalent. Posterior approaches target the cervical root compression directly and allow decompression by widening the neural foramen and/or removing a lateral disc fragment. Following success of the open technique, variations of this technique were introduced to minimize approach-related complications.

Motorcycle helmets and cervical spine injuries: a 5-year experience at a Level 1 trauma center.

OBJECTIVE Motorcycle helmets have been shown to decrease the incidence and severity of traumatic brain injury due to motorcycle crashes. Despite this proven efficacy, some previous reports and speculation suggest that helmet use is associated with a higher likelihood of cervical spine injury (CSI). In this study, the authors examine 1061 cases of motorcycle crash victims who were treated during a 5-year period at a Level 1 trauma center to investigate the association of helmet use with the incidence and severity of CSI. The authors hypothesized that wearing a motorcycle helmet during a motorcycle crash is not associated with an increased risk of CSI and may provide some protective advantage to the wearer. METHODS The authors performed a retrospective review of all cases in which the patient had been involved in a motorcycle crash and was evaluated at a single Level 1 trauma center in Wisconsin between January 1, 2010, and January 1, 2015. Biometric, clinical, and imaging data were obtained from a trauma registry database. The patients were then divided into 2 distinct groups based on whether or not they were wearing helmets at the time of the accident. Baseline and functional characteristics were compared between the 2 groups. The Student t-test was used for continuous variables, and Pearson's chi-square analysis was used for categorical variables. RESULTS In total, 1061 patient charts were examined containing data on 738 unhelmeted (69.6%) and 323 helmeted (30.4%) motorcycle riders. On average, helmeted riders had a much lower Injury Severity Score (p < 0.001). Cervical spine injury occurred in 114 unhelmeted riders (15.4%) compared with only 24 helmeted riders (7.4%) (p < 0.001), with an adjusted odds ratio of 2.3 (95% CI 1.44-3.61, p = 0.0005). In the unhelmeted group, 10.8% of patients were found to have a cervical spine fracture compared with only 4.6% of patients in the helmeted group (p = 0.001). Additionally, ligamentous injury occurred more frequently in unhelmeted riders (1.9% vs 0.3%, p = 0.04). No difference was found in the occurrence of cervical strain, cord contusion, or nerve root injury (all p > 0.05). CONCLUSIONS The results of this study demonstrate a statistically significant lower likelihood of suffering a CSI among helmeted motorcyclists. Unhelmeted riders sustained a statistically significant higher number of vertebral fractures and ligamentous injuries. The study findings reported here confirm the authors' hypothesis that helmet use does not increase the risk of developing a cervical spine fracture and may provide some protective advantage.

The Development of Augmented Reality to Enhance Minimally Invasive Surgery.

Minimally invasive surgery (MIS) reduces unnecessary tissue damage to the patient but obscures the natural surgical interface that is provided by open surgical procedures. Multiple feedback mechanisms, mainly visual and tactile, are greatly reduced in MIS. Microscopes, endoscopes, and image-guided navigation traditionally provide enough visual information for successful minimally invasive procedures, although the limited feedback makes these procedures more difficult to learn. Research has been performed to develop alternative solutions that regain additional feedback. Augmented reality (AR), a more recent guidance innovation that overlays digital visual data physically, has begun to be implemented in various applications to improve the safety and efficacy of minimally invasive procedures. This review focuses on the recent implementation of augmented display and direct visual overlay and discusses how these innovations address common feedback concerns associated with minimally invasive surgeries.

Central Cord Syndrome.

Central cord syndrome is a common spinal cord injury. The purpose of this review article is to provide an overview of the anatomy, pathophysiology, prognosis, and management of this disorder.