Cervical Injury Classification Research Articles

Global Validation of the AO Spine Upper Cervical Injury Classification: Erratum.

Global Validation of the AO Spine Upper Cervical Injury Classification: Erratum.

Effect of surgical experience and spine subspecialty on the reliability of the AO Spine Upper Cervical Injury Classification System.

The objective of this paper was to determine the interobserver reliability and intraobserver reproducibility of the AO Spine Upper Cervical Injury Classification System based on surgeon experience (< 5 years, 5-10 years, 10-20 years, and > 20 years) and surgical subspecialty (orthopedic spine surgery, neurosurgery, and "other" surgery). A total of 11,601 assessments of upper cervical spine injuries were evaluated based on the AO Spine Upper Cervical Injury Classification System. Reliability and reproducibility scores were obtained twice, with a 3-week time interval. Descriptive statistics were utilized to examine the percentage of accurately classified injuries, and Pearson's chi-square or Fisher's exact test was used to screen for potentially relevant differences between study participants. Kappa coefficients (κ) determined the interobserver reliability and intraobserver reproducibility. The intraobserver reproducibility was substantial for surgeon experience level (< 5 years: 0.74 vs 5-10 years: 0.69 vs 10-20 years: 0.69 vs > 20 years: 0.70) and surgical subspecialty (orthopedic spine: 0.71 vs neurosurgery: 0.69 vs other: 0.68). Furthermore, the interobserver reliability was substantial for all surgical experience groups on assessment 1 (< 5 years: 0.67 vs 5-10 years: 0.62 vs 10-20 years: 0.61 vs > 20 years: 0.62), and only surgeons with > 20 years of experience did not have substantial reliability on assessment 2 (< 5 years: 0.62 vs 5-10 years: 0.61 vs 10-20 years: 0.61 vs > 20 years: 0.59). Orthopedic spine surgeons and neurosurgeons had substantial intraobserver reproducibility on both assessment 1 (0.64 vs 0.63) and assessment 2 (0.62 vs 0.63), while other surgeons had moderate reliability on assessment 1 (0.43) and fair reliability on assessment 2 (0.36). The international reliability and reproducibility scores for the AO Spine Upper Cervical Injury Classification System demonstrated substantial intraobserver reproducibility and interobserver reliability regardless of surgical experience and spine subspecialty. These results support the global application of this classification system.

An independent inter- and intra-observer agreement assessment of the AOSpine upper cervical injury classification system

BACKGROUND CONTEXTThe complex anatomy of the upper cervical spine resulted in numerous separate classification systems of upper cervical spine trauma. The AOSpine upper cervical classification system (UCCS) was recently described; however, an independent agreement assessment has not been performed. PURPOSETo perform an independent evaluation of the AOSpine UCCS. STUDY DESIGNAgreement study. PATIENT SAMPLEEighty-four patients with upper cervical spine injuries. OUTCOME MEASURESInter-observer agreement; intra-observer agreement. METHODSComplete imaging studies of 84 patients with upper cervical spine injuries, including all morphological types of injuries defined by the AOSpine UCCS were selected and classified by six evaluators (from three different countries). The 84 cases were presented to the same raters randomly after a 4-week interval for repeat evaluation. The Kappa coefficient (κ) was used to determine inter- and intra-observer agreement. RESULTSThe interobserver agreement was almost perfect when considering the fracture site (I, II or III), with κ=0.82 (0.78–0.83), but the agreement according to the site and type level was moderate, κ=0.57 (0.55–0.65). The intra-observer agreement was almost perfect considering the injury, with κ=0.83 (0.78–0.86), while according to site and type was substantial, κ=0.69 (0.67–0.71). CONCLUSIONSWe observed only a moderate inter-observer agreement using this classification. We believe our results can be explained because this classification attempted to organize many different injury types into a single scheme.

Global Validation of the AO Spine Upper Cervical Injury Classification: Geographic Region Affects Reliability and Reproducibility.

Global Survey. To determine the accuracy, interobserver reliability, and intraobserver reproducibility of the AO Spine Upper Cervical Injury Classification System based on surgeons' AO Spine region of practice (Africa, Asia, Central/South America, Europe, Middle East, and North America). A total of 275 AO Spine members assessed 25 upper cervical spine injuries and classified them according to the AO Spine Upper Cervical Injury Classification System. Reliability, reproducibility, and accuracy scores were obtained over two assessments administered at three-week intervals. Kappa coefficients (ƙ) determined the interobserver reliability and intraobserver reproducibility. On both assessments, participants from Europe and North America had the highest classification accuracy, while participants from Africa and Central/South America had the lowest accuracy (P < .0001). Participants from Africa (assessment 1 (AS1):ƙ = .487; AS2:0.491), Central/South America (AS1:ƙ = .513; AS2:0.511), and the Middle East (AS1:0.591; AS2: .599) achieved moderate reliability, while participants from North America (AS1:ƙ = .673; AS2:0.648) and Europe (AS1:ƙ = .682; AS2:0.681) achieved substantial reliability. Asian participants obtained substantial reliability on AS1 (ƙ = .632), but moderate reliability on AS2 (ƙ = .566). Although there was a large effect size, the low number of participants in certain regions did not provide adequate certainty that AO regions affected the likelihood of participants having excellent reproducibility (P = .342). The AO Spine Upper Cervical Injury Classification System can be applied with high accuracy, interobserver reliability, and intraobserver reproducibility. However, lower classification accuracy and reliability were found in regions of Africa and Central/South America, especially for severe atlas injuries (IIB and IIC) and atypical hangman's type fractures (IIIB injuries).

187. An international validation of the AO Spine Upper Cervical Injury Classification

187. An international validation of the AO Spine Upper Cervical Injury Classification

P151. Inspection of the global variability for the AO spine upper cervical injury classification

<h3>BACKGROUND CONTEXT</h3> Previous AO Spine classifications have demonstrated substantial accuracy, interobserver reliability and intraobserver reproducibility regardless of geographic region (as defined by the 6 AO regions of the world – North America, Latin/South America, Africa, Asia and Oceania, Middle East and Europe). However, upper cervical spine injuries are often quickly transferred to academic/tertiary care centers, and as such, may have much greater variability in regional classification ability. The AO Spine Upper Cervical Injury Classification is based on injury level (I. occipital condyle and craniocervical junction, II. C1 and C1-C2 joint, and III. C2 and C2-3 joint) and type of injury (A-bony injury, B-tension band injury, C-fracture dislocation). <h3>PURPOSE</h3> To determine the global variability of the intraobserver reproducibility, interobserver reliability and % agreement compared to the gold-standard (as determined by members of the AO Spine Knowledge Forum Trauma) for the AO Spine Upper Cervical Injury Classification. <h3>STUDY DESIGN/SETTING</h3> Global cross-sectional survey. <h3>PATIENT SAMPLE</h3> A total of 275 AO Spine members. <h3>OUTCOME MEASURES</h3> Precentage agreement with gold-standard, intraobserver reproducibility and interobserver reliability. <h3>METHODS</h3> A total of 275 AO Spine members responded to an open invitation to participate in the AO Spine Upper Cervical Injury Classification validation. A live, online assessment with all participants presenting simultaneously was performed twice at a three-week interval. A total of 25 consecutive upper cervical spine computed tomography (CT) videos, which included axial, sagittal and coronal videos, were played at a rate of 2 frames/second. A REDCap survey was used to capture all participants' classification grades. Pearson's chi square test was used to compare geographic region with significance set at P<0.05. Fleiss' kappa (ƙ) was used to identify the interobserver reliability and intraobserver reproducibility (ƙ=0-0.20 was categorized as slight, 0.21-0.4 was fair, 0.41-0.60 was moderate, 0.61-0.8 was substantial and 0.81-1.0 was excellent). <h3>RESULTS</h3> The majority of participants were from Europe (41.2%) and Asia (23.5%) with the remaining from Central/South America (13.6%), the Middle East (7%), North America (9.5%), and Africa (5.3%). Only 43.6% worked in an academic center and 69.8% worked at a level I trauma center. Participants from Europe, the Middle East, Asia and North America had the highest percentage agreement compared to the gold-standard (range: 75.1-82.9% on both assessments), while Africa and Central/South America (range: 68.9-71.2% on both assessments) had a significantly lower agreement percentage (p<0.001). The interobserver reliability was substantial (ƙ=0.61-0.682) for Asia, Europe, the Middle East, and North America, but it was only moderate for Africa and Central/South America (ƙ=0.487, 0.466, respectively). The intraobserver reproducibility was substantial for North America, Europe, and Asia (ƙ = 0.70, 0.71, 0.61), excellent for the Middle East (ƙ=0.81), and moderate for Africa and Central/South America (0.57 and 0.55, respectively). <h3>CONCLUSIONS</h3> Significant variation in the percentage agreement compared to the gold-standard was identified based on geographic regions. Participants in Africa and South/Latin America regions were less accurate compared to Asia, Europe, South/Latin America and the Middle East. The interobserver reliability and intraobserver reproducibility also showed significant variation between world regions. This may be partly due to less CT scan availability in these regions and the infrequency of these injuries presenting to non-trauma or academic centers, which may make these types of injuries more difficult to accurately identify for some participants. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

The AO spine upper cervical injury classification system: Do work setting or trauma center affiliation affect classification accuracy or reliability?

PurposeTo assess the accuracy and reliability of the AO Spine Upper Cervical Injury Classification System based on a surgeons’ work setting and trauma center affiliation. MethodsA total of 275 AO Spine members participated in a validation of 25 upper cervical spine injuries, which were evaluated by computed tomography (CT) scans. Each participant was grouped based on their work setting (academic, hospital-employed, or private practice) and their trauma center affiliation (Level I, Level II or III, and Level IV or no trauma center). The classification accuracy was calculated as percent of correct classifications, while interobserver reliability, and intraobserver reproducibility were evaluated based on Fleiss’ Kappa coefficient. ResultsThe overall classification accuracy for surgeons affiliated with a level I trauma center was significantly greater than participants affiliated with a level II/III center or a level IV/no trauma center on assessment one (p1<0.0001) and two (p2 = 0.0003). On both assessments, surgeons affiliated with a level I or a level II/III trauma center were significantly more accurate at identifying IIIB injury types (p1 = 0.0007; p2 = 0.0064). Academic surgeons and hospital employed surgeons were significantly more likely to correctly classify type IIIB injuries on assessment one (p1 = 0.0146) and two (p2 = 0.0015). When evaluating classification reliability, the largest differences between work settings and trauma center affiliations was identified in type IIIB injuries. ConclusionType B injuries are the most difficult injury type to correctly classify. They are classified with greater reliability and classification accuracy when evaluated by academic surgeons, hospital-employed surgeons, and surgeons associated with higher-level trauma centers (I or II/III).

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

Background ContextPrior 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. PurposeTo (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/SettingInternational Multi-Center Survey. Patient SampleA survey of international spine surgeons on 29 unique upper cervical spine injuries. Outcome MeasuresClassification accuracy, interobserver reliability, intraobserver reproducibility. MethodsThirteen 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. ResultsRaters 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). ConclusioNSEarly 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.

Fifty years later: the "rule of Spence" is finally ready for retirement.

Determination of the optimal approach to traumatic atlas fractures with or without transverse atlantal ligament (TAL) injury requires a nuanced understanding of the biomechanics of the atlantoaxial complex. The "rule of Spence" (ROS) was created in 1970 in a landmark effort to streamline management of burst-type atlas fractures. The ROS states that radiographic evidence of lateral mass displacement (LMD) (i.e., the distance that the C1 lateral masses extend beyond the C2 superior articular processes) greater than 6.9 mm may indicate both a torn TAL and need for surgical management. Since then, the ROS has become ubiquitous in the spine literature about atlas injuries. However, in the decades since the original paper by Spence et al., modern research efforts and imaging advancements have revealed that the ROS is inaccurate on both fronts: it neither accurately predicts a TAL injury nor does it inform surgical decision-making. The purpose of this review was to delineate the history of the ROS, demonstrate its limitations, present findings in the existing literature on ROS and LMD thresholds, and discuss the current landscape of management techniques for TAL injuries, including parameters such as the atlantodental interval and type of injury according to the Dickman classification system and AO Spine upper cervical injury classification system. The ROS was revolutionary for initially investigating and later propelling the biomechanical and clinical understanding of atlas fractures and TAL injuries; however, it is time to retire its legacy as a rule.

Global Validation of the AO Spine Upper Cervical Injury Classification.

Global cross-sectional survey. To determine the classification accuracy, interobserver reliability, and intraobserver reproducibility of the AO Spine Upper Cervical Injury Classification System based on an international group of AO Spine members. Previous upper cervical spine injury classifications have primarily been descriptive without incorporating a hierarchical injury progression within the classification system. Further, upper cervical spine injury classifications have focused on distinct anatomical segments within the upper cervical spine. The AO Spine Upper Cervical Injury Classification System incorporates all injuries of the upper cervical spine into a single classification system focused on a hierarchical progression from isolated bony injuries (type A) to fracture dislocations (type C). A total of 275 AO Spine members participated in a validation aimed at classifying 25 upper cervical spine injuries through computed tomography scans according to the AO Spine Upper Cervical Classification System. The validation occurred on two separate occasions, three weeks apart. Descriptive statistics for percent agreement with the gold-standard were calculated and the Pearson χ 2 test evaluated significance between validation groups. Kappa coefficients (κ) determined the interobserver reliability and intraobserver reproducibility. The accuracy of AO Spine members to appropriately classify upper cervical spine injuries was 79.7% on assessment 1 (AS1) and 78.7% on assessment 2 (AS2). The overall intraobserver reproducibility was substantial (κ=0.70), while the overall interobserver reliability for AS1 and AS2 was substantial (κ=0.63 and κ=0.61, respectively). Injury location had higher interobserver reliability (AS1: κ = 0.85 and AS2: κ=0.83) than the injury type (AS1: κ=0.59 and AS2: 0.57) on both assessments. The global validation of the AO Spine Upper Cervical Injury Classification System demonstrated substantial interobserver agreement and intraobserver reproducibility. These results support the universal applicability of the AO Spine Upper Cervical Injury Classification System. 4.

Innovations in cervical spine trauma: Developing the next generation upper cervical spine injury classification system

The upper cervical spine not only consists of intricate bony and ligamentous anatomy affording unique flexibility but also has increased susceptibility to injuries. The upper cervical spine trauma can result in a wide spectrum of injuries that can be managed both operatively and nonoperatively. Several existing classification systems have been proposed to describe injuries of the upper cervical spine, many of which rely on anatomic descriptions of injury location. Prior fracture classifications are limited in scope, characterizing fractures restricted to a single region of the upper cervical spine, and fail to provide insight into injury management. The AO Spine Upper Cervical Injury Classification System (AO Spine UCCS) has recently been developed as a comprehensive, yet concise classification scheme to describe all injuries of the upper cervical spine. The AO Spine UCCS represents a significant development in the classification of upper cervical spine injuries, with the potential to serve as a decision-making instrument to aid in patient management.

A multilevel noncontiguous spinal fracture with cervical and thoracic spinal cord injury.

Introduction and importanceA multi-level non-contiguous spinal fracture (MNSF) caused by a high-energy impact is a type of complex traumatic injury that is been frequently initially missed, and resulting in delayed diagnosis which adversely affects can result in spinal deformity and neurological deficit. This report describes the operative management of a patient with MNSF with spinal cord injury involving the cervical and thoracic vertebrae by cervical orthosis and posterior thoracic decompression and fusion.Case presentationAn 18-year-old male presented with extensive neck pain and paraplegia (ASIA A), following a motor vehicle accident. Radiographic imaging revealed MNSF: a non-displaced spinous process fracture of C5 (AO Spine subaxial cervical injury classification A0) with spinal cord injury combined with fracture-dislocation of T5 to T9 (AO Spine thoracolumbar injury classification C3). Posterior thoracic decompression and fusion was performed at T3 to T8. After the patient underwent the thoracic spine and cervical orthosis treatment, He received rehabilitation program and training transfer with wheelchair without caregiver. His sitting and balance were significantly improved at the 6 months follow-up. Although the lower extremity functions (ASIA A) may not improve due to the severe spinal cord injury.Clinical discussionMNSF with spinal cord injury following a high-velocity accident is an unstable and complex injury. Important of the clinical assessment and according to the injuries the treatment may vary.ConclusionsCervical orthosis was alternative treatment to preserve cervical motion treatment and posterior thoracic decompression with fixation is an effective option for patients in this MNSF with spinal cord injury.

Update on Upper Cervical Injury Classifications: The New AO Upper Cervical Spine Classification System.

The upper cervical spine accounts for the largest proportion of cervical range of motion afforded by a complex system of bony morphology and ligamentous stability. Its unique anatomy, however, also makes it particularly vulnerable during both low and high energy trauma. Trauma to this area, referred to as upper cervical spine trauma, can disrupt the stability of the upper cervical spine and result in a wide spectrum of injury. Numerous upper cervical injury classification systems have been proposed, each of which have distinct limitations and drawbacks that have prevented their universal adoption. In this article, we provide an overview of previous classifications, with an emphasis on the development of the new AO Spine Upper Cervical Classification System (AO Spine UCCS).

Risk Factors for Poor Prognosis of Cervical Spinal Cord Injury with Subaxial Cervical Spine Fracture-Dislocation After Surgical Treatment: A CONSORT Study.

BackgroundThe objective of the study was to identify risk factors for poor prognosis of cervical spinal cord injury (SCI) with subaxial cervical fracture-dislocation after surgical treatment.Material/MethodsA total of 60 cervical SCI patients with subaxial cervical fracture-dislocation were primarily included in the study from April 2013 to April 2018. All the enrolled subjects received surgical treatment. The enrolled patients with complete follow-up record were divided into 2 groups based on the neural function prognosis: a non-functional restoration group and a functional restoration group. Multivariate regression analysis was performed to identify independent risk factors for poor prognosis of SCI after surgical treatment.ResultsFifty-five subjects were included in this study, and the follow-up time ranged from 8.5 to 44.5 months. A total of 25 subjects were categorized into the non-functional restoration group and 30 subjects into the functional restoration group. According to the results of multivariate regression analysis, time from injury to operation (more than 3.8 days), subaxial cervical injury classification (SLIC, score more than 7.5), and maximum spinal cord compression (MSCC, more than 55.8%) are independent risk factors for poor prognosis of SCI after surgical treatment (p<0.05), with AUCs of 0.95 (time from injury to operation), 0.91 (SLIC score), and 0.96 (MSCC).ConclusionsTime from injury to operation (more than 3.8 days), SLIC score (more than 7.5), and MSCC (more than 55.8%) are independent risk factors for poor prognosis of SCI with subaxial cervical fracture-dislocation after surgical treatment.

Surgical Practice in Traumatic Spinal Fracture Treatment with Regard to the Subaxial Cervical Injury Classification and Severity and the Thoracolumbar Injury Classification and Severity Systems: A Review of 58 Patients at the University of Wisconsin

Spine surgeons at a Level 1 Trauma Center have observed a high incidence of spine and spinal cord injuries owing to falls from tree stands. These injuries have been retrospectively reviewed in the context of the Thoracolumbar Injury Classification and Severity (TLICS) and the Subaxial Cervical Injury Classification and Severity (SLICS) classification systems to assess inter-user reliability and validity. We hypothesize that the inter-rater reliability will be similar between neuroradiology and neurosurgery raters and validity of the scoring system will be maintained at our institution. The University of Wisconsin Hospital and Clinics' trauma database was reviewed for tree stand-related injuries from 1999 to 2013, with a focus on patients suffering from spine and spinal cord injuries. The TLICS and SLICS scores were then independently determined for these injuries by a neurosurgeon and a neuroradiologist. When cases were grouped by management recommendation (operative, equivocal, and nonoperative) reviewer agreement was 12/15 (80%) of SLICS and 38/52 (73%) of TLICS scores. Operative SLICS positive predictive value reached 100%, however, with a wide confidence interval. Conversely, the SLICS negative predictive value was poor at 54%-60%, with frequent operative treatment for patients assigned nonoperative scores. TLICS scores reached 77.8% and 93.3% positive predictive value per reviewer, whereas negative predictive values reached 93.9% and 89.2%, respectively. The TLICS and SLICS systems provide good-to-excellent inter-rater reliability. SLICS validity was poor, whereas TLICS was reasonable for nonoperative cases and moderate for operative cases. Systems such as the TLICS and the SLICS may be best applied in the educational setting to confirm the fracture morphology and presence or absence of ligamentous injury between surgeons and radiologists.

Subaxial cervical spine injury classification system: is it most appropriate for classifying cervical injury?

Subaxial cervical spine injury classification system: is it most appropriate for classifying cervical injury?

Classification and Surgical Decision Making in Acute Subaxial Cervical Spine Trauma

Retrospective case series, literature review. To describe and apply an optimal classification system for the management of subaxial cervical trauma. Traumatic injury to the subaxial cervical trauma is common yet diagnosis and treatment choices remain controversial. The lack of a widely accepted classification system contributes to the variation in care. Two clinically relevant questions pertaining to the subaxial spine were developed by consensus from a panel of fellowship-trained spine trauma surgeons. A literature review identified published treatment algorithms for subaxial cervical trauma. Consecutive cases presenting to 2 tertiary trauma centers representing a spectrum of commonly observed, clinically relevant injury patterns were analyzed and the subaxial cervical injury classification system (SLIC) applied. Three representative clinical scenarios of subaxial trauma are presented to demonstrate utilization of the treatment algorithm. Literature review identified only 1 classification and treatment algorithm that met all inclusion criteria. Sixty-five consecutive subaxial cervical trauma cases were identified from which 10 representative injury patterns were selected and described according to the SLIC classification system. This was applied to clinical scenarios and treatment algorithms derived. The SLIC system can be used to reliably and effectively classify subaxial cervical trauma. The treatment algorithm described by Dvorak et al, Spine 2007;32:2620-9, can be used to guide surgical decision-making including surgical approach and the sequence of procedures based on injury type.