Presentation on theme: "Cervical Spine Workshop"— Presentation transcript:
1Cervical Spine Workshop Chris Dillon, MDRegions Emergency Medicine Residency Program
2Why is this important?Cervical spine injuries are both common and potentially devastating.Incidence(USA)7,000 to 10,000 patients with cervical spine injuries who present for treatment annually.An estimated 5,000 additional patients with cervical spine injuries die at the scene of the accident.Half of cervical spine injuries are associated with spinal cord injury.Consequences of neck injuries range from simple neck pain, to quadriplegia, or even deathSpinal cord injury occurs at the time of trauma in 85% of patients and as a late complication in 15%.Delayed recognition of an injury or improper stabilization of the cervical spine may lead to irreversible spinal cord injury and permanent neurologic damage.
3Who and whySpinal cord injury most often occurs in teenagers and young adults.Mean age 30.7, most commonly occurs at age 1982% malesmotor vehicle accident (50%)falls (25%)sports injuries (10%).
4Cost Direct costs for the first year after injury High of $417,067 for ventilator dependent quadriplegics patients to a low of $122,914 in the group with near normal neurologic function.Indirect costs often greatly exceed the direct costs.
5We see these patients every day Due to high morbidity and mortality of injuriesRegions Hospital EMS Guidelines“Backboard patient with C-collar if patient complains of head, neck, or back pain, or if suggested by mechanism of injury, or if history is unreliable due to unconsciousness or altered mental status.”
7Upper Cervical Spine Injuries Most common injury is flexion.Fracture of odontoid process.Extension injuries may occur, but are rare.Rotation-rare, possible unilateral facet joint dislocation.Axial loading-fracture of thinner parts of atlas anteriorly and posteriorlyNeurologic deficit is rare because of size of vertebral foramen.
8The atlas articulates with the occipital condyle superiorly and the axis inferiorly. Atlanto-occipital articulation is important in the flexion and extension of the neck.Atlas-axis articulation is important in the lateral rotation of the neck.
9Lower Cervical Spine Injuries C3-C7 Spinal Canal less spaciousInjuries associated with forces applied to spineFlexion-Dislocated facets and fracture.Extension-Damage to anterior structures and compression of posterior structures.Facet joints at 45º-lateral rotation is limited, but injuries may still occur.Axial loading-combined with flexion injury.
10Normal Anatomy-C4 Typical cervical vertebra of C3 - C7. Vertebral body is equal in height anteriorly and posteriorly.Vertebra articulates with the next vertebra at the body and the articular processes.Vertebral artery passes through the transverse foramen.
11StabilityThe determination of whether a given injury is stable is extremely important in the initial evaluation of cervical spine trauma. The stability of the cervical spine is provided by the two vertical columns.Anterior column consists of the vertebral bodies, the disc spaces, the anterior and posterior longitudinal ligaments and annulus fibrosus.Posterior column consists of the pedicles, facets and apophyseal joints, laminar spinous processes and the posterior ligament complex.Generally speaking, if one of the two columns is intact, the injury is stable, if both columns are disrupted, the injury is unstable.
12Plain filmsPlain films provide the quickest way to survey the cervical spineAn adequate spine series includes three views:true lateral view (which must include all seven.cervical vertebrae as well as the C7-T1 junction)AP view.open-mouth odontoid view.
13Lateral ViewThe single most important radiographic examination of the acutely injured cervical spine is the horizontal-beam lateral radiograph that is obtained before patient is moved. This film should be obtained and examined before any other films are taken. All 7 cervical vertebrae and C7-T1 junction must be visualized because the cervicothoracic junction is a common place for traumatic injury. Visualization of C7-T1 may be limited by the amount of soft tissue in the shoulder region and can be enhanced by: 1. traction on arms if no arm injury is present, or, 2. swimmer's view (taken with one arm extended over the head).
16AP and Open-Mouth Views The complete radiographic examination includes AP and open-mouth views. If there are no obvious fractures or dislocations on the lateral view and the patient's condition permits, then proceed with the AP and the open-mouth views. It is important to obtain technically adequate films. The most frequent cause of overlooked injury is an inadequate film series. Patient should be maintained in cervical immobilization, and plain films should be repeated or CT scans obtained until all vertebrae are clearly visible. The AP view and Odontoid view are obtained as follows
20CTUp to 20 % of fractures are missed on conventional radiographs. CT can help. CT scan is not mandatory for every patient with cervical spine injury. Most injuries can be diagnosed by plain films. However, if there is a question on the radiograph, CT of the cervical spine should be obtained. CT scan are particularly useful in fractures that result in neurologic deficit and in fractures of the posterior elements of the cervical canal (e.g. Jefferson's fracture) because the axial display eliminates the superimposition of bony structures. The advantages of CT are: 1. CT is excellent for characterizing fractures and identifying osseous compromise of the vertebral canal because of the absence of superimposition from the transverse view. The higher contrast resolution of CT also provides improved visualization of subtle fractures. 2. CT provides patient comfort by being able to reconstruct images in the axial, sagittal, coronal, and oblique planes from one patient positioning. The limitations of CT are: 1. difficult to identify those fractures oriented in axial plane (e.g. dens fractures). 2. unable to show ligamentous injuries. 3. relatively high costs. Sagittal, coronal, 3D reconstructions are possible.
22MRIMRI is indicated in cervical fractures that have spinal canal involvement, clinical neurologic deficits or ligamentous injuries. MRI provides the best visualization of the soft tissues, including ligaments, intervertebral disks, spinal cord, and epidural hematomas. The advantages of MRI are: 1. excellent soft tissue constrast, making it the study of choice for spinal cord survey, hematoma, and ligamentous injuries. 2. provides good general overview because of its ability to show information in different planes (e.g. sagital, coronal, etc.). 3. ability to demostrate vertebral arteries, which is useful in evaluating fractures involving the course of the vertebral arteries. 4. no ionizing radiation. The disadvantages of MRI are: 1. loss of bony details. 2. relatively high cost. Here is an example of a MRI image of the cervical spine demostrating a ligamentous injury. Notice that the spinal cord is also very well delinated. A dens fracture is not obvious on the lateral film, but is clearly revealed on MRI.
24Evaluation of images A adequacy A alignment B bone C cartilage D disc S soft tissue
25Lateral View The lateral view is the most important film of all. Interpretation follows the mnemonic AABCDS.First, is the film Adequate?An adequate film should include all 7 vertebrae and C7-T1 junction.It should also have correct density and show the soft tissue and bony structures well.
27AlignmentAssess four parallel lines. These are: 1. Anterior vertebral line (anterior margin of vertebral bodies) 2. Posterior vertebral line (posterior margin of vertebral bodies) 3. Spinolaminar line (posterior margin of spinal canal) 4. Posterior spinous line (tips of the spinous processes) These lines should follow a slightly lordotic curve, smooth and without step-offs. Any malalignment should be considered evidence of ligmentous injury or occult fracture, and cervical spine immobilization should be maintained until a definitive diagnosis is made.
29Bony LandmarksTrace the unbroken outline of each vertebrae (including Odontoid on C2). The vertebral bodies should line up with a gentle arch (normal cervical lordosis) using the anterior and posterior marginal lines on the lateral view. Each body should be rectangular in shape and roughly equal in size although some variability is allowed (overall height of C4 and C5 may be slightly less than C3 and C6) . The anterior height should roughly equal posterior height (posterior may normally be slightly greater, up to 3mm).
31Bony LandmarksPedicles project posteriorly to support the articular pillars, forming the superior and inferior margins of the intervertebral foramen. The left and right pedicels should superimpose on true lateral views. If fracture is suspected, get oblique views or CT.Facets: the articular pillars are osseous masses connected to the posterolateral aspect of vertebral bodies via the pedicles. The facet joints are formed between each lateral mass. On the lateral view, the lateral masses appear as rhomboid-shaped structures projecting downward and posterior. "Double cortical lines" results from slight obliquity from lateral projection. The distance of the joint space should be roughly equal at all levels.Lamina: the posterior elements are seen poorly on the lateral film. They are best demostrated by CT.Spinous process: generally get progressively larger in the lower vertebral bodies. The C7 cervical spine is usually the largest.
33Cartilaginous SpaceThe Predental space (distance from dens to C1 body) should not measure more than 3 mm in adults and 5mm in children. If the space is increased, a fracture of the Odontoid process or disruption of the transverse ligament is likely. If fracture is suspected, CT should be obtained. If ligamentous disruption is suspected, a MRI should be obtained.Predental space should be:< 3 mm in adults.
35Disc SpacesDisc spaces should be roughly equal in height at anterior and posterior margins.Disc spaces should be symmetric.Disc space height should also be approximately equal at all levels. In older patients, degenative diseases may lead to spurring and loss of disc height.
37Soft Tissue SpacePreverteral soft tissue swelling is important in trauma because it is usually due to hematoma formation secondary to occult fractures. Unfortunately, it is extremely variable and nonspecific. Maximum allowable thickness of preverteral spaces is as follows: Nasopharyngeal space (C1) - 10 mm (adult) Retropharyngeal space (C2-C4) mm Retrotracheal space (C5-C7) - 14 mm (children), 22 mm (adults). Soft tissue swelling in symptomatic patients should be considered an indication for further radiographic evaluation. If the space between the lower anterior border of C3 and the pharyngeal air shadow is > 7 mm, one should suspect retropharyngeal swelling (e.g. hemorrhage). This is often a useful indirect sign of a C2 fracture. Space between lower cervical vertebrae and trachea should be < 1 vertebral body.
39AP ViewAlignment on the A-P view should be evaluated using the edges of the vertebral bodies and articular pillars. The height of the cervical vertebral bodies should be approximately equal on the AP view. The height of each joint space should be roughly equal at all levels. Spinous process should be in midline and in good alignment. If one of the spinous process is displaced to one side, a facet dislocation should be suspected.
41Odontoid View Adequate? An adequate film should include the entire odontoid and the lateral borders of C1-C2.Alignment?Occipital condyles should line up with the lateral masses and superior articular facet of C1. The distance from the dens to the lateral masses of C1 should be equal bilaterally Any asymmetry is suggestive of a fracture of C1 or C2 or rotational abnormality. It may also be caused by tilting of the head, so if the vertebrae is shifted in on one side, then it should be shifted out on the other side. The tips of lateral mass of C1 should line up with the lateral margins of the superior articular facet of C2. If not, a fracture of C1 should be suspected.Bony Margins. the Odontoid should have uninterrupted cortical margins blending with the body of C2.
43Mechanism of InjuryThe cervical spine may be subjected to forces of different directions and magnitude. The most common mechanisms of cervical spine injury are hyperflexion, hyperextension and compression.
44HyperflexionExcessive flexion of the neck in the sagital plane. It results in disruption of the posterior ligament. A common cause of hyperflexion injury is diving in shallow water, which may result in flexion tear drop fracture.
45HyperextensionExcessive extension of the neck in the sagital plane. A common cause of hyperextension injury is hitting the dash board in MVA, which may result in Hangman's fracture.
46Axial compressionForce applied directly over the vertex in the caudal direction. This compression force "like smashing a cracker" may result in Jefferson fracture, a bursting fracture on the atlas.
47Atlanto-occipital Disassociation Description: Disruption of the atlanto-occipital junction involving the atlanto-occipital articulations. Mechanism: Hyperflexion or hyperextension. Radiographic features: 1. Malposition of occipital condyles in relation to the superior articulating facets of the atlas. 2. Increased ratio of Basion - spinolaminar line of C1 to Opisthion - posterior cortex of C1 anterior arch for incomplete anterior atlanto-occipital dislocation. (Refer to atlanto-occipital alignment for further explaination). 3. Cervicocranial prevertebral soft tissue swelling. Stability: unstable
49Jefferson FractureDescription: compression fracture of the bony ring of vertebra C1, characterized by lateral masses splitting and transverse ligament tear. Mechanism: axial blow to the vertex of the head (e.g. diving injury). Radiographic features: the key radiographic view is the AP open mouth, which shows displacement of the lateral masses of vertebrae C1 beyond the margins of the body of vertebra C2. A lateral displacement of >2 mm or unilateral displacement may be indicative of a C1 fracture. CT is required to define the extent of fracture and to detect fragments in the spinal canal. Stability: unstable
52Odontoid FracturesRadiographic features: fracture is best seen on lateral view. Fracture of the odontoid should be suspected if there is an anterior tilt of odontoid on lateral view. The lucent fracture line may be better delineated by plain film tomogram or CT. Sometimes the only sign of fracture may be just prevertebral soft tissue swelling. Odontoid fractures are generally divided into three types.
53Dens Fracture Type IType I Odontoid fracture: fracture in superior tip of the odontoid.Potentially unstable.Rare fracture.
54Dens Fracture Type IIType II Odontoid Fracture: fracture at base of odontoid.most common type of odontoid fracture.unstable fracture.
58Hangman's FractureDescription: fractures through the pars interaticularis of the axis resulting from hyperextension and distraction. Mechanism: hyperextension (e.g. hanging, chin hits dashboard in MVA). Radiographic features: (best seen on lateral view) 1. Prevertebral soft tissue swelling. 2. Avulsion of anterior inferior corner of C2 associated with rupture of the anterior longitudinal ligament. 3. Anterior dislocation of the C2 vertebral body. 4. Bilateral C2 pars interarticularis fractures. Stability: unstable
60Flexion Teardrop Fracture Description: posterior ligament disruption and anterior compression fracture of the vertebral body which results from a severe flexion injury. Mechanism: hyperflexion and compression (e.g. diving into shallow water) Radiographic features: (best seen on lateral view) 1. Prevertebral swelling associated with anterior longitudinal ligament tear. 2. Teardrop fragment from anterior vertebral body avulsion fracture. 3. Posterior vertebral body subluxation into the spinal canal. 4. Spinal cord compression from vertebral body displacement. 5. Fracture of the spinous process. Stability: unstable
63Bilateral Facet Dislocation Description: complete anterior dislocation of the vertebral body resulting from extreme hyperflexion injury. It is associated with a very high risk of cord damage. Mechanism: extreme flexion of head and neck without axial compression. Radiographic features: (best seen on lateral view) 1. Complete anterior dislocation of affected vertebral body by half or more of the vertebral body AP diameter. 2. Disruption of the posterior ligament complex and the anterior longitudinal ligament. 3. "Bow tie" or " bat wing" appearance of the locked facets. Stability: unstable
65Unilateral Facet Dislocation Description: facet joint dislocation and rupture of the apophyseal joint ligaments resulting from rotatory injury of the cervical vertebrae. Mechanism: simultaneous flexion and rotation Radiographic features: (best seen on lateral or oblique views) 1. Anterior dislocation of affected vertebral body by less than half of the vertebral body AP diameter. 2. Discordant rotation above and below involved level. 3. Facet within intervertebral foramen on oblique view. 4. Widening of the disk space. 5. "Bow tie" or "bat wing" appearance of the overriding locked facets. Stability: stable
67Anterior SubluxationDescription : disruption of the posterior ligamentous complex resulting from hyperflexion. It may be difficult to diagnose because muscle spasm may result in similar findings on the radiograph. Subluxation may be stable initially, but it associates with 20%-50% delayed instability. Flexion and extension views are helpful in further evaluation. Mechanism: hyperflexion of neck Radiographic features: 1. Loss of normal cervical lordosis. 2. Anterior displacement of the vertebral body. 3. Fanning of the interspinous distance. Radiographic features of unstable injury: 1. Anterior subluxation of more than 4mm. 2. Associated compression fracture of more than 25 % of the affected vertebral body. 3. Increase or decrease in normal disk space. 4. Fanning of the interspinous distance.
68Clay Shoveler's Fracture Description: fracture of a spinous process C6-T1 Mechanism: powerful hyperflexion, usually combined with contraction of paraspinous muscles pulling on spinous processes (e.g. shoveling). Radiographic features: (best seen on lateral view) 1. Spinous process fracture on lateral view. 2. Ghost sign on AP view (i.e. double spinous process of C6 or C7 resulting from displaced fractured spinous process). Stability: stable
72Burst FractureDescription: fracture of C3-C7 that results from axial compression. Injury to spinal cord, secondary to displacement of posterior fragments, is common. CT is required for all patient to evaluate extent of injury. Mechanism: axial compression Stability: stable
75ManagementGeneral Principles Outcome for the spine trauma patient often depends upon action taken by the emergency team in the first 6 to 12 hours after injury. The main objective in cervical trauma management is to prevent cord injury and to minimize any secondary injuries to spinal cord tissue as a result of inadequate immobilization, persistent spinal cord compression, poor blood flow or oxygenation. The goal is to optimize the environment for the spinal cord to recover as much as possible.If a cervical fracture or dislocation is found. Orthopedic or neurosurgical consultation should be obtained immediately.There are three indications for surgical intervention in cervical spine trauma.Neurologic deficitSpinal instabilityIntractable pain
76ManagementSome fractures, such as unilateral facet dislocation, may required skeletal traction and reduction. Physicians should perform these procedures with minimum amont of sedation so that the patient can provide instant neurologic feedback.High suspicion for cervical fracture should be maintained in all trauma situations because there are no signs of neurologic injury in many cervical fractures. Cervical immobolization is usually achieved by a Philadelphia-type collar or a halo vest.
78Management of Specific Fractures Jefferson fracture is treated with halo immobilization for 12 weeks, which usually results in primary union of the ring of C1 and stability of C1 with respect to C2. Surgical fusion may be needed if there is atlantoaxial instability after removal of halo.Hangman's fracture is unstable. It usually heals with halo immobilization for 12 weeks. Surgical fusion is rarely indicatedOdontoid fracture:Type I is rare. It usually does not have any neurologic symptoms. It is treated with Philadelphia collar.Type II is the most difficult type to treat in the halo vest. Even with proper management, the nonunion rate is still as high as 30-60%. If nonunion persists, surgical posterior fusion is indicated.Type III is treated with halo immobilization. It usually has a high rate of union.
79Management of Specific Fractures Fractures and dislocations of lower cervical spine:Vertical compression fractures are normally treated initially with traction to reduce fragmentation and subsequently with halo vest. They tend to heal well with halo immobilization .Unilateral facet dislocations do fairly well with halo immobilization.Bilateral facet dislocations are treated conservatively. The facet joints are reduced and immobilized. The posterior ligament usually heals poorly.Clay Shoveler's fractures are treated with soft collar for comfort. Prognosis is excellent.
80Who needs imaging?Not all trauma patients with a significant injury need c-spine films.
81Canadian C-spine RuleContext High levels of variation and inefficiency exist in current clinical practice regarding use of cervical spine (C-spine) radiography in alert and stable trauma patients.Objective To derive a clinical decision rule that is highly sensitive for detecting acute C-spine injury and will allow emergency department (ED) physicians to be more selective in use of radiography in alert and stable trauma patients.Design Prospective cohort study conducted from October 1996 to April 1999, in which physicians evaluated patients for 20 standardized clinical findings prior to radiography. In some cases, a second physician performed independent interobserver assessments.Setting Ten EDs in large Canadian community and university hospitals.Patients Convenience sample of 8924 adults (mean age, 37 years) who presented to the ED with blunt trauma to the head/neck, stable vital signs, and a Glasgow Coma Scale score of 15.Main Outcome Measure Clinically important C-spine injury, evaluated by plain radiography, computed tomography, and a structured follow-up telephone interview. The clinical decision rule was derived using the coefficient, logistic regression analysis, and 2 recursive partitioning techniques.Results Among the study sample, 151 (1.7%) had important C-spine injury. The resultant model and final Canadian C-Spine Rule comprises 3 main questions: (1) is there any high-risk factor present that mandates radiography (ie, age 65 years, dangerous mechanism, or paresthesias in extremities)? (2) is there any low-risk factor present that allows safe assessment of range of motion (ie, simple rear-end motor vehicle collision, sitting position in ED, ambulatory at any time since injury, delayed onset of neck pain, or absence of midline C-spine tenderness)? and (3) is the patient able to actively rotate neck 45° to the left and right? By cross-validation, this rule had 100% sensitivity (95% confidence interval [CI], 98%-100%) and 42.5% specificity (95% CI, 40%-44%) for identifying 151 clinically important C-spine injuries. The potential radiography ordering rate would be 58.2%.Conclusion We have derived the Canadian C-Spine Rule, a highly sensitive decision rule for use of C-spine radiography in alert and stable trauma patients. If prospectively validated in other cohorts, this rule has the potential to significantly reduce practice variation and inefficiency in ED use of C-spine radiography.JAMA. 2001;286:
82Canadian C-spine RuleFor patients alert w/GCS=15, stable (SBP>90, RR=10-24):(1) Any high risk factor that mandates xray?--age>65 y/o or--dangerous mechanism (fall>5 stairs, axial load to head, mvc>60 mph, rollover, ejection) or--paresthesias in ext**if yes then xray; if no then #2(2) Any low risk factor that allows safe assessment of ROM--simple rear-end mvc or--sitting position in ED or--ambulatory at any time or--delayed onset of neck pain or--absence of midline c-spine tend**lf no then xray; lf yes then to #3(3) Able to actively rotate neck 45 degrees left & right?**if no then xray; if yes then no xray
83NEXUS (National Emergency X-ray Utilization Study) Background: Because clinicians fear missing occult cervical-spine injuries, they obtain cervical radiographs for nearly all patients who present with blunt trauma. Previous research suggests that a set of clinical criteria (decision instrument) can identify patients who have an extremely low probability of injury and who consequently have no need for imaging studies.Methods: We conducted a prospective, observational study of such a decision instrument at 21 centers across the United States. The decision instrument required patients to meet five criteria in order to be classified as having a low probability of injury: no midline cervical tenderness, no focal neurologic deficit, normal alertness, no intoxication, and no painful, distracting injury. We examined the performance of the decision instrument in 34,069 patients who underwent radiography of the cervical spine after blunt trauma.Results: The decision instrument identified all but 8 of the 818 patients who had cervical-spine injury (sensitivity, 99.0 percent [95 percent confidence interval, 98.0 to 99.6 percent]). The negative predictive value was 99.8 percent (95 percent confidence interval, 99.6 to 100 percent), the specificity was 12.9 percent, and the positive predictive value was 2.7 percent. Only two of the patients classified as unlikely to have an injury according to the decision instrument met the preset definition of a clinically significant injury (sensitivity, 99.6 percent [95 percent confidence interval, 98.6 to 100 percent]; negative predictive value, 99.9 percent [95 percent confidence interval, 99.8 to 100 percent]; specificity, 12.9 percent; positive predictive value, 1.9 percent), and only one of these two patients received surgical treatment. According to the results of assessment with the decision instrument, radiographic imaging could have been avoided in the cases of 4309 (12.6 percent) of the 34,069 evaluated patients.Conclusions: A simple decision instrument based on clinical criteria can help physicians to identify reliably the patients who need radiography of the cervical spine after blunt trauma. Application of this instrument could reduce the use of imaging in such patients.N Engl J Med 2000;343:94-9.
84NEXUSRadiography is not recommended if a patient meets all of the following criteria:Absence of tenderness at the posterior midline of the C-spineAbsence of a focal neurologic deficitNormal level of alertnessNo evidence of intoxicationAbsence of clinically apparent pain that might distract the patient from the pain of a C-spine injury
85ComparisonAmong the 8283 patients, 169 (2.0 percent) had clinically important cervical-spine injuries. In 845 (10.2 percent) of the patients, physicians did not evaluate range of motion as required by the CCR algorithmprospective cohort study in nine Canadian emergency departments comparing the CCR and NLC as applied to alert patients with trauma who were in stable conditionCCR was more sensitive than the NLC (99.4 percent vs percent, P<0.001) and more specific (45.1 percent vs percent, P<0.001For alert patients with trauma who are in stable condition, the CCR is superior to the NLC with respect to sensitivity and specificity for cervical-spine injury, and its use would result in reduced rates of radiography
86Clinical clearance Evaluate Strength Sensation Tenderness ROM ?image
89ReferencesStiell IG, Wells GA, Vandemheen K, et al. The Canadian Cervical Spine Radiography Rule for alert and stable trauma patients. JAMA 2001;286:Stiell IG, Clement C, McKnight RD, et al. The Canadian C-Spine Rule versus the NEXUS low-risk criteria in patients with trauma. N Engl J Med 2003;349:N Engl J Med 2000;343:94-9.JAMA. 2001;286: