Reliability of the evaluation of posterior ligamentous complex injury in thoracolumbar spine trauma with the use of computed tomography scan

Reliability of thoracolumbar burst fracture classification in the Swedish Fracture Register

BACKGROUND

The Swedish Fracture Register (SFR) is a national quality register for all types of fractures in Sweden. Spine fractures have been included since 2015 and are classified using a modified AOSpine classification. The aim of this study was to determine the accuracy of the classification of thoracolumbar burst fractures in the SFR.

METHODS

Assessments of medical images were conducted in 277 consecutive patients with a thoracolumbar burst fracture (T10-L3) identified in the SFR. Two independent reviewers classified the fractures according to the AOSpine classification, with a third reviewer resolving disagreement. The combined results of the reviewers were considered the gold standard. The intra- and inter-rater reliability of the reviewers was determined with Cohen's kappa and percent agreement. The SFR classification was compared with the gold standard using positive predictive values (PPV), Cohen's kappa and percent agreement.

RESULTS

The reliability between reviewers was  high (Cohen's kappa 0.70-0.97). The PPV for correctly classifying burst fractures in the SFR was high irrespective of physician experience (76-89%), treatment (82% non-operative, 95% operative) and hospital type (83% county, 95% university). The inter-rater reliability of B-type injuries and the overall SFR classification compared with the gold standard was low (Cohen's kappa 0.16 and 0.17 respectively).

CONCLUSIONS

The SFR demonstrates a high PPV for accurately classifying burst fractures, regardless of physician experience, treatment and hospital type. However, the reliability of B-type injuries and overall classification in the SFR was found to be low. Future studies on burst fractures using SFR data where classification is important should include a review of medical images to verify the diagnosis.

Computed Tomography Findings and Classification of Traumatic Lumbosacral Spine Injuries: Insights from the AOSpine Classification System

Purpose

The main objective of this study was to provide a description and classification of lumbosacral spine injuries based on the new AOSpine classification system.

Methods

A cross-sectional study was conducted on 75 patients with lumbosacral spine trauma who were admitted to Hue University of Medicine and Pharmacy Hospital in Hue, Vietnam, between April 2021 and July 2022. All patients underwent lumbosacral computed tomography, and each injured vertebra was classified according to the AOSpine classification system. The frequency and percentage of subtypes of lumbosacral spine trauma were determined.

Results

The mean age of the patients was 50.6 ± 16.1 years, and the male-to-female ratio was 1.5:1. Falls and traffic accidents were found to be the main causes of injuries. Among the patients, 78.7% did not exhibit any neurological symptoms, while 1.3% experienced complete hemiplegia and 20% had incomplete hemiplegia. The most common fracture subtype was A3, accounting for 34.6% of cases.

Conclusion

This study provides valuable insights into the demographics, associated injuries, and classification of traumatic lumbosacral spine injuries based on the new AOSpine classification system. The study found that falls and motor vehicle accidents were the main causes of these injuries, with a higher proportion of male patients. The majority of injuries were classified as type A fractures, while type C fractures were the least common. Sacral fractures were relatively infrequent and often associated with pelvic ring fractures. These findings contribute to our understanding of lumbosacral spine trauma and can aid in the development of more effective treatment protocols.

A Proposal for a Standardized Imaging Algorithm to Improve the Accuracy and Reliability for the Diagnosis of Thoracolumbar Posterior Ligamentous Complex Injury in Computed Tomography and Magnetic Resonance Imaging

STUDY DESIGN

Systematic Literature Review.

OBJECTIVE

To propose a systematic imaging algorithm for diagnosing posterior ligamentous complex (PLC) injury in computed tomography (CT) and magnetic resonance imaging (MRI) to improve the reliability of PLC assessment.

METHODS

A systematic review was conducted following PRISMA guidelines. The Scopus database was searched from its inception until July 21, 2022, for studies evaluating CT or MRI assessment of the PLC injury following thoracolumbar trauma. The studies extracted key findings, objectives, injury definitions, and radiographic modalities.

RESULTS

Twenty-three studies were included in this systematic review, encompassing 2021 patients. Five studies evaluated the accuracy of MRI in detecting thoracolumbar PLC injury using intraoperative findings as a reference. These studies indicate that black stripe discontinuity due to supraspinous or ligamentum flavum rupture is a more specific criterion of PLC injury than high-signal intensity. Thirteen papers evaluated the accuracy or reliability of CT in detecting thoracolumbar PLC injury using MRI or intraoperative findings as a reference. The overall accuracy rate of CT in detecting PLC injury was 68-90%. Two studies evaluate the accuracy of combined CT findings, showing that ≥2 CT findings are associated with a positive predictive value of 88-91 %. Vertebral translation, facet joint malalignment, spinous process fracture, horizontal laminar fracture, and interspinous widening were independent predictors of PLC injury.

CONCLUSION

We provided a comprehensive imaging algorithm for diagnosing PLC in CT and MRI based on available literature and our experience. The algorithm will potentially improve the accuracy and reliability of PLC assessment, however it needs multicentre prospective validation.

Which Morphological Features of Facet Diastasis Predict Thoracolumbar Posterior Ligamentous Complex Injury as Defined by Magnetic Resonance Imaging?

BACKGROUND

The association of various morphological features of facet diastasis with posterior ligamentous complex (PLC) injury has not been previously described. This study aims to determine the diagnostic value of facet diastasis subtypes for diagnosing thoracolumbar PLC injury.

METHODS

We retrospectively reviewed 337 consecutive patients with acute thoracolumbar fractures who had computed tomography (CT) and magnetic resonance imaging (MRI) within 10 days of injury. Three and 5 reviewers evaluated MRI and CT images, respectively. Facet diastasis was subclassified as follows: Dislocated, no articular surface apposition; subluxed, incomplete articular surface apposition; and facet fracture articular process fractures which may be displaced ≥2 mm or otherwise undisplaced, facet joint widening (FJW) ≥ 3 mm. We examined the diagnostic accuracy and the multivariate associations of facet diastasis subtypes with PLC injury in MRI.

RESULTS

Facet dislocation, subluxation, and displaced facet fracture yielded a high positive predictive value (PPV) for PLC injury (96%, 88%, and 94%, respectively). In contrast, undisplaced facet fracture and FJW yielded a moderate PPV for PLC injury (78%, and 45%, respectively). Facet dislocation, subluxation, and displaced facet fracture showed independent associations with PLC injury (adjusted odds ratio [AOR] = 38.4, 17.1, 13.4, respectively; P < 0.05). Undisplaced facet fracture and FJW were not associated with PLC injury (AOR = 3.9 [95% confidence interval, 0.49-38.4], P = 0.20) and (AOR = 1.94 [95% confidence interval, 0.48-7.13]; P = 0.20; P = 0.33), respectively.

CONCLUSIONS

Facet dislocation, subluxation, and displaced facet fracture, but not undisplaced facet fracture or FJW, were independently associated with PLC injury. Therefore, we propose to define facet diastasis as a surrogate marker of PLC injury in MRI based on these morphologies.

Thoracolumbar spine trauma: a guide for the FRCS examination

Thoracolumbar spine injuries are commonly seen in trauma settings and have a high risk of causing serious morbidity. There can be controversy when it comes to classifying thoracolumbar injuries within the spinal community, but there remains a need to classify, evaluate and manage thoracolumbar fractures. This article aims to provide a guide on classification of thoracolumbar spine injuries using the AO Spine Thoracolumbar Injury Classification System (AO TLICS).

Is the AO spine thoracolumbar injury classification system reliable and practical? a systematic review

Controversy surrounding the classification of thoracolumbar injuries has given rise to various classification systems over the years, including the most recent AOSpine Thoracolumbar Injury Classification System (ATLICS). This systematic review aims to provide an up-to-date evaluation of the literature, including assessment of a further three studies not analysed in previous reviews. In doing so, this is the first systematic review to include the reliability among non-spine subspecialty professionals and to document the wide variety between reliability across studies, particularly with regard to sub-type classification. Relevant studies were found via a systematic search of PubMed, EBESCO, Cochrane and Web of Science. Data extraction and quality assessment were conducted in line with Cochrane Collaboration guidelines. Twelve articles assessing the reliability of ATLICS were included in this review. The overall inter-observer reliability varied from fair to substantial, but the three additional studies in this review, compared to previous reviews, presented on average only fair reliability. The greatest variation of results was seen in A1 and B3 subtypes. Least reliably classified on average was A4 subtype. This systematic review concludes that ATLICS is reliable for the majority of injuries, but the variability within subtypes suggests the need for further research in assessing the needs of users in order to increase familiarity with ATLICS or perhaps the necessity to include more subtype-specific criteria into the system. Further research is also recommended on the reliability of modifiers, neurological classification and the application of ATLICS in a paediatric context.

Load-Sharing Classification Score as Supplemental Grading System in the Decision-Making Process for Patients With Thoracolumbar Injury Classification and Severity 4

BACKGROUND

Patients with Thoracolumbar Injury Classification and Severity (TLICS) score of 4 fall into a gray zone between surgical and conservative management. The integrity of posterior ligamentous complex (PLC) evaluated by magnetic resonance imaging (MRI) contributes to surgical decision-making. Load-sharing classification (LSC) may provide a modifier to further guide decision-making in these patients.

OBJECTIVE

To evaluate associations between LSC score and MRI acquisition, compromise of PLC on MRI, and surgical intervention in TLICS 4 patients.

METHODS

A cohort of 111 neurologically intact patients with isolated thoracolumbar burst fracture with TLICS 4 was evaluated. LSC score was determined based on degree of comminution (1-3), apposition (1-3), and kyphosis (1-3), total composite score of 3 to 9.

RESULTS

Overall, 44 patients underwent MRI, 15 had PLC injury, and 32 (28.8%) underwent surgery. LSC score was higher in patients who had an MRI (median 6 vs 3, P < .001) and patients who had surgery (median 7 vs 4, P < .001). In univariate logistic regression, LSC score was associated with MRI acquisition (odds ratio [OR] 1.7; 1.32-2.12; P < .001), presence of PLC injury on MRI (OR 1.5; 1.2-2.0; P = .002) and, in multivariate logistic regression, undergoing surgical intervention (OR 3.7; 2.3-5.9; P < .001), independent of MRI or PLC injury.

CONCLUSION

LSC score in neurologically intact patients with isolated thoracolumbar burst fracture with TLICS 4 was independently associated with operative intervention. The application of LSC may further guide decision-making in this patient group.

Assessment of Interobserver Variability for CT Scan-Based Evaluation of Posterior Ligament Complex Injury in Thoracolumbar Fractures: An International Multicenter Pilot Study

STUDY DESIGN

A multicenter, pilot study, for radiological assessment of thoracolumbar spine fractures was performed with the participation of 7 centers in Africa, Europe, Asia, and South America as a part of the AO Foundation network.

OBJECTIVES

To determine the interobserver variability for computed tomography (CT) scan-based evaluation of posterior ligament complex (PLC) injury in thoracolumbar fractures.

METHODS

Forty-two observers including 1 principal investigator at each participating center performed variability assessment. Each center contributed toward a total of 91 patient images with A3 or A4 thoracolumbar burst fractures (T11-L2) with or without suspected PLC injury. Pathological fractures, multilevel injuries, obvious posterior bony element injury and translation/dislocation injuries were excluded. Ten patients were randomly selected and commonly reported CT parameters indicating PLC injury, including superior inferior endplate angle, vertebral body height loss, local kyphotic deformity, interspinous distance and interpedicular distance were assessed for variability. Observer values were compared with an experienced gold rater in spinal trauma. Analysis of variability was performed for all observers, between the principal investigators and also between observers participating in each center.

RESULTS

The studied parameters showed considerable variability in measurements among all observers and amongst all participating centers. The variability between the principal investigators was lower, but still substantial. The deviation of observer measurements from the gold rater were also significant for all CT parameters.

CONCLUSIONS

CT-based radiological parameters previously reported to be suggestive of PLC injury showed considerable variability and magnetic resonance imaging verification of a PLC injury in all doubtful cases is suggested.

Reliability of the New AOSpine Classification System for Upper Cervical Traumatic Injuries

BACKGROUND

The new AOSpine Upper Cervical Classification System (UCCS) was recently proposed by the AOSpine Knowledge Forum Trauma team to standardize the treatment of upper cervical traumatic injuries (UCI). In this context, evaluating its reliability is paramount prior to clinical use.

OBJECTIVE

To evaluate the reliability of the new AOSpine UCCS.

METHODS

A total of 32 patients with UCI treated either nonoperatively or with surgery by one of the authors were included in the study. Injuries were classified based on the new AO UCCS according to site and injury type using computed tomography scan images in 3 planes by 8 researchers at 2 different times, with a minimum interval of 4 wk between assessments. Intra- and interobserver reliability was assessed using the kappa index (K). Treatment options suggested by the evaluators were also assessed.

RESULTS

Intraobserver agreement for sites ranged from 0.830 to 0.999, 0.691 to 0.983 for types, and 0.679 to 0.982 for the recommended treatment. Interobserver analysis at the first assessment was 0.862 for injury sites, 0.660 for types, and 0.585 for the treatment, and at the second assessment, it was 0.883 for injury sites, 0.603 for types, and 0.580 for the treatment. These results correspond to a high level of agreement of answers for the site and type analysis and a moderate agreement for the recommended treatment.

CONCLUSION

This study reported an acceptable reproducibility of the new AO UCCS and safety in recommending the treatment. Further clinical studies with a larger patient sample, multicenter and international, are necessary to sustain the universal and homogeneity quality of the new AO UCCS.

Isolated multiple lumbar transverse process fractures with spinal instability: an uncommon yet serious association

PURPOSE

Isolated vertebral transverse process fractures of thoracolumbar spine without other vertebral injuries and neurological deficit are generally considered as minor injuries with no concern for associated spinal instability. This report describes a case of multiple lumbar transverse fractures associated with an unexpected yet clinically significant spinal instability.

METHODS

A young male presented with right flank pain following being pushed and trapped against the ground by a reversing truck. The neurological examination was normal, and computed tomography (CT) imaging revealed multiple fractures at right transverse processes from L1 to L5, a single left-sided transverse process fracture at L2 and subtle facet joint distraction without other spinal lesions or visceral injuries. The injury was initially deemed as stable requiring symptomatic treatment and in-patient observation. However, discharge upright X-rays taken in a brace showed marked subluxation of L2/L3 and L3/L4 levels.

RESULTS

Magnetic resonance imaging revealed significant discoligamentous injuries involving anterior and posterior longitudinal ligaments, annulus fibrosus as well as posterior ligamentous complex. The patient underwent posterior spinal instrumentation and fusion of L1 to L5.

CONCLUSIONS

This is the first case description of association of multisegmental lumbar transverse process fractures with notoriously unstable injuries of the major soft-tissue stabilizers of the spine presenting subtle changes on CT images. When a seemingly benign spinal injury is caused by high-energy trauma, careful scrutiny for associated instability is needed. In this case, the standing in-brace X-ray was able to avoid a misdiagnosis and potentially unfavourable outcome.

Reliability and Validity of the AOSpine Thoracolumbar Injury Classification System: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVES

The AOSpine thoracolumbar injury classification system (ATLICS) is a relatively simple yet comprehensive classification of spine injuries introduced in 2013. This systematic review summarizes the evidence on measurement properties of this new classification, particularly the reliability and validity of the main morphologic injury types with and without inclusion of the subtypes.

METHODS

A literature search was performed using PubMed and Embase in September 2016. A revised version of the COSMIN checklist was used for evaluation of the quality of studies. Two independent reviewers performed all steps of the review.

RESULTS

Nine articles were included in the final review, all of which evaluated the reliability of the ATLICS and had a fair methodological quality. The reliability of the modifiers was unknown. Overall, the quality of evidence for reliability of the morphologic and neurologic classification sections was low. However, there was moderate evidence for poor interobserver reliability of the morphologic classification when all subtypes were included, and moderate evidence for good intraobserver reliability with exclusion of subtypes. The reliability of the morphologic classification was independent of the observer's experience and cultural background.

CONCLUSIONS

ATLICS represents the most current system for evaluation of thoracolumbar injuries. Based on this review, further studies with robust methodological quality are needed to evaluate the measurement properties of ATLICS. Shortcomings of the reliability studies are discussed.

Is focused magnetic resonance imaging adequate for treatment decision making in acute traumatic thoracic and lumbar spine fractures seen on whole spine computed tomography?

PURPOSE

To assess whether a focused magnetic resonance imaging (MRI) limited to the region of known acute traumatic thoracic or lumbar fracture(s) would miss any clinically significant injuries that would change patient management.

STUDY DESIGN/SETTING

A multicenter retrospective clinical study.

PATIENT SAMPLE

Adult patients with acute traumatic thoracic and/or lumbar spine fracture(s).

OUTCOME MEASURES

Pathology identified on MRI (ligamentous disruption, epidural hematoma, and cord contusion), outside of the focused zone, an alteration in patient management, including surgical and nonsurgical, as a result of the identified pathology outside the focused zone.

METHODS

Records were reviewed for all adult trauma patients who presented to the emergency department between 2008 and 2016 with one or more fracture(s) of the thoracic and/or lumbar spine identified on computed tomography (CT) and who underwent MRI of the entire thoracic and lumbar spine within 10 days. Exclusion criteria were patients with >4 fractured levels, pathologic fractures, isolated transverse, and/or spinous process fractures, prior vertebral augmentation, and prior thoracic or lumbar spine instrumentation. Patients with neurologic deficits or cervical spine fractures were also included. MRIs were reviewed independently by one spine surgeon and one musculoskeletal fellowship-trained emergency radiologist for posterior ligamentous complex (PLC) integrity, vertebral injury, epidural hematoma, and cord contusion. The surgeon also commented on the clinical significance of the pathology identified outside the focused zone. All cases in which pathology was identified outside of the focused zone (three levels above and below the fractures) were independently reviewed by a second spine surgeon to determine whether the pathology was clinically significant and would alter the treatment plan.

RESULTS

In total, 126 patients with 216 fractures identified on CT were included, with a median age of 49 years. There were 81 males (64%). Sixty-two (49%) patients had isolated thoracolumbar junction injuries and 36 (29%) had injuries limited to a single fractured level. Forty-seven (37%) patients were managed operatively. PLC injury was identified by both readers in 36 (29%) patients with a percent agreement of 96% and κ coefficient of 0.91 (95% CI 0.87-0.95). Both readers independently agreed that there was no pathology identified on the complete thoracic and lumbar spine MRIs outside the focused zone in 107 (85%) patients. Injury outside the focused zone was identified by at least one reader in 19 (15%) patients. None of the readers identified PLC injury, cord edema, or noncontiguous epidural hematoma outside the focused zone. Percent agreement for outside pathology between the two readers was 92% with a κ coefficient of 0.60 (95% CI 0.48-0.72). The two spine surgeons independently agreed that none of the identified pathology outside of the focused zone altered management.

CONCLUSIONS

A focused MRI protocol of three levels above and below known thoracolumbar spine fractures would have missed radiological abnormality in 15% of patients. However, the pathology, such as vertebral body edema not appreciated on CT, was not clinically significant and did not alter patient care. Based on these findings, the investigators conclude that a focused protocol would decrease the imaging time while providing the information of the injured segment with minimal risk of missing any clinically significant injuries.

A Case of Delayed Paraplegia Following Missed Diagnosis on Computed Tomography

There are many proposed classification systems for traumatic thoracolumbar fractures (TLF). More recently published are the AO Spine Classification System and the Thoraco-Lumbar Injury Classification System (TLICS). There has been a paucity of high-level evidence to link these classification system subtypes with clinical outcomes and/or management strategies. Previously, post-traumatic burst fractures or two column injuries identified on computed tomography (CT) scan have been deemed stable injuries. The addition of magnetic resonance imaging (MRI) evaluation for concomitant ligamentous injuries in cases of incomplete burst fractures has been widely debated without high-level evidence. In this report, we present a case of an incomplete burst fracture at L1, AO-A3, which did not receive an MRI and presented with delayed paraplegia four weeks later.

Percutaneous pedicle screw fixation plus kyphoplasty for thoracolumbar fractures A2, A3 and B2

DESIGN

Retrospective cohort.

PURPOSE

The aim of this study is to evaluate the effectiveness of percutaneous short fixation (PSFx) plus kyphoplasty (BP) for thoracolumbar fractures.

METHODS

Thirty-six consecutive selected patients, aged 59 ± 17 years, with fresh single thoracolumbar A₂, A₃, and B₂ AO-type fracture, received PSFx plus BP. The primary outcomes pain, and vertebral body deformity; and the secondary outcomes screw malposition, facet violation, PMMA leakage, adjacent segment degeneration (ASD) and loss of correction were evaluated. The f/up was 31 ± 7 months.

RESULTS

Pain and kyphosis decreased and vertebral body heights increased significantly postoperation. PMMA leakage occurred in five cases; 6 (4 %) screws were grades III malpositioned in relation to pedicle; facet violation occurred in 8 (5.5 %) facets; loss of kyphosis correction was 3.68°; ASD occurred in two cases; interfacet fusion in ten (28 %) patients; Three patients were reoperated for different reasons.

CONCLUSIONS

PSFx plus BP for thoracolumbar fractures reduces significantly spinal deformity and pain with few complications.