Presentation on theme: "Daniel S. Chow, MD Jason Talbott, MD"— Presentation transcript:
1 Daniel S. Chow, MD Jason Talbott, MD Mechanism Based Approaches to Identifications of Traumatic Spine InjuryDaniel S. Chow, MDJason Talbott, MD
2 DisclosuresThe authors have no conflicting financial disclosures.
3 Content Organization Background Overview of Classifications Examples by MechanismPost Quiz
4 Background Epidemiology of spine trauma within the US: Incidence: ,500Prevalence: 240,000 to 337,000Mean age: yearsImpact on patients & society:Incomplete tetra- and paraplegia make up 66% of outcomesLifetime cost is variable, but mean yearly expense is estimated at $71,961 per patientNational Spinal Cord Injury Statistical Center, Facts and Figures at a Glance. Birmingham, AL: University of Alabama at Birmingham, 2015.
5 Overview of Spine Trauma Classification Watson & Jones(1938)Holdsworth(1963)AO(1994)19201940196019802000Böhler(1932)Nicoll(1949)Denis & McAfee(1983)TLICS(2005)Böhler1962 – Holdsworth1983 – Denis & mcafee1994- AO2005 TLICSClassification allow for uniform description of injury.Over time, classification of spine injury can broadly be divided intoanatomic changes and mechanism of injury.
6 Title page from Watson & Jones 1938 article Overview of Spine Trauma Classification Böhler, Watson/Jones, and Nicoll1930 – 1949Böhler (1930) described five categories of injury based on mechanism of injury. However, this classification did attempt to identify instability.CompressionShearFlexion – DistractionRotationalExtensionWatson & Jones (1938) evaluated a series of 252 radiographs. Built on Böhler’s study and added:Concept of instability and influence on treatmentImportance of the posterior longitudinal ligament for stabilityBöhler2 initially attempted to classify thoracolumbar spine fractures using five injury types. He combined both anatomic appearance and mechanisms of injury to include compression fractures, flexion-distraction injuries, extension fractures, shear fractures, and rotational injuries in his classification scheme. Böhler, however, did not attempt to define instability patterns based on the anatomical appearance of the injury.Nicoll (1949) evaluated a series of 152 radiographs. Built on prior studies and described an anatomic based classification, stressing the importance of the vertebral body, disc, intervertebral joint, and interspinous ligament.Title page from Watson & Jones 1938 article
7 Overview of Spine Trauma Classification Holdsworth 1962Holdsworth (1962) introduces new classification scheme based on two column model in a review of over 1000 patients who suffered traumatic paraplegia.Stressed the importance of the posterior longitudinal ligament.Böhler2 initially attempted to classify thoracolumbar spine fractures using five injury types. He combined both anatomic appearance and mechanisms of injury to include compression fractures, flexion-distraction injuries, extension fractures, shear fractures, and rotational injuries in his classification scheme. Böhler, however, did not attempt to define instability patterns based on the anatomical appearance of the injury.AnteriorAnt. longitudinal ligamentVertebral bodyIntervertebral discPost. longitudinal ligamentPosteriorPosterior jointInterspinous ligamentSupraspinous ligamentAnterior Posterior
8 Overview of Spine Trauma Classification Denis & McAfee 1983In 1983, Francis Denis introduces a 3-column approachBased on retrospective review of 412 fractures.Combination of both mechanism of injury and anatomy.Compression (4 types)Burst (5 types)Seat Belt (4 types)Fracture – Dislocation (3 types)In 1983, McAfee also describes a 3-column model in 100 patients and also stresses the importance of the middle column.Anterior PosteriorDenis F. The three column spine and its significance in the classification of acute thoracolumbar spinal injuries. Spine (Phila Pa 1976) Nov-Dec;8(8):Baker AD. Classic Papers in Orthopaedics (2013). The Three Column Spine and Its Significance in the Classification of Acute Thoracolumbar Spinal Injuries. ppAnterior Middle Posterior
9 Overview of Spine Trauma Classification Denis & McAfee 1983ProsEasy to understand conceptuallyMost frequently cited (and probably still most frequently used)ConsDoes not account for patient clinical statusDoes not take into account of ligamentous support, which limits accurate assessment of stability.Con: stable vs unstable can be confusion?AnteriorAnt. Longitudinal LigamentAnt. AnnulusAnt. 2/3 Vertebral bodyMiddlePost. Longitudinal LigamentPost. AnnulusPost. 2/3 Vertebral bodyPosteriorPosterior bony elements (pedicles, lamina, spinous process)Posterior ligamentsAnterior Middle Posterior
10 Overview of Spine Trauma Classification Magerl Classification 1994Magerl (1994) introduces new classification scheme based on mechanism on injury and two column model in a review of over 1400 patients.Three types BUT over 50 subtypes (see following slide).CompressionFlexion-ExtensionRotationalReview of 1445 cases3 types with over 50 patternsVery detailed ; however, very complex and not practically reproducibleVery poor reproducibility interobserverProsVery detailedConsiders both fracture pattern and mechanismConsOverly complexPoor reproducibilityDoes not account for clinical status
11 Overview of Spine Trauma Classification Magerl – AO Classification 1994Type A. Vertebral body compressionA1 (Impaction fractures)A1.1 Endplate impactionA1.2 Wedge impact (3)A1.3 Vertebral body collapseA2 (Split fractures)A2.1 Sagittal splitA2.2 Coronal splitA2.3 PincerA3 (Burst fractures)A3.1 Incomplete (3)A3.2 Burst-split (3)A3.3 Complete (3)Type B. Ant & Post Element InjuryB1 Posterior disruption predominantly ligamentous (Flexion-distraction)B1.1 with disruption of disc (3)B1.2 with type A fracture (3)B2 Posterior disruption predominantly osseus (Flexion-distraction)B2.1 Transverse bicolumnB2.2 With disruption of disc (2)B2.3 With type A fracture (2)B3 Ant disc disruption (Hyperextension)B3.1 with subluxation (2)B3.2 with spondylolysisB3.3 with posterior dislocationType C. Ant & Post Element with rotationC1 Type A with rotationC1.1 Rotational wedgeC1.2 Rotation split (4)C1.3 Rotational burst (3)C2 Type B with rotationC2.1 B1 with rotation (7)C2.2 B2 with rotation (3)C2.3 B3 with rotation (3)C3 Rotational - ShearC3.1 Slice fractureC3.2 Oblique fracutre* () indicate number of subtpesMagerl F. A comprehensive classification of thoracic and lumbar injuries. Eur Spine J. 1994;3(4):
12 Overview of Spine Trauma Classification TLICS 2005Spine Trauma Study Group (2005) introduces Thoracolumbar Injury Classification Score, which assigns points based on:Fracture MechanismCompression 1Burst 2Rotational 3Distraction 4Neurologic InvolvementIntact 0Nerve root 2Cord & ConusComplete 2Incomplete 3Conus 3Posterior Ligament ComplexIntact 0Indeterminate 2Injured 3Conservative < 4 points4 points:Indeterminate> 4 points - Operate
13 Overview of Spine Trauma Classification AOSpine TLICS Classification 2013AO Spine TLICS ClassificationTLICSAO (Magerl)The reproducibility and feasibility of evaluating PLC integrity using magnetic resonance imaging (MRI) has been questioned.13,14 Also, the chosen severity scoring system guiding treatment may be a culture- or region-specific decision and may not reflect global surgical preferences or the most rational approach to treatment.The AOSpine Trauma Knowledge Forum, an international group of academic spine surgeons, was tasked to develop and validate a classification system incorporating both fracture morphology and clinical factors relevant for surgical decision making, such as the presence of neurological deficits. The goal of this effort was to develop a widely accepted, comprehen- sive yet simple classification system with clinically acceptable intra- and interobserver reliability to be used for clinical prac- tice and research purposes.agerl classification using an AOSpine database of more than 750 spinal trauma caseIn 2013 the AO Spine Trauma Knowledge Forum combined TLICS with a revised Magerl classification to produce a comprehensive and simple classification scheme
14 Overview of Spine Trauma Classification AOSpine TLICS Classification 2013Type A. Vertebral body compressionA1 Single EndplateA2 PincerA3 Incomplete Burst(Single endplate + Posterior wall)A4 Complete Burst(Both endplates + Posterior wall)Type B. Failure of the posterior or anterior tension bandB1 Posterior Osseus Tension BandB2 Posterior Ligamentous Tension BandB3 Anterior Tension BandType C. Distraction, leading to failure of all elements leading to dislocation ordisplacement in any planeThere are no subtypesClinical StatusN0 Neurologically intactN1 Transient neurological deficitN2 Symptoms or signs of radiculopathyN3 Incomplete spinal cord injury or cauda equina injuryN4 Complete spinal cord injury
15 Examples by mechanismMechanism of injury describes the mechanical mode of failure.Benefits: Knowing mechanism may help classifyLimitations of mechanisms:Does not alone determine stabilityExact mechanism may sometimes be unknown
16 Examples Axial loading with Flexion (Compression) Axial loading with flexion generally leads to compression injury (Type A fractures)Most common type, accounting for up to 90% of cases.The anterior column is compressed, with variable involvement of the remaining middle and posterior columnCompression: Axial loading + FlexionPatient 1:26 year old female in MVA.Sagittal CT demonstrates an anterior compression fracture at T3.
17 Examples Axial loading with Flexion (Compression) Patient 2Sagittal T2 of the thoracic spine demonstrates a compression fracture with single endplate involvement.A1: Single endplate (Green Arrow)B0: Tension bands Intact (Curved Arrow)C0: No Distraction (White arrowhead)Compression: Axial loading + Flexion
18 Examples Axial loading with Flexion (Compression) Patient 3:Sagittal CT of the thoracic spine demonstrates a compression fracture with single endplate involvement.A1: Single endplate (Green arrows)Patient 3Sagittal T2 of the thoracic spine demonstrates a compression fracture with single endplate involvement as well as disruption to the posterior band.A1: Single endplate (Green arrows)B2: Disruption of posterior tension band (Curved yellow line)C0: No Distraction (Red lines)Compression usually from axial + flexionHowever, not all compression fractures are created equal.
19 Examples Compression with Axial loading (Burst) Patient 4:Axial and sagittal CT of the thoracic spine demonstrates an incomplete burst fracture (only superior endplate involved), A3Axial compression generally leads to a burst injury, which may be incomplete (A3) or complete (A4).Typically high energy trauma (i.e. fall from height)Most commonly at the thoracolumbar junction and between T5 through T8.
20 Examples Compression with Axial loading (Burst) Patient 5:Axial and Sagittal CT of the thoracic spine demonstrates a complete burst fracture, involving both endplates as well as the posterior wall.A4: Complete Burst Fracture
21 Examples Compression with Axial loading (Burst) *Patient 5Sagittal T2 of the thoracic spine demonstrates a compression fracture with both endplates involved.A4: Both superior and inferior endplate involvementB0: Tension bands Intact (Curved Arrow)C0: No Distraction
22 Examples Compression with Axial loading (Burst) *Historically, the Denis classification would consider this a two column injury (anterior and middle), which is unstable.However, MRI reveals that the posterior and anterior tensor bands are maintained
23 Examples DistractionPatient 6:Sagittal CT and MR reveals complete failure of all elements leading toDisplacement (Type C injury)Distraction results from separation of the adjacent vertebral bodies.High chance of cord injury once supporting structures (osseous and ligamentous) are pulled separated.While the appearance may be variable, there is no subtypeA distraction injury is separation or pulling apart of two adjacent vertebrae.It is a severe injury since there is a high chance of cord injury when its osseous and ligamentous supporting structures are pulled apart.
24 Examples DistractionPatient 7Sagittal T2 demonstrates complete separation between the thoracic vertebral bodies and ligamentous structures.A0: No compression deformityB: Anterior and Posterior tensor bands are disruptedC: Traumatic anterolisthesis29 year MVA
25 Post Quiz #1 Which of the following is true regarding this injury? The most common type of compression deformityResults from vertical separationUniversally unstableMost commonly located at the thoracolumbar junction
26 Post Quiz #1 Which of the following is true regarding this injury? The most common type of compression deformityResults from vertical separationUniversally unstableMost commonly located at the thoracolumbar junctionExplanation:Depicted is a burst fracture, which is most commonly located at the thoracolumbar junction (Choice D). Briefly, single endplate compression fractures are the most common (Choice A). Distraction injuries arise from separation (Choice B). Lastly, not all burst fractures are unstable (Choice C).
27 Post Quiz #2 Which of the following is true regarding this injury? There are multiple subtypes given variability of this injury.High likelihood of cord injury.Results from axial loading.Can often be managed conservatively.Explanation:Depicted is a distraction injury fracture, which is commonly associated with cord injury (Choice B). Briefly, while there is high variability, these are all considered Type C and there is no subtype. Distraction injuries arise from separation (Choice B). Lastly, distraction injuries are generally unstable (Choice D).
28 ReferencesBohler L. Die techniek de knochenbruchbehandlung imgrieden und im kriege. Verlag von Wilhelm Maudrich 1930 (in German)Watson - JonesS. The results of postural reduction of fractures of the spine. J Bone Joint Surg Am, 1938 Jul; 20 (3):NICOLL EA. Fractures of the dorso-lumbar spine. J Bone Joint Surg Br Aug;31B(3):Holdsworth F. Fractures, dislocations, and fracture-dislocations of the spine. J Bone Joint Surg Am Dec;52(8):Denis F. The three column spine and its significance in the classification of acute thoracolumbar spinal injuries. Spine (Phila Pa 1976) Nov-Dec;8(8):Baker AD. Classic Papers in Orthopaedics (2013). The Three Column Spine and Its Significance in the Classification of Acute Thoracolumbar Spinal Injuries. ppMagerl F. A comprehensive classification of thoracic and lumbar injuries. Eur Spine J. 1994;3(4):Parizel PM, van der Zijden T, Gaudino S, et al. Trauma of the spine and spinal cord: imaging strategies. Eur Spine J Mar;19 Suppl 1:S8-17.Using the popular Denis three-column classification may lead to another situation since it uses the terms stable and unstable. In many cases, however, there is no good correlation with the necessity for surgery.