Understanding Decision Making as It Influences Treatment in Thoracolumbar Burst Fractures Without Neurological Deficit: Conceptual Framework and Methodology.

STUDY DESIGN: This paper presents a description of a conceptual framework and methodology that is applicable to the manuscripts that comprise this focus issue. OBJECTIVES: Our goal is to present a conceptual framework which is relied upon to better understand the processes through which surgeons make therapeutic decisions around how to treat thoracolumbar burst fractures (TL) fractures. METHODS: We will describe the methodology used in the AO Spine TL A3/4 Study prospective observational study and how the radiographs collected for this study were utilized to study the relationships between various variables that factor into surgeon decision making. RESULTS: With 22 expert spine trauma surgeons analyzing the acute CT scans of 183 patients with TL fractures we were able to perform pairwise analyses, look at reliability and correlations between responses and develop frequency tables, and regression models to assess the relationships and interactions between variables. We also used machine learning to develop decision trees. CONCLUSIONS: This paper outlines the overall methodological elements that are common to the subsequent papers in this focus issue.

Using Equipoise to Determine the Radiographic Characteristics Leading to Agreement on Best Treatment for Thoracolumbar Burst Fractures Without Neurologic Deficits.

STUDY DESIGN: Retrospective analysis of prospectively collected data. OBJECTIVES: Our goal was to assess radiographic characteristics associated with agreement and disagreement in treatment recommendation in thoracolumbar (TL) burst fractures. METHODS: A panel of 22 AO Spine Knowledge Forum Trauma experts reviewed 183 cases and were asked to: (1) classify the fracture; (2) assess degree of certainty of PLC disruption; (3) assess degree of comminution; and (4) make a treatment recommendation. Equipoise threshold used was 77% (77:23 distribution of uncertainty or 17 vs 5 experts). Two groups were created: consensus vs equipoise. RESULTS: Of the 183 cases reviewed, the experts reached full consensus in only 8 cases (4.4%). Eighty-one cases (44.3%) were included in the agreement group and 102 cases (55.7%) in the equipoise group. A3/A4 fractures were more common in the equipoise group (92.0% vs 83.7%, P < .001). The agreement group had higher degree of certainty of PLC disruption [35.8% (SD 34.2) vs 27.6 (SD 27.3), P < .001] and more common use of the M1 modifier (44.3% vs 38.3%, P < .001). Overall, the degree of comminution was slightly higher in the equipoise group [47.8 (SD 20.5) vs 45.7 (SD 23.4), P < .001]. CONCLUSIONS: The agreement group had a higher degree of certainty of PLC injury and more common use of M1 modifier (more type B fractures). The equipoise group had more A3/A4 type fractures. Future studies are required to identify the role of comminution in decision making as degree of comminution was slightly higher in the equipoise group.

Predictive Algorithm for Surgery Recommendation in Thoracolumbar Burst Fractures Without Neurological Deficits.

STUDY DESIGN: Predictive algorithm via decision tree. OBJECTIVES: Artificial intelligence (AI) remain an emerging field and have not previously been used to guide therapeutic decision making in thoracolumbar burst fractures. Building such models may reduce the variability in treatment recommendations. The goal of this study was to build a mathematical prediction rule based upon radiographic variables to guide treatment decisions. METHODS: Twenty-two surgeons from the AO Knowledge Forum Trauma reviewed 183 cases from the Spine TL A3/A4 prospective study (classification, degree of certainty of posterior ligamentous complex (PLC) injury, use of M1 modifier, degree of comminution, treatment recommendation). Reviewers' regions were classified as Europe, North/South America and Asia. Classification and regression trees were used to create models that would predict the treatment recommendation based upon radiographic variables. We applied the decision tree model which accounts for the possibility of non-normal distributions of data. Cross-validation technique as used to validate the multivariable analyses. RESULTS: The accuracy of the model was excellent at 82.4%. Variables included in the algorithm were certainty of PLC injury (%), degree of comminution (%), the use of M1 modifier and geographical regions. The algorithm showed that if a patient has a certainty of PLC injury over 57.5%, then there is a 97.0% chance of receiving surgery. If certainty of PLC injury was low and comminution was above 37.5%, a patient had 74.2% chance of receiving surgery in Europe and Asia vs 22.7% chance in North/South America. Throughout the algorithm, the use of the M1 modifier increased the probability of receiving surgery by 21.4% on average. CONCLUSION: This study presents a predictive analytic algorithm to guide decision-making in the treatment of thoracolumbar burst fractures without neurological deficits. PLC injury assessment over 57.5% was highly predictive of receiving surgery (97.0%). A high degree of comminution resulted in a higher chance of receiving surgery in Europe or Asia vs North/South America. Future studies could include clinical and other variables to enhance predictive ability or use machine learning for outcomes prediction in thoracolumbar burst fractures.

The AO Spine Thoracolumbar Injury Classification System and Treatment Algorithm in Decision Making for Thoracolumbar Burst Fractures Without Neurologic Deficit.

STUDY DESIGN: Prospective Observational Study. OBJECTIVE: To determine the alignment of the AO Spine Thoracolumbar Injury Classification system and treatment algorithm with contemporary surgical decision making. METHODS: 183 cases of thoracolumbar burst fractures were reviewed by 22 AO Spine Knowledge Forum Trauma experts. These experienced clinicians classified the fracture morphology, integrity of the posterior ligamentous complex and degree of comminution. Management recommendations were collected. RESULTS: There was a statistically significant stepwise increase in rates of operative management with escalating category of injury (P < .001). An excellent correlation existed between recommended expert management and the actual treatment of each injury category: A0/A1/A2 (OR 1.09, 95% CI 0.70-1.69, P = .71), A3/4 (OR 1.62, 95% CI 0.98-2.66, P = .58) and B1/B2/C (1.00, 95% CI 0.87-1.14, P = .99). Thoracolumbar A4 fractures were more likely to be surgically stabilized than A3 fractures (68.2% vs 30.9%, P < .001). A modifier indicating indeterminate ligamentous injury increased the rate of operative management when comparing type B and C injuries to type A3/A4 injuries (OR 39.19, 95% CI 20.84-73.69, P < .01 vs OR 27.72, 95% CI 14.68-52.33, P < .01). CONCLUSIONS: The AO Spine Thoracolumbar Injury Classification system introduces fracture morphology in a rational and hierarchical manner of escalating severity. Thoracolumbar A4 complete burst fractures were more likely to be operatively managed than A3 fractures. Flexion-distraction type B injuries and translational type C injuries were much more likely to have surgery recommended than type A fractures regardless of the M1 modifier. A suspected posterior ligamentous injury increased the likelihood of surgeons favoring surgical stabilization.

Risk Stratification of Elderly Patients Undergoing Spinal Surgery Using the Modified Frailty Index.

STUDY DESIGN: Retrospective cohort. OBJECTIVES: To validate the 11-item modified Frailty Index (mFI) as a perioperative risk stratification tool in elderly patients undergoing spine surgery. METHODS: All consecutive cases of spine surgery in patients aged 65 years or older between July 2016 and June 2018 at a state-wide trauma center were retrospectively reviewed. The primary outcome was post-operative major complication rate (Clavien-Dindo Classification ≥ III). Secondary outcome measures included the rate of all complications, 6-month mortality and surgical site infection. RESULTS: A total of 348 cases were identified. The major complication rate was significantly lower in patients with an mFI of 0 compared to ≥ 0.45 (18.3% versus 42.5%, P = .049). As the mFI increased from 0 to ≥ 0.45 there was a stepwise increase in risk of major complications (P < .001). Additionally, 6-month mortality rate was considerably lower when the mFI was 0 rather than ≥ 0.27 (4.2% versus 20.4%, P = .007). Multivariate analysis demonstrated an mFI ≥ 0.27 was significantly associated with an increased incidence of major complication (OR 2.80, 95% CI 1.46-5.35, P = .002), all complication (OR 2.93, 95% CI 1.70-15.11, P < .001), 6-month mortality (OR 7.39, 95% CI 2.55-21.43, P < .001) and surgical site infection (OR 4.43, 95% CI 1.71-11.51, P = .002). The American Society of Anesthesiologists' (ASA) index did not share a stepwise relationship with any outcome. CONCLUSION: The mFI is significantly associated in a gradated fashion with increased morbidity and mortality. Patients with an mFI ≥ 0.27 are at greater risk of major complications, all-complications, 6-monthy mortality, and surgical site infection.

AO Spine upper cervical injury classification system: a description and reliability study.

BACKGROUND CONTEXT: Prior upper cervical spine injury classification systems have focused on injuries to the craniocervical junction (CCJ), atlas, and dens independently. However, no previous system has classified upper cervical spine injuries using a comprehensive system incorporating all injuries from the occiput to the C2-3 joint. PURPOSE: To (1) determine the accuracy of experts at correctly classifying upper cervical spine injuries based on the recently proposed AO Spine Upper Cervical Injury Classification System (2) to determine their interobserver reliability and (3) identify the intraobserver reproducibility of the experts. STUDY DESIGN/SETTING: International Multi-Center Survey. PATIENT SAMPLE: A survey of international spine surgeons on 29 unique upper cervical spine injuries. OUTCOME MEASURES: Classification accuracy, interobserver reliability, intraobserver reproducibility. METHODS: Thirteen international AO Spine Knowledge Forum Trauma members participated in two live webinar-based classifications of 29 upper cervical spine injuries presented in random order, four weeks apart. Percent agreement with the gold-standard and kappa coefficients (ƙ) were calculated to determine the interobserver reliability and intraobserver reproducibility. RESULTS: Raters demonstrated 80.8% and 82.7% accuracy with identification of the injury classification (combined location and type) on the first and second assessment, respectively. Injury classification intraobserver reproducibility was excellent (mean, [range] ƙ=0.82 [0.58-1.00]). Excellent interobserver reliability was found for injury location (ƙ = 0.922 and ƙ=0.912) on both assessments, while injury type was substantial (ƙ=0.689 and 0.699) on both assessments. This correlated to a substantial overall interobserver reliability (ƙ=0.729 and 0.732). CONCLUSIONS: Early phase validation demonstrated classification of upper cervical spine injuries using the AO Spine Upper Cervical Injury Classification System to be accurate, reliable, and reproducible. Greater than 80% accuracy was detected for injury classification. The intraobserver reproducibility was excellent, while the interobserver reliability was substantial.

Variations in management of A3 and A4 cervical spine fractures as designated by the AO Spine Subaxial Injury Classification System.

OBJECTIVE: Optimal management of A3 and A4 cervical spine fractures, as defined by the AO Spine Subaxial Injury Classification System, remains controversial. The objectives of this study were to determine whether significant management variations exist with respect to 1) fracture location across the upper, middle, and lower subaxial cervical spine and 2) geographic region, experience, or specialty. METHODS: A survey was internationally distributed to 272 AO Spine members across six geographic regions (North America, South America, Europe, Africa, Asia, and the Middle East). Participants' management of A3 and A4 subaxial cervical fractures across cervical regions was assessed in four clinical scenarios. Key characteristics considered in the vignettes included degree of neurological deficit, pain severity, cervical spine stability, presence of comorbidities, and fitness for surgery. Respondents were also directly asked about their preferences for operative management and misalignment acceptance across the subaxial cervical spine. RESULTS: In total, 155 (57.0%) participants completed the survey. Pooled analysis demonstrated that surgeons were more likely to offer operative intervention for both A3 (p < 0.001) and A4 (p < 0.001) fractures located at the cervicothoracic junction compared with fractures at the upper or middle subaxial cervical regions. There were no significant variations in management for junctional incomplete (p = 0.116) or complete (p = 0.342) burst fractures between geographic regions. Surgeons with more than 10 years of experience were more likely to operatively manage A3 (p < 0.001) and A4 (p < 0.001) fractures than their younger counterparts. Neurosurgeons were more likely to offer surgical stabilization of A3 (p < 0.001) and A4 (p < 0.001) fractures than their orthopedic colleagues. Clinicians from both specialties agreed regarding their preference for fixation of lower junctional A3 (p = 0.866) and A4 (p = 0.368) fractures. Overall, surgical fixation was recommended more often for A4 than A3 fractures in all four scenarios (p < 0.001). CONCLUSIONS: The subaxial cervical spine should not be considered a single unified entity. Both A3 and A4 fracture subtypes were more likely to be surgically managed at the cervicothoracic junction than the upper or middle subaxial cervical regions. The authors also determined that treatment strategies for A3 and A4 subaxial cervical spine fractures varied significantly, with the latter demonstrating a greater likelihood of operative management. These findings should be reflected in future subaxial cervical spine trauma algorithms.

Tumor characteristics and surgical outcomes of intracranial subependymomas: a systematic review and meta-analysis.

OBJECTIVE: The tumor characteristics and surgical outcomes of intracranial subependymomas are poorly defined. In this study the authors aimed to provide a comprehensive review of all clinical, pathological, radiological, and surgical aspects of this important neoplasm to inform future management strategies. METHODS: A systematic review and meta-analysis of MEDLINE, EMBASE, Cochrane, and Google Scholar databases adherent to PRISMA guidelines was conducted. RESULTS: Of the 1145 articles initially retrieved, 24 studies encompassing 890 cases were included. The authors identified 3 retrospective cohort studies and 21 case series, but no controlled trials. Mean age at presentation was 46.7 ± 18.1 years with a male predominance (70.2%). Common sites of tumor origin were the lateral ventricle (44.5%) and fourth ventricle (43.1%). Cumulative postoperative mortality and morbidity rates were 3.4% and 24.3% respectively. Meta-analysis revealed that male sex (HR 3.15, 95% CI 1.39-7.14, p = 0.006) was associated with poorer 5-year overall mortality rates. All-cause mortality rates were similar when performing subgroup meta-analyses for age (HR 0.50, 95% CI 0.03-7.36, p = 0.61), smaller subependymoma size (HR 1.51, 95% CI 0.78-2.92, p = 0.22), gross-total resection (HR 0.65, 95% CI 0.35-1.23, p = 0.18), and receipt of postoperative radiation therapy (HR 0.88, 95% CI 0.27-2.88, p = 0.84). Postoperative Karnofsky Performance Index scores improved by a mean difference of 1.62 ± 12.14 points (p = 0.42). The pooled overall 5-year survival rate was 89.2%, while the cumulative recurrence rate was 1.3% over a median follow-up ranging from 15.3 to 120.0 months. The pure subependymoma histopathological subtype was most prevalent (85.6%), followed by the mixed subependymoma-ependymoma tumor variant (13.7%). CONCLUSIONS: Surgical extirpation without postoperative radiotherapy results in excellent postoperative survival and functional outcomes in the treatment of intracranial subependymomas. Aggressive tumor behavior should prompt histological reevaluation for a mixed subependymoma-ependymoma subtype. Further high-quality controlled trials are still required to investigate this rare tumor.

Implant Removal Versus Implant Retention Following Posterior Surgical Stabilization of Thoracolumbar Burst Fractures: A Systematic Review and Meta-Analysis.

STUDY DESIGN: Systematic review and meta-analysis. OBJECTIVES: To compare biomechanical and functional outcomes between implant removal and implant retention following posterior surgical fixation of thoracolumbar burst fractures. METHODS: A search of the MEDLINE, EMBASE, Google Scholar and Cochrane Databases was conducted in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. RESULTS: Of the 751 articles initially retrieved, 13 published articles pooling 673 patients were included. Meta-analysis revealed there was a statistically significant improvement in sagittal Cobb Angle by 16.48 degrees (9.13-23.83, p < 0.01) after surgical stabilization of thoracolumbar burst fractures. This correction decremented to 9.68 degrees (2.02-17.35, p < 0.01) but remained significant at the time of implant removal approximately 12 months later. At final follow-up, the implant removal group demonstrated a 10.13 degree loss (3.00-23.26, p = 0.13) of reduction, while the implant retention group experienced a 10.17 degree loss (1.79-22.12, p = 0.10). There was no statistically significant difference in correction loss between implant retention and removal cohorts (p = 0.97). Pooled VAS scores improved by a mean of 3.32 points (0.18 to 6.45, p = 0.04) in the combined removal group, but by only 2.50 points (-1.81 to 6.81, p = 0.26) in the retention group. Oswestry Disability Index scores also improved after implant removal by 7.80 points (2.95-12.64, p < 0.01) at 1 year and 11.10 points (5.24-16.96, p < 0.01) at final follow-up. CONCLUSIONS: In younger patients with thoracolumbar burst fractures who undergo posterior surgical stabilization, planned implant removal results in superior functional outcomes without significant difference in kyphotic angle correction loss compared to implant retention.

The Role of Spinal Orthoses in Osteoporotic Vertebral Fractures of the Elderly Population (Age 60 Years or Older): Systematic Review.

STUDY DESIGN: Systematic review. OBJECTIVE: Spinal orthoses have been generally used in the management of osteoporotic vertebral fractures in the elderly population with purported positive biomechanical and functional effects. To our knowledge, this is the first systematic review of the literature examining the role of spinal orthoses in osteoporotic elderly patients who sustain low energy trauma vertebral fractures. METHODS: A systematic literature review adherent to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was conducted. Methodical searches utilizing MEDLINE, EMBASE, Google Scholar, and Cochrane Databases was performed. RESULTS: Of the 2019 articles initially retrieved, 7 published articles (4 randomized controlled trials and 3 prospective cohort studies) satisfied the inclusion criteria. Five studies reported improvement in quantitative measurements of spinal column stability when either a rigid or semirigid orthosis was used, while 1 study was equivocal. The studies also showed the translation of biomechanical benefit into significant functional improvement as manifested by improved postural stability and reduced body sway. Subjective improvement in pain scores and quality of life was also noted with bracing. CONCLUSION: The use of spinal orthoses in neurologically intact elderly patients aged 60 years and older with osteoporotic compression vertebral fractures results in improved biomechanical vertebral stability, reduced kyphotic deformity, enhanced postural stability, greater muscular strength and superior functional outcomes.

The Effects of Surgery and Adjuvant Therapy on Survival Outcomes in Clear Cell Ependymomas: A Systematic Review and Meta-Analysis of Individual Patient Data.

BACKGROUND: The survival outcomes of clear cell ependymomas are poorly understood. This study clarifies the role of surgery and adjuvant therapy when this morphologically distinct tumor is encountered. METHODS: A systematic search for studies relating to clear cell ependymomas was conducted. Primary outcomes were progression-free survival and overall survival. Prognostic variables were age, sex, tumor consistency, extent of resection, and postoperative adjuvant therapy. Kaplan-Meier survival curves were generated and compared by the log-rank test. Multivariate Cox regression models were constructed, interrogated with Schoenfeld residuals, and used to identify independent prognostic factors. RESULTS: Of the 384 articles retrieved, 8 articles comprising 77 cases of clear cell ependymoma were included. Five-year overall survival and progression-free survival were 58.1% (95% confidence interval [CI], 46.3%-72.9%) and 46.3% (95% CI, 34.2%-62.8%), respectively. Kaplan-Meier analysis with the log-rank test showed that gross total resection was superior to subtotal resection in prolonging survival (P = 0.047) and delayed time to recurrence (P < 0.01). Multivariate analysis confirmed gross total resection as an independent protective factor against relapse (odds ratio, 0.39; 95% CI, 0.17-0.89; P = 0.03). Age <50 years predicted longer overall survival (odds ratio, 0.16; 95% CI, 0.05-0.49; P < 0.01). Postoperative adjuvant therapy after gross total resection did not affect overall survival (P = 0.98) or progression-free survival (P = 0.93). Adjuvant therapy after subtotal resection favored improved overall survival (P = 0.052). CONCLUSIONS: Clear cell ependymomas are particularly aggressive in those aged >50 years. Gross total resection remains the cornerstone of management. Postoperative adjuvant therapy is likely to be of survival benefit only after subtotal resection.

Intracranial peripherally enhancing lesions in cardiac transplant recipients: A rare case series and literature review.

Intracranial peripherally enhancing lesions in immunosuppressed solid organ transplant recipients represent a unique diagnostic and management dilemma due to the vast array of differentials that demand consideration. Diagnosis of the underlying pathology is often guided by the use of magnetic resonance imaging (MRI). We present the first published case series of three cardiac transplant recipients with significantly atypical neuroradiological findings contrary to the tenets of contemporary literature. Our rare case series consists of: (1) A sterile Mycobacterium pyogenic abscess mimicking glioblastoma multiforme due to an immunosuppressed state (2) Epstein Barr Virus encephalitis masquerading as Central Nervous System Post-Transplant Lymphoproliferative Disorder (3) An unusual case of partially treated disseminated Nocardiosis warning of the need to consider the immunosuppressed state and partial treatment response obfuscating classical MRI appearances. We utilise these unprecedented cases as the basis of a literature review to understand the pathophysiology behind the peculiar imaging findings in this rarefied cohort of transplant recipients, and rationalise why the MRI findings in each instance contradicts the accepted imaging patterns. In the setting of potential unreliability of neuroradiology in this immunosuppressed unique subgroup, we hope to impart to clinicians that definitive diagnosis obtained by emergent neurosurgical intervention may be necessary to accurately and expediently guide further medical management.

Successful resolution of the ophthalmic manifestations of a falcotentorial meningioma through Cerebrospinal fluid diversion.

We report the case of a falcotentorial meningioma presenting only with binocular, horizontal diplopia in an otherwise healthy sixty-two-year old male. Review of the established literature highlights a lack of consensus regarding management of this extremely rare pineal region tumor. Complete surgical resection ultimately remains the ideal therapeutic option but surgical excision continues to bear serious risk of neurologic and ophthalmic morbidity, including hemianopia and cortical visual impairment. We advocate that a multidisciplinary approach focusing on patient values is critical in treatment of these uncommon lesions. Cerebrospinal fluid diversion in this patient achieved successful resolution of symptoms secondary to intracranial hypertension whilst facilitating close surveillance.

Metastatic craniocervical hemangiopericytoma presenting with hydrocephalus and papilledema - Case review.

Hemangiopericytomas are rare mesenchymal tumors with propensity to recur locally and metastasize. We report the unique case of a fifty-five-year-old male with recurrence of a previously resected craniocervical hemangiopericytoma presenting with obstructive hydrocephalus secondary to new metastatic cerebellar deposits. Emergent surgical resection of the cerebellar hemangiopericytomas was performed prior to adjuvant radiotherapy. Hemangiopericytomas are rare but important differentials for craniocervical junction lesions. Gross total resection remains the cornerstone of management with post-operative radiotherapy and chemotherapy as potential adjuncts. Tumors located in deep regions pose complex management challenges as safe maximal excision may be limited by proximal eloquent structures.

Prophylaxis of surgical site infection in adult spine surgery: A systematic review.

INTRODUCTION: Surgical site infection (SSI) remains a significant source of morbidity in spine surgery, with reported rates varying from 0.7 to 16%. OBJECTIVE: To systematically review and evaluate the evidence for strategies for prophylaxis of SSI in adult spine surgery in the last twenty years. METHODS: Two independent systematic searches were conducted, at two international spine centers, encompassing PubMed, ClinicalTrials.gov, Cochrane Database, EBSCO Medline, ScienceDirect, Ovid Medline, EMBASE (Ovid), and MEDLINE. References were combined and screened, then distilled to 69 independent studies for final review. RESULTS: 11 randomized controlled trials (RCTs), 51 case-controlled studies (CCS), and 7 case series were identified. Wide variation exists in surgical indications, approaches, procedures, and even definitions of SSI. Intra-wound vancomycin powder was the most widely studied intervention (19 studies, 1 RCT). Multiple studies examined perioperative antibiotic protocols, closed-suction drainage, povidone-iodine solution irrigation, and 2-octyl-cyanoacrylate skin closure. 18 interventions were examined by a single study only. There is limited evidence for the efficacy of intra-wound vancomycin. There is strong evidence that closed-suction drainage does not affect SSI rates, while there is moderate evidence for the efficacy of povidone-iodine irrigation and that single-dose preoperative antibiotics is as effective as multiple doses. Few conclusions can be drawn about other interventions given the paucity and poor quality of studies. CONCLUSIONS: While a small body of evidence underscores a select few interventions for SSI prophylaxis in adult spine surgery, most proposed measures have not been investigated beyond a single study. Further high level evidence is required to justify SSI preventative treatments.

Oculomotor nerve palsy secondary to aberrant posterior cerebral artery.

The authors report a rare case of an oculomotor nerve palsy attributed to mass effect from an aberrant posterior cerebral artery. The patient presented with complete ptosis, mydriasis and ophthalmoplegia of the affected eye. MRI demonstrated distortion of the oculomotor nerve as it traversed inferior to the non-aneurysmal P1 segment of an aberrant posterior cerebral artery. The oculomotor nerve palsy resolved spontaneously.