Spine Flashcards
Presentation of central cord syndrome
Motor: weakness of UE with lesser effect on LE
Sensory: varying degrees of disturbance below lesion
Myelopathic findings: sphincter dysfunction (usually urinary retention)
Etiology of central cord syndrome
Usually seen following acute hyperextension injury in an older patient with pre-existing stenosis from bony hypertrophy
May occur +/- cervical fracture or dislocation
Guidelines for acute central cord injuries
- maintain MAP 85-90 mmHg for the 1st week
- early reduction of fracture-dislocation injuries
- surgical decompression (for progressive deterioration- usually decompressive lami +/- fusion)
Etiology of anterior cord syndrome
Cord infarction in the territory supplied by the anterior spinal artery, may also result from anterior cord compression by dislocated bone fragment or traumatic herniated disc
Presentation of anterior cord syndrome
Paraplegia (if higher than C7 then quadriplegia)
Dissociated sensory loss below lesion: loss of pain/temp (spinothalamic) with preserved 2-point discrimination, joint position, deep pressure (posterior columns)
Classic findings of Brown-Sequard syndrome
Ipsilateral findings: motor paralysis, loss of proprioception and vibration
Contralteral findings: loss of pain and temp, preserved light touch (due to redundant ipsilateral and CL paths, anterior spinothalamic tracts)
Classification of atlanto-occipital dislocations
Type 1: anterior dislocation of occiput relative to the atlas
Type 2: longitudinal dislocation (distraction)
Type 3: posterior dislocation of occiput
Grisel syndrome
AA rotatory subluxation secondary to an infection of the head or neck (usually a retropharnyngeal abscess)
Classification of C1 fractures
Type 1: fractures involving a single arch
Type 2: burst fracture (classic Jefferson fracture)
Type 3: lateral mass fractures of the atlas
Definition of Jefferson fracture
Classically a 4 point burst fracture of the C1 ring, with bilateral fractures to the anterior and posterior arches, usually from axial load compression
Guidelines for isolated atlas fractures
If the transverse ligament is intact: cervical immobilization alone
If the transverse ligament is disrupted: either cervical immobilization alone or surgical fixation and fusion
Definition of Hangman’s fracture
Bilateral fracture through the pars interarticularis of C2 with traumatic subluxation of C2 on C3, most often due to hyperextension + axial loading
Guidelines for isolated Hangmans’ fracture
May initially be managed with external immobilizations
Surgical stabilization in the case of: severe angulation of C2 on C3, disruption of C2-3 disc space, or inability to establish or maintain alignment with external immobilization
Most common mechanism of odontoid fractures
Flexion is the most common mechanism of injury, with resultant anterior displacement of C1 on C2 (AA subluxation)
Classification of odontoid fractures
Type 1: avulsion of the attachment of the alar ligament
Type 2: through the base of the neck, the most common dens fracture
Type 2A: similar to type 2 but with large bone chips at the fracture site
Type 3: through body of C2
Clay Shoveler’s Fracture
Avulsion of spinous processes (usually C7)
This fracture is stable.
Mechanism of teardrop fracture
Results from hyperflexion or axial loading at the vertex of the skull with the neck flexed (eliminating the normal cervical lordosis)
Lhermitte sign
Cervical flexion/extension leads to shocklike sensation radiating down spinal axis and into arms/legs
Specific but not sensitive for cervical spinal cord compression and myelopathy
Nerve root injury that produces Trendelenburg gait
Injury to L5 nerve root
Composition of annulus fibrosis
Type 1 collagen that is obliquely oriented, water, and proteoglycans
High collagen/low proteoglycan ratio
Composition of nucleus pulposis
Type 2 collagen, water, and proteoglycans
Low collagen/high proteoglycan ratio
Mechanism of neurogenic shock
Circulatory collapse from loss of sympathetic tone leads to decreased systemic vascular resistance, pooling of blood in extremities, and hypotension
Treatment of neurogenic shock
Swan-Ganz monitoring for careful fluid management
Pressors to treat hypotension
Presentation of spinal shock
Flaccid areflexic paralysis, bradycardia, hypotension, absent bulbocavernosus reflux
Most common cardiac arrhythmia in acute stage following SCI
Sinus bradycardia
Definition of syringomyelia
A syrinx within the spinal cord that progressively expands and leads to neurologic deficits
Definition of syringobulbia
A syrinx within the brain stem that leads to neurologic symptoms
Symptoms of syringobulbia
Symptoms related to CN involvement - tongue weakness and atrophy (CN XII), SCM and trap weakness (CN XI), dysphagia and dysarthria (CN IX, X), facial palsy (CN VII)
Definition of diastematomyelia
A fibrous, cartilagenous, or osseous bar creating a longitudinal cleft in the spinal cord
Most common intradural extramedullary tumors
Schwannoma, meningioma
Common location of intradural extramedullary Schwannomas
Arise from dorsal nerve root
Cervical spine (31%), cauda equina (24%), thoracic spine (22%)
Histology of intradural extramedullary Schwannomas
Biphasic, Antoni A (hypercellular) and B (hypocellular) pattern
Treatment of intradural extramedullary Schwannomas
Surgical resection
Post-operative radiation for malignant tumors
Most common location for intradural extramedullary meningiomas
Thoracic spine
Most common intradural intramedullary tumors
Ependymoma and astrocytoma
Imaging characteristics of intradural intramedullary ependymomas
On MRI, encapsulated lesion in the filum terminale
T1 - hypo or iso-intense
T2 - hyper-intense
Imaging characteristics of intradural intramedullary astrocytomas
On MRI, fusiform appearance with irregular margins
T1 - hypo or iso-intense
T2 - hyper-intense with variable contrast enhancement
Typically found in cervicothoracic junction in children
Common extradural tumors
Mets (lung, breast) and lymphoma
Imaging characteristics of extradural lymphoma
T2 - ill-defined hyperintense lesions with marked homogenous contrast enhancement
Usually found in cervical spine
Treatment of extradural lymphoma
Methotrexate
Symptoms of cauda equina syndrome
Bilateral leg pain
Bowel and bladder dysfunction (urinary retention and eventually overflow incontinence)
Saddle anesthesia
Lower extremity sensorimotor changes
Causes of cauda equina
Disc herniation (most common), spinal stenosis, tumors, trauma, spinal epidural hematoma, epidural abscess
Treatment of cauda equina
Urgent surgical decompression within 48 hours (diskectomy, laminectomy)
Anderson and Montesano Classification of occipital condyle fractures - type 1
Impaction type fracture with comminution of the occipital condyle
Due to compression between the atlanto-odontoid joint
Stable injury
Anderson and Montesano Classification of occipital condyle fractures - type 2
Basilar skull fracture that extends into one or both occipital condyles
Due to a direct blow to skull
Stable injury
Anderson and Montesano Classification of occipital condyle fractures - type 3
Avulsion fracture of condyle in region of the alar ligament attachment
Due to forced rotation with combined lateral bending
Has the potential to be unstable due to craniocervical disruption
Presentation of occipital condyle fractures
High cervical pain Reduced head/neck ROM Torticollis Lower CN deficits (most commonly IX, X and XI) Motor paresis
Operative indications for occipital condyle fractures
Type 3 with overt instability
Neural compression from displaced fracture fragment
Associated occipital-atlantal or atlanto-axial injuries
Measurement used to diagnose occipitocervical dislocation
Powers ratio = C-D/A-B
C-D (distance from basion to posterior arch)
A-B (distance from anterior arch to opisthion)
Normal ratio is about 1
If > 1 = anterior dislocation
Type 1 atlas fracture
Isolated anterior or posterior arch fracture
Type 2 atlas fracture
Jefferson burst fracture with bilateral fractures of anterior and posterior arch resulting from axial load
Stability determined by integrity of transverse ligament
Type 3 atlas fracture
Unilateral lateral mass fracture
Stability determined by integrity of transverse ligament
Type 1 transverse ligament injury
Intersubstance tear
Type 2 transverse ligament injury
Bony avulsion
Non-operative treatment for atlas fractures
Hard cervical orthosis vs halo immobilization for 6-12 weeks for stable type 1, stable Jefferson, stable type 3
Indications for operative treatment of atlas fractures
Unstable type 2 and type 3 fractures (both controversial)
Technique - posterior C1-C2 fusion vs occipitocervical fusion
Blood supply to the odontoid
Apex is supplied by branches of ICA
Base is supplied by branches of vertebral artery
Vascular watershed area in between - thought to affect healing of type II fractures
Type 1 odontoid fracture
Oblique avulsion fracture of tip of odontoid
Due to avulsion of alar ligament
Type 2 odontoid fracture
Fracture through waist - high nonunion rate due to vascular watershed area
Type 3 odontoid fracture
Fracture extends into cancellous body of C2 and involves a variable portion of the C1-C2 joint
Treatment of type 1 odontoid fractures
Cervical orthosis
Treatment of type 2 odontoid fractures in younger patients
Halo immobilization if no risk factors for nonunion
Surgery if risk factors for nonunion
Treatment for type 2 odontoid fractures in elderly patients
Cervical orthosis if not surgical candidates
Surgery if surgical candidates
Treatment of type 3 odontoid fractures
Cervical orthosis
Operative procedure for odontoid fractures
Posterior C1-C2 fusion
Definition of Hangman’s fracture
Traumatic anterior spondylolithesis of the axis due to bilateral fracture of pars interarticularis
Type 1 occipitocervical dislocation
Anterior occiput dislocation
Type 2 occipitocervical dislocation
Superior occiput dislocation
Type 3 occipitocervical dislocation
Posterior occiput dislocation
Harris rule of 12 for occipitocervical dislocation
Basion-dens interval > 12 mm suggests occipitocervical dislocation
Flexion teardrop fracture
Characterized by fracture of anterior inferior portion of vertebra, posterior portion of vertebra retropulsed posteriorly, often associated with posterior ligamentous injury
Extension teardrop avulsion fracture
Characterized by small fleck of bone is avulsed of anterior endplate
Indications for halo orthosis in adults
Occipital condyle fracture Occipitocervical dislocation Stable type II atlas fracture (Stable Jefferson) Type II odontoid fractures Type II and IIA hangman's fractures
Contraindications for halo orthosis
Cranial fractures
Infection
Severe soft-tissue injury
Characteristics of osteoporotic bone
Bone is normal in quality but decreased in quantity
Cortices are thinned
Cancellous bone has decreased trabecular continuity
Components of the anterior column of the spine
ALL, anterior 2/3rds of vertebral body and annulus
Components of the middle column of the spine
PLL, posterior 1/3rd of vertebral body and annulus
Components of the posterior column of the spine
Pedicles, lamina, facets, ligamentum flavum, spinous process, posterior ligament complex
Components of posterior ligamentous complex
Supraspinous ligament, interspinous ligament, ligamentum flavum, facet capsule
Definition of cervical spondylosis
Chronic disc degeneration and associated facet arthropathy that can lead to radiculopathy, myelopathy, and discogenic neck pain
Causes of cervical myelopathy
Degenerative cervical sponylosis, congenital stenosis, OPLL, tumor, epidural abscess, trauma, cervical kyphosis
Presentation of myleopathy
Neck pain and stiffness, extremity paresthesias, weakness and clumsiness, gait instability, urinary retention
PE signs for myelopathy
UMN signs, weakness, decreased proprioception and pain sensations, positive Lhermitte sign
Cord compression occurs when canal diameter is…
Less than 13 mm in diameter
MRI findings of cord compression
Effacement of CSF, bright signal of T2 (myelomalacia)
Definition of cervical radiculopathy
Clinical syndrome caused by nerve root compression in the cervical spine characterized by sensory or motor symptoms in the upper extremity
Symptoms of cervical radiculopathy
Neck pain, unilateral arm pain, unilateral dermatomal numbness and tingling, unilateral weakness
PE findings of C5 radiculopathy
Deltoid and biceps weakness
Diminished biceps reflex
PE findings of C6 radiculopathy
Brachioradialis and wrist extension weakness
Diminished brachioradialis reflex
Paresthesias in thumb
PE findings of C7 radiculopathy
Triceps and wrist extension weakness
Diminished triceps reflex
Paresthesia in the index, middle, and ring fingers
PE findings of C8 radiculopathy
Weakness to distal phalanx flexion of middle and index finger
Paresthesias in the little finger
Absolute cervical stenosis
Defined as canal diameter
Relative cervical stenosis
Defined as canal diameter of 10-13 mm
Differential for benign extradural tumors
Hemangioma, enchondroma/chondroma, osteochondroma, osteoma/osteoblastoma
Differential for malignant extradural tumors
Osteosarcoma, chondrosarcoma, chordoma, Ewing sarcoma, giant cell, plasmacytoma, multiple myeloma
Differential for intradural, extramedullary tumors
Meningioma, Schwannoma, neurofibroma, filum terminale ependymoma
Differential for intradural, intramedullary tumors
Astrocytoma, ependymoma, hemangioblastoma
Most common location of spinal hemangiomas
Vertebral bodies of thoracic and lumbar regions
Characteristic imaging of spinal hemangiomas
Honeycomb appearance
Management of spinal hemangiomas
Pre-operative angiography is used to visualize the tumor blush, and endovascular embolization should precede surgical resection to minimize blood loss in most cases
Most common locations in osteomas/osteoblastomas
Mostly in the lumbar spine but can also be found in the cervical, thoracic, and sacral regions
Difference between osteomas and osteoblastomas
Histologically identical
Osteoblastomas are larger than 2.0 cm
Management of osteomas and osteoblastomas
Resection via curretage and possible grafting
Incomplete resection is associated with a high rate of recurrence therefore radiation therapy can be used as adjuvant therapy
Most common location of spinal chordomas
Cranially at the clivus or caudally at the sacrococcygeal region
Plain x-ray characteristics of giant cell tumors
“Soap bubble” in the vertebra
Important association of giant cell tumors
Pulmonary mets
Common location for spinal meningiomas
At the foramen magnum, attached to the ventral rim
Common presentation of spinal neurofibromas
Commonly associated with nerve roots and patients tend to present with weakness and radiculopathy
Common presentations of intradural, intramedullary tumors
Myelopathy or radiculopathy
Treatment of type 1 and 3 odontoid fractures
External immobilization
Factors that support the use of surgical stabilization and fusion in type 2 odontoid fractures
Dens displacement 5 mm or more
Comminuted fracture (IIA)
Patient > 50 years old
> 6 months before injury and treatment
Failed alignment with external immobilization
Non-surgical treatment of jumped facets
Gardner-Wells tongs - serially increasing traction weight to reduce dislocation has been shown to be safe in patients who are awake and able to cooperate with an exam
Formula for determining the maximum weight during cervical traction
P = 3 to 4 kg (weight of head) + 2 kg per vertebral level away from the cranium
Major complication associated with jumped facets
Vertebral artery injury resulting in Wallenberg’s syndrome
Symptoms of Wallenberg’s syndrome
1) ipsilateral loss of pain/temp in the face, limbs, and trunk
2) nystagmus
3) tinnitus
4) diplopia
5) contralateral loss of pain/temp throughout the body
6) ipsilateral Horner’s syndrome
7) dysphagia
8) ataxia
Physical exam findings of patients with degenerative cervical disc disease
More pain with neck extension than flexion
Pain with flexion is muscle or disc related; pain with extension is facet or foramen related
Spurling’s sign
Extension and rotation toward the symptomatic side reproduces the radicular symptoms
Pathologic reflexes in cervical spondylotic myelopathy
Finger escape sign, grip and release test, Hoffman’s, inverted radial reflex
Finger escape sign for cervical myelopathy
Patient holds fingers extended and adducted
In patients with cervical myelopathy, the two ulnar digits will flex and abduct, usually in less than 1 minute
Grip and release test
Normally, a patient can make a fist and rapidly release it 20 times in 10 seconds
Patients with myelopathy are unable to do this that quickly
Inverted radial reflex
Tapping the distal brachioradialis tendon produces hyperactive finger flexion
Scapulohumeral reflex seen in patients with high cord compression
Tapping the tip of the spine of the scapula elicits a brisk scapular elevation and abduction of the humerus if there is high cord compression
Pavlov’s ratio for measuring spinal stenosis
Sagittal canal diameter divided by sagittal diameter of vertebral body
A ratio of 0.8 or less defines a congenitally narrow spinal canal, which puts the patient at higher risk for cord compression
Measurement on a lateral plan radiograph that indicates cord compression
In patients with spondylosis, a spinal canal measurement on a lateral plain radiograph of 12 mm or less often indicates cord compression
Determining cervical instability on flexion/extension views
Flexion and extension views show > 3.5 mm and/or translation > 11 degrees of angulation
Radiographic findings in the cervical region that warrant earlier operative intervention
Smaller cord area, cord atrophy, signal changes indicative of myelomalacia, or the presence of a kyphotic deformity
Definition of cranial settling
Superior migration of the odontoid leading to brainstem compression
McGregor’s line used to determine cranial settling
Line drawn on the lateral view from the hard palate to the base of the occiput
Vertical settling of the occiput has been defined as migration of the odontoid > 4.5 mm above McGregor’s line
Definition and significance of the high-intensity zone on MRI
The HIZ is identified as a small, round lesion that shows a bright signal along the posterior-inferior annulus on T2WI
These lesions are associated with an annular tear in more than 90% of cases with discography
Type I Hangman fracture (Levine classification).
< 3 m subluxation of C2 on C3 and NO angulation.
Type Ia Hangman fracture (Levine classification).
Anterior C2 VB may be subluxed 2-3 mm anteriorly on C3 and the C2 VB may appear elongated.
Type II Hangman fracture (Levine classification).
Subluxation of C2 on C3 > 3mm and/or angulation.
Type IIa Hangman fracture (Levine classification).
Little subluxation (usually < 3mm) but more angulation (can be > 15 degrees).
Type III Hangman fracture (Levine classification).
Type II with bilateral C2-3 facet capsule disruption.
C2 posterior arch is free floating.
Surgical indications for Hangman’s fractures.
- Inability to reduce the fracture (includes most Levine type III and some type II).
- Failure of external immobilization to prevent movement at fracture site.
- Traumatic C2-3 disc herniation with compromise of the spinal cord.
- Established non-union.
Type 1 Modic endplate change.
- T1 low, T2 high.
2. Associated with pain and instability.
Type 2 Modic endplate change.
- T1 high, T2 normal.
- Presence of yellow marrow accounts for shortening of T1 signal.
- More common than type 1.
Type 3 Modic endplate change.
- T1 low, T2 low.
2. Less segmental instability secondary to advanced degeneration and sclerosis.
Description of Klippel-Feil syndrome.
- Multiple fused cervical vertebrae due to failure of segmentation.
Description of Type 1 Klippel-Feil syndrome.
- Fusion of many cervical and upper thoracic vertebrae.
2. High risk of scoliosis (30%).
Description of Type 2 Klippel-Feil syndrome.
- Fusion at one or two interspaces combined with other congenital spinal abnormalities.
Description of Type 3 Klippel-Feil syndrome.
- Fused cervical vertebrae with thoracic or lumbar fused vertebrae.
Description of Type 1 split cord malformation.
- Characterized by two hemicords, each within its own dural tube, separated by a bony/cartilaginous septum.
Description of Type 2 split cord malformation.
- Characterized by two hemicords in a single dural tube, separated by a fibrous septum.
Power’s ratio.
- Ratio of distance from basion to C1 lamina divided by distance from opisthion to anterior ring of C1.
- Identifies anterior subluxation if ratio > 1.
Harris’s rule of 12.
- A basion-axial interval or basion-dental interval > 12 is indicative of an atlantooccipital dissociation.
Condyle-C1 interval.
- Distance between the occipital condyle and the C1 lateral mass on sagittal imaging.
- A value greater than 2.5mm is consistent with dissociation.
Dickman type 1 classification of transverse alar ligament injuries.
- Midsubstance disruption of TAL.
2. Ligament will not heal.
Dickman type 2 classification of transverse alar ligament injuries.
- Avulsion of the tubercle with TAL attached.
2. Bony injury that may heal.
Rule of Spence.
- Greater than 7mm composite overhang is indicative of a TAL injury.
Type 1 axis fracture.
- Minimal displacement (<3mm).
Type 2 axis fracture.
- Significant displacement (>3mm) and angulation > 11 degrees.
Type 2a axis fracture.
- Minimal displacement (< 3mm) but angulation > 11 degrees.
Type 3 axis fracture.
- Associated with facet dislocation.
