2. AP Open Mouth View (Odontoid) –> to view dens (teeth obscure dens if not open wide)
3. Lateral
–>Need to include T1
–>Need to see preverterbral soft tissues
4. Bilateral Oblique
5. Flexion and Extension
-Lateral Masses
-C1/C2 Alignment
–>looking for fx, trauma
-Transverse Process (lateral)
-Spinous Processes (midline)
–> looking for bony hypertrophy (excess bone)
– (more midline than facet jts)
– allow for flexion and extension, limit lateral flexion in the cervical spine
ISSUES: degenerative changes, hypertrophic arthritis, resulting in foraminal stenosis and nerve compression.
Foraminal stenosis is the most common cause of cervical nerve root pressure.
2. Posterior vertebral line
FACETS
3. Spinolaminar line
4. Spinous processes line
SUBLUXATION or FX
*Anterolisthesis* – above level forward
*Retrololisthesis* – above level behind (measured in mm)
–>Normal in children
–>Seen in 20% of children under age 8 years
-Normal values
–>Adult: 3mm
–>Child: 5mm
Helps look for subluxation.
*1. Neural foramina* = holes (look for size/narrowing)
*2. Facet joints* (angulated)
*3. Pedicles*
Compare Neutral, Flexion, & Ext. views, measuring degrees of antero/retrolisthesis >3mm difference btn. any of those views = INSTABILITY of ligaments
-TYPE III (30%): Subdentate (through body of C2) and does not involve the dens;
-**Unstable** because atlas and occiput can move together
–> Better on CT view
1) Anterior subluxation (hyperflex. sprain)
2) Simple wedge fracture
3) Unstable wedge fracture (assoc. w/lig. injury)
4) Unilateral facet dislocation (lig. injury)
5) Bilateral facet dislocation (lig injury)
6) Flexion teardrop fracture (lig injury)
7) Anterior atlantoaxial dislocation
*FOCUS ON FACET DISLOCATIONS*
Widening d/t ligament tear
-Unilateral: <50% anterolisthesis -Bilateral: >50% anterolisthesis
*Jumped facet can be unilateral or bilateral
2) Extension teardrop fracture
3) Hyperextension w/pre-existing spondylosis (degen.)
*Fx involving both pars interarticularis of C2*
Usually anterolisthesis at C2-C3
IMAGING:
–> looking for indirect sign, change in lat. masses of C1 arch and the dens (L lat mass is further from dens)
*CT much better*
FLEXION:
1) Bilateral facet dislocation
2) Flexion teardrop fracture
3) Wedge fracture with posterior ligamentous rupture
EXTENSION:
1) Odontoid fracture type II
2) Hangman’s fracture
3) Extension teardrop fracture
VERTICAL COMPRESSION:
1) Burst fracture
Spinous process
Pedicles
Intervertebral disc spaces
Vertebral body height
Alignment
-Nose = Transverse Process
-Eye = Pedicle
-Front Leg = Inferior articular facet
-Ear = Superior articular facet
-*Neck of dog = Pars Interarticularis –> look for fx (lucency) here!*
–> young pts <30 y/o, sports/stress-related activity -*Nose* = TP, *Eye* = Pedicle, *Front Leg* = inferior articular facet, *Ear* = Superior articular facet, *Neck* = Pars Interarticularis, *Body* = lamina/SP
-Forward slippage = ANTEROLISTHESIS
-Backward slippage = RETROLISTHESIS
5 MAJOR TYPES OF SPONDYLOLISTHESIS:
1) *Dysplastic* – caused by defect in formation of part of vertebra (congenital)
2) *Isthmic* -caused by defect in pars interarticularis (spondylolysis)
3) *Degenerative* – caused by arthritic changes
4) *Traumatic* – caused by direct trauma/injury to vertebrae; usually fx of the pedicle, lamina or facet joints
5) *Pathologic* – caused by abnormal bone (eg tumor)
Spondylolysis = fx of pars interarticularis resulting in A/P slippage
Spondylisis = degenerative disease
2: 25 – 50%
3: 51 – 75%
4: 76 – 100%
5 (Spondyloptosis): >100%
(-pars defect: usually grade 2 or greater, Degenerative: usually grade 1)
*Typically secondary to stress fx from repetitive injury (MC in young adolescents, who overtrain)
2) *Axial Burst Fracture*: Vertebra loses height along both anteriorly & posteriorly.
*Unstable*
3) *Chance Fracture*
Compression fracture along *anterior or lateral vertebral body* secondary to hyperflexion and compression
*Most common within thoracic spine*
*Common in osteoperotic patients*
-anterior wedge >50%
-severe hyperkyphosis
-bone fragments suspected within spinal canal
Secondary to violent forward flexion -> leads to distraction of posterior elements
–> CLASSIC “SEAT BELT INJURY”
*Common at thoracolumbar junction (T12-L2)*
*Leads to concavity and erosion of bone.*
-Can be inferior, superior or both
*Relatively common especially with increasing age*
-most are vertical (unless it’s a severe MVA/crush injury –> fragmentation)
*1. Fractures (including Pars Defects)*
*2. Pre-op & Post-op Spinal Surgery*
– bony anatomy prior to surgery
– surgical hardware alignment & integrity
*3. Characterization of osseous lesion(s)*
– neoplasm/metastases, hemangioma etc.
*4. Unable to get MRI*
– Pacemaker, retained metal fragments, etc
–> Uses *ionizing radiation*
-Multislice axial imaging performed parallel to the disc spaces.
-white: bone
-gray: fat, muscles, vessels
-black: air
– bone & soft tissue windows (L/R)
Middle: *more lateral, start to see defect*
R: lateral fx
– *pars interarticularis: horizontally oriented defect/lucency*
(facet jts: obliquely oriented defect/lucency)
*spinal canal more flute-like/champagne shape (instead of round) –> widening due to ant. slippage* (usually accompanies pars defect)
looking for:
1) retropulsion of bone (bone fragment extending back into spinal canal)
2) canal stenosis (esp. in thoracic)
–> MRI imaging
-Around level of conus – might use MRI
Usually asymptomatic – still room in canal
– more loss of vert. height
– retropulsion: causing more SC stenosis? Pt may have more Sx’s
2) Direct acute trauma in healthy vertebra
3) Neoplasms
– Infiltrative neoplasms
(eg multiple myeloma, lymphoma)
– Metastatic neoplams
(eg prostate, breast, lung)
– Primary bone neoplasm
(hemangiomas, giant cell tumors)
-medical management with or without methods of immobility
-medications (NSAIDS and narcotics)
2. Vertebral Augmentation –> If conservative care doesn’t work
2) Balloon-assisted Kyphoplasty
-Both involve injection of an acrylic cement under local anesthesia to control pain of vertebral fractures [moving against one another] -85-90% patients have rapid pain relief
2) Pain after conservative care
3) Fracture <12 months old [otherwise body is already building new bone] 4) Contraindications to medications or requirement for IV narcotics and hospital admission (??)
2) Cord compression (don’t make worse)
3) Fever and/or sepsis [don’t want to trap an infection!]
-Objective: treatment of pain (preventing painful motion of vertebral body fragments moving against one another); Stabilizes vertebra = prevent future fx
*DOES NOT RESTORE VERTEBRAL BODY HEIGHT*
*Acute Complications*
*Cement leak (biggest issue)
-Cement pulmonary embolism
-Bleeding/hematoma
-Infection
-Neurological deficit (transient or permanent)
*Delayed Complications*
-New fracture at other levels?
–> diminished compliance of vertebra b/c of cement places remaining vertebral bodies at higher risk for fx
Unipedicle (1 balloon) or bipedicle (2 balloons)
-Usually hospitalization
*Restores height loss*
-Bone infection such as diskitis with osteomyelitis.
1) Patient who cannot get MRI (pacemaker)
2) Patient with surgical hardware in spine which obscures visualization of spinal canal on MRI and CT scan.
-Less frequently performed due to the invasive nature of the test and associated risks.
CT – bone integrity
-Disc herniation
-Spinal stenosis and Cord compression
-Nerve Root Impingement (Radiculopathy/Sciatica)
*2) INFECTION* (Discitis/Osteomyelitis, abscesses)
*3) NEOPLASM* (Osseous Metastasis)
*4) DEMYELINATING/INFLAMMATORY* (MS lesions (cervical & thoracic))
*5) TRAUMA*
-Ligamentous rupture
-Epidural/Subdural Hematomas
*6) POSTOPERATIVE SPINE*
-Recurrent disc herniation versus Postoperative
*Contraindications*
– Aneurysm clip
-*Cardiac pacemaker*
– Orbital metallic foreign body, cochlear implant, IVC filter
NO CONTRAST: Patient with EGFR <30 (measure of kidney function) due to increased risk of Nephrogenic Sytemic Fibrosis (NSF)
-Lumbar back pain
-Radiculopathy
-Preoperative Planning
>> to see granulation tissue vs. recurrent/new disc herniation
– Metastatic Bone disease (bone and spinal cord)
– Spinal Infection (discitis/osteomyelitis, epidural abscess)
bone black, fluid bright, *accentuates bony structures*
T1 hypointense (dark),
T2 & STIR hyperintense (white)
*Fat:*
-T1 & T2 hyperintense (bright),
-STIR hypointense (dark)
*Normal Bone:*
-T1, T2 & STIR hypointense (dark)*
*Sclerotic Bone*
-T1, T2, and STIR markedly hypointense (very dark)*
– CSF, thecal sacs
STIR: fat dark (“suppressed”)
T2: fat bright
If VB is darker -? abnormal – tumor or degeneration = sclerotic changes
-Disk space will always be bright on T2 & stir (b/c most of the disc is fluid)
– contain fat & nerve roots
– Look for symmetry in each region (C, T, L)
– T1&2: bright signal (fat) surrounding dark signal (nerve root)
– STIR: vessels around nerve root (a little bright), but fat supressed –> STIR not a great view of foramina
–> looking for any encroachment/narrowing (facet arthropathy, disc herniation, etc)
– neural foramena: fat (bright) + n. roots (dark)
– exiting nerve root at disc space is from *level below* (eg at C5-C6, C6 exiting nerve roots noted; at C7-T1, C8 exiting nerve roots noted)
Thoracic & Lumbar spine:
– exiting nerve root at disc space from *level above* (eg at T1-T2, exiting nerve roots are T1)
*Cervical Spine: You have Uncovertebral Joints*
*Thoracic/Lumbar Spine: No uncovertebral joints*
*can cause LATERAL CANAL STENOSIS [AKA foramenal stenosis] when hypertrophied from osteoarthritis*
-Within foramen, the motor & sensory nerve roots merge into single Spinal Nerve (sensory and motor fibers). Termed “Exiting Nerve”
nerves hang like a “horse tail” inferior to L2 within the thecal sac
Comprised of spinal nerves L4 through S3
Happens with age and can change from one type to another.
-T1 hypointense (dark) and T2 hyperintense (bright)
-T1 hyperintense and T2 iso/mildly hyperintense (bright spots) [b/c it’s fat replacing bone marrow!]
-T1 and T2 hypointense (dark)
-Outer fibers of disc (Sharpey’s Fibers) anchor themselves into this region [what attach end-plates to discs below/above] -*Bone spurs (osteophytes) arise form this region* as a result of prolonged pulling/tugging of Sharpey’s fibers (degeneration)
-*water-rich* gelatinous center of disc
-bear axial load of body; pivot point for movt
*Annulus Fibrosus*
-more *fibrous* than nucleus, higher collagen / lower water content
-hold in place the highly pressurized nucleus
-outer lamellae = SHARPEY’S FIBERS
Cx>Lx
-Prone to osteoarthritis
-*Osseous overgrowth can results in lateral canal stenosis (neural foraminal stenosis)*
Look for hypertrophic changes in joint space
-allow for flexion and extension; limit lateral flexion
-osteophytes (bone spurs) form in response to degeneration to try to maintain stability of spine
-can lead to lateral canal (foraminal stenosis)
[L>R uncovertebral hypertrophy (should be nice kidney-bean shape), and facet hypertrophy]
-flexible
>> normally thicker when standing or leaning back and thinner when sitting or bending forward
-Thickening provides additional support when injury or aging occurs but…
-thickened ligament becomes less flexible and weaker and can encroach on spinal canal
-Pain arising from the *spinal root level*
-Sciatica (most common type of radiculopathy)
Treatment is often nonsurgical unless concurrent cauda equina symptoms present or not responding to conservative therapy
*CAUSES*
-Disc herniation
-Annular tear
-Strong and keeps pressurized nucleus pulposus from escaping outward
Annular Tears/Fissures:
-Separations between one of more of the annular lamellae
-Avulsion of fibers from the vertebral insertion
[when tear reaches last lamellae = 4] [Grade 5: chemical release, annular tears are NOT A MECHANICAL ISSUE – doesn’t actually leak out]
*Non-Contrast MRI: T2 hyperintensity along annulus*
*Contrast MRI: “lights up” granulation tissue in healing/healed annular disc tear*
*CAUSE: LAXITY*
3) Extrusion
4) Sequestration
*PLL is ALWAYS intact (contained disc herniation)*
OR
-No continuity exists between the herniated disc material and the disc space
-*PLL is disrupted (uncontained disc herniation)*
[compressing exiting nerve root]
-Can be contiguous or noncontinguous (sequestration) with disc space [attached or unattached]
-thecal sac
-Right central
-Left central
*2. Subarticular Zone*
-nerve roots
*3. Foraminal Zone*
-Zone between sagittal planes passing through medial and lateral edges of pedicle
*4. Extraforaminal Zone*
-nerve root compression
Herniation = trauma – PLL can be torn – can migrate
-*Surgical Emergency – immediate surgical consult needed*
CAUSE: Compression of multiple lumbosacral nerve roots below conus medullaris.
Symptoms:
-LB pain
– Sciatica (unilateral or bilateral)
-Saddle sensory disturbances
-Bladder and bowel dysfunction
-Variable lower extremity motor and sensory loss