Advanced Diagnostics: Week 4
Radiographic Views of Wedge Compression Fracture
-AP view: buckling of lateral cortices, decreased body height -lateral view: decrease anterior body height, posterior body height maintained
Common sites of spinal fractures
-C1-2, C5-7, T9-L
Schmoral nodes
-defects in the IV end plate
What are non-simple MVA examples (c-spine rules)?
-pushed into oncoming traffic -hit by bus or large truck -rollover -hit by high speed vehicle
Diagnostic Rule for Vertebral Fracture
Criteria: -female -age > 70 yrs -trauma (major trauma in younger pts, minor in older adults) -long term use of corticosteroids *spec 100% and sens 38% with > or = to 3 criteria met
T or F: MRI is highly sensitive and specific for detecting infection and malignancies causing back pain.
True
MRI findings for Myelomalacia
cord damage -small areas of high intensity signal in spinal cord, cord bleeding -highly indicative of poor recovery
Fatty infiltrate into the lumbar multifidus and other paraspinal muscles are prognostic for...
development and persistence of LBP
_____________________: bilateral fx through the pedicles of C2 with anterior dislocation/subluxation of the C2 body over C3; caused by a hyperextension and distraction injury (i.e. hanging, hyperextension more common like a face striking a windshield); often w/ spinal cord compromise/tearing
hangman's fx
What is the first line of study for patients with chronic neck pain w/ or w/o a hx of previous trauma
x ray
Radiographic Views of Thoracic Spine
AP lateral *difficult to view due to shoulders
Radiograph Views of the Cervical Spine
Routine Views: -lateral view -AP Special Views: -oblique view -odontoid view -swimmer's view
Classification of Odontoid Process fractures
Type 1: STABLE, fx of upper part of odontoid Type 2: UNSTABLE, transverse fx through the odontoid base Type 3: STABLE, fx through odontoid base and extending into body of axis
Classification of Hangman's Fracture
Type 1: fx through C2 pedicle, extend btw sup and inf facets Type 2: type 1 fx with concomitant disruption of C2-3 IVD Type 3: type 2 with C2-3 dislocation (usually anterior)
Radiographic Signs of Cervical Spondylosis
anterior lipping of vertebral bodies closure of foramen posterior osteophytes
_______________________: failure of anterior and middle columns due to axial compression forces
compression burst fracture *CT and MRI are essential
Radiographic Views of Compression Burst Fracture
-AP view: vertical laminar fx, decrease distance btw pedicles, splaying of posterior facet joints -Lateral view: decreased ant and post body height, comminution of vertebral body, fragments may be retropulsed into spinal canal
3 columns of the Thoracolumbar Spine
-Anterior: ant 2/3 vertebral bodies and disc, ALL, usually stable if fx occurs here -Middle: post 1/3 vertebral bodies and disc, PLL, potentially unstable fx -Posterior: posterior arch, facet joint and capsule, post ligament complex and Lig Flavum; unstable fx
Degenerative changes of the C-Spine
-C4-7 are common areas in which these changes occur (appear by age 30-40) -radiograph findings: decreased disc space, sclerosis, spurring of the margins of the vertebral bodies -narrowing of foramina may play a part in arm pain -MRI indicated for evaluation of suspected herniated disc or neurological deficit
AP view of Cervical Spine: Patient Position, Structures Shown, Conditions Demonstrated
-Patient Position: standing or supine, chin slightly extended, central ray centered on C4 and angled 15-20 deg cephalad -Structures: shows lower 5 cervical vertebrae, upper 2 thoracic vertebral bodies, interpediculate spaces, IV disc spaces, superimposed transverse processes and articular pillars/processes, spinous processes -Conditions Demonstrated: fractures (bodies of C3-7), IVD space abnormalities, uncovertebral joint abnormalities, shows alignment and oblique fxs
Odontoid view of Cervical Spine: Patient Position, Structures Shown, Conditions Demonstrated
-Patient Position: supine, mouth opened as wide as possible -Structures: atlas and axis, C1-2 interspace, dens of C2, lateral mass of atlas, spinous process of axis, mandibular ramus occipital base, teeth occlusions -Conditions Demonstrated: fx of lateral masses of C1, odontoid process, vertebral body off C2 and Jefferson fx; atlantoaxial joint abnormalities
AP view of Thoracic Spine: Position, Structures, Conditions Demonstrated
-Position: patient supine or upright, hips and knees flexed in supine to reduce kyphosis -Structures: thoracic vertebral bodies, IVD spaces, transverse processes, costovertebral joints -Conditions Demonstrated: fractures (body, end plate, pedicles, transverse processes), fracture-dislocations, IVD space abnormalities
Lateral view of Lumbar Spine: Position, Structures, Conditions Demonstrated
-Position: pt sidelying on affected side, hips and knees slightly flexed w/ pad support, pad support under lower thorax to keep spine horizontal -Structures: lumbar vertebral bodies and interspaces, spinous processes, pedicles, lumbosacral junction, profile of IV foramen (except L5-S1) -Conditions Demonstrated: fx (vertebral bodies, end plates, pedicles, spinous processes, Chance fx), fx-dislocations, IVD space abnormalities, IV foramina abnormalities, Schmorl nodes, Spondylolisthesis (spinous process or step-off sign)
AP view of Lumbar Spine: Position, Structures, Conditions Demonstrated
-Position: pt supine, knees flexed to reduce lordosis and improve visualization of disc spaces -Structures: lumbar vertebral bodies, IVD spaces, laminae, spinous processes, transverse processes -Conditions Demonstrated: fractures (vertebral bodies, end plates, pedicles, transverse processes), fx-dislocations, IVD space abnormalities, spondylolisthesis (inverted Napoleon's Hat sign)
Lateral L5-S1 Projection: Position, Structures
-Position: same as lateral lumbar -Structures: high quality look of joints btw L4/5, L5/S1 (lumbosacral junction), lower one or two Lumbar vertebrae and upper sacrum
Lateral view of Thoracic Spine: Position, Structures, Conditions Demonstrated
-Position: side-lying on affected side, hips and knees slightly flexed (pad support-under lower thorax to keep spine horizontal) -Structures: thoracic vertebral bodies and interspaces, intervertebral foramina, spinous processes (ribs superimposed) -Conditions Demonstrated: fractures (body, end plates, pedicles, spinous processes, Chance fx), fx-dislocations, IVD space abnormalities, IV foramina abnormalities, Schmorl nodes
Oblique L-Spine View: Position, Structures, Conditions Demonstrated
-Positions: pt lying 45-60 deg oblique angle with affected side down (places the zygopophysial jts on affected side into the plane of the central ray) -Structures: lumbar vertebral bodies and interspaces, articular processes on side closest to table, ZPJ on side closest to table, "Scottie dog", neural foramen -Conditions Demonstrated: articular process/facet abnormalities, pars interarticularis abnormalities, scottie dog configuration, Spondylosis
What is the Cobb angle?
-The way to measure the curvature of the spine in degrees, and the number of degrees helps the decide what treatment is necessary -upper margin of vertebral body on sup aspect of curve and lower aspect of vertebral body on inf aspect of the curve = angle measured
What is the "owl" in the thoracic spine?
-a good indication of health of vertebral bodies -the eyes are the pedicles, head is the body, nose is the spinous process and ears are the transverse processes -in metastatic lesions w/ bony destruction: will see "winking owl's sign" where there is only one owl eye apparent; highly SPECIFIC finding of metastatic CA in T-spine in an AP view (CA selectively attacks pedicle and will cause ant and post body fx)
What is the Scottie Dog sign?
-any cracks to neck of dog (pars interarticularis) or posterior translation of body/tail -superior articular process: ear -transverse process: nose -pedicle: eye -lamina: body -inferior articular process: foot -pars articularis: neck
MRI findings of disk pathology
-as disk gets older, looks darker and thinner on MRI: decreased T2 signal bc of decreased hydration/proteoglycan content and increased collagen/fibrosis -small specks of brightness in disc: annular tears that look like focal increases on T2 (hotspots) -nuclear herniation through annular tears= focal disk contour abnormalities -nuclear clefts normally look dark, but may fill with fluid when supine or flexed -> increase T2 signal -calcified disk: increase T1 w/ small amts, decrease in T1/T2 with more calcification
Spinal Fractures and Columns Involved
-compression fracture: anterior column compressed, middle and posterior column uninvolved -burst: ant and mid column compressed, posterior column uninvolved or distracted -seat-belt (Chance): ant column uninvolved or compressed, middle and posterior columns distracted -fracture-dislocation: compression and/or rotation, shear in ant column; distraction and/or rotation, shear in middle and post columns
Vertebral body abnormalities
-congenital: hemivertebra -fractures -Scheuermann's disease: AVN or steroid use, involves both inf and sup end plates, increase in thoracic kyphosis
What is the Canadian C spine rule?
-developed for radiographs of the c-spine following ACUTE trauma -decision rule for detection of clinically important injury: rule IN need for x ray after trauma -if negative, almost certain no cervical fx; if positive, doesn't mean there is a fx but imaging is indicated -very sensitive and specific
Disc Nomenclature: Protrusion, Extrusion and Sequestration
-diffuse bulge: >50% circumference -broad-based protrusion: 25-50% circumference -focal protrusion: <25% circumference, A > B, overall disc height (A) still higher than protrusion height (B) -extrusion: B> A -sequestration: separation
Radiographic Signs of Instability
-displacement of vertebrae -widening of interspinous or interlaminar spaces -widening of facet joints -widening and elongation of the vertebral canal (widening interpedicular distances) -disruption of PLL
Oblique view of Cervical Spine: Patient Position, Structures Shown, Conditions Demonstrated
-done only after fx or dislocations are ruled out -Patient position; upright or supine with body/head angled at 45 deg from plate, chin slightly elevated -Structures: NEURAL FORAMEN and pedicles farthest from film (closest to ray), vertebral bodies -Conditions Demonstrated: intervertebral (neural) foramina abnormalities/narrowing, apophysial joint abnormalities (spondylosis, spondylolisthesis)
What are dangerous mechanisms of injury(c-spine rules)?
-fall from > or = 1 m or 5 stairs -axial load to head (i.e. diving) -high speed MVA (> 60 mph), ejection, rollover -involving motorized recreational vehicles -bicycle collision
What are the fractures of the c-spine that can be seen with the lateral view?
-fx of ant and post arches of C1 -odontoid process -vertebral bodies of C2-7 -spinous processes -Hangman's fx -burst fx -Teardrop fx -Clay-shoveler's fx -compression fx
5 findings that predict cervical myelopathy with the greatest accuracy
-gait deviation -Hoffman's reflex -Inverted supinator sign -Babinski reflex/up-going plantar response -age > 45 years *3 of 5 + is 99% specific, 4/5 if positive diagnosis
Indications for Operative tx of Idiopathic Scoliosis
-increasing curve in growing child -severe deformity (> 50 deg) with asymmetry of trunk in adolescent -pain uncontrolled by nonoperative tx -thoracic lordosis -significant cosmetic deformity *last line of defense!
Indication for a bone scan
-initial staging of lung, breast or prostate CA -bone pain -elevated alkaline phosphatate -to evaluate the response to chemotherapy
Metastatic Lesion: Cervical Spine
-low signal intensity relative to marrow signal -presented with rapidly worsening weakness of arms and legs (at C3) -radiographs: > 70-80% of bony destruction has to occur before it shows up on x ray
Prevertebral Soft Tissue/Space Lines on Radiographs
-measure the soft tissue in front the vertebral bodies and behind the air shadow of the pharynx, larynx and trachea -from C2-4: distance should not be > 7 mm in neutral (retro-pharyngeal) -From C5-7: distance not > 20 mm (retro-tracheal) -any soft tissue mass, post-traumatic hematoma or neoplasm from adjacent structures will cause an increase
Clinical Signs of Ankylosing Spondylitis
-morning stiffness > 30 min duration -improves with exercise and activity, not better with rest -waking bc of LBP during 2nd half of night -alternating buttock pain -pain duration > or = 3 mos. Increased suspicious if: -younger age (<45, usu age 25-32), family hx of SpA, hx of psoriasis, uveitis, dactylitis, ant chest wall pain, enthesitis (esp heel pain), good response to NSAIDs, Crohn's dz
Spinal Neoplasms
-most common neoplasm in the spine is metastatic dz from CA somewhere else in the body -lesions may be lytic or sclerotic (lucent or osteopaque) -lytic lesions: most likely metastasize in spine (lung, kidney, breast, thyroid, colon, multiple myeloma) -sclerotic lesions: prostate CA (men), breast, uterine and ovarian CA (women) -arise in the red marrow, best study is BONE SCAN
MRI vs Radiographs in patients with LBP
-nearly identical outcomes -pts and physicians preferred MRI over radiographs, but it had little or no additional benefit -increased costs with use of MRI -more likely to have sx with MRI group (3x as likely) -high false + rates: abnormal findings in asymptomatic pts
Indications of Cervical subluxation
-neck pain, feeling of head falling forward w/ flexion -occipital headaches, ear and facial pain -weakness, loss of endurance, loss of dexterity -parasthesias, ataxia, tinnitus, vertigo, visual disturbances, dysphagia Physical Exam -Lhermitte's sign -Modified Sharp-Purser test -tone changes -gait disturbances -UMN sxs
Thoracic Kyphosis Angle
-on a lateral film draw a line parallel to the sup. end plate of T1 and another line parallel to the inf. end plate of T12 -draw right angle to these lines until they intersect -this angle increases with age -normal ranges: 7-40 deg (young adult male), 30-56 deg (older male), 13-48 deg (young adult female), 32-66 deg (older female)
What is the anterior atlantodens interval (AADI)?
-on lateral view, measure the distance btw the posterior margin of the anterior tubercle and the anterior surface of the dens -distance > 2.5 mm indicative of instability -may need to take in flex/ext bc lateral view in neutral may miss these cases of instability (ext reduces subluxation) -causes: trauma, Down's syndrome, AS, RA, psoriatic arthritis, Reiter syndrome
What is the George Line?
-posterior spinal line, connects posterior vertebral bodies -should look like a smooth curve on radiographs -Flex/Ext views may be useful in appreciating disruption -anterolisthesis or retrolisthesis may be evidence of instability due to fx, dislocation, ligamentous laxity, DJD
Radiographic Findings of Whiplash Injury
-results in sprain or intervertebral disc injury w/o fracture or dislocation -typical radiographic appearance is straightening (loss of cervical lordosis) of cervical spine due to muscle spasm, with the normal curvature reduced or reversed *in MRI, see fatty infiltration of cervical muscles (multifidus)
CT and MRI Advanced Imaging of Lumbar Spine Indications
-sciatica or sxs of spinal stenosis not improved in 6 wks -equally accurate for diagnosing herniated discs or spinal stenosis -done immediately in pts with sxs of cauda equina syndrome
Radiographic sign of Cervical Myelopathy
-spinal canal is normally 17-18mm across -when < 12-14, considered to be myelopathic - < 10 mm considered diagnostic for cervical myelopathy *MRI indicated for sudden onset or slowly progressive
Common Degenerative changes in the Thoracic Spine
-spurs (hypertrophic osteophytes): usually of no clinical significance -calcification of the anterior spinal ligament (diffuse idiopathic skeletal hyperostosis-DISH): due to excessive bone formation at skeletal sites subject to normal or abnormal stresses, generally where tendons and ligaments attach to bone -calcification of an IVD-usually seen in mid-thoracic region-a single disk is usually the result of trauma but multiple disk involvement may be due to hypercalcemia or other causes
Ankylosing Spondylitis: radiographic signs
-squaring of vertebral bodies -thin syndesmophytes -preservation of disc space -fusion of apophyseal joints -ossification of paravertebral ligaments -"bamboo" spine
Imaging for Chronic LBP
-sxs persist beyond 4-6 mos of conservative intervention--> get imaging -AP and lateral plain X-ray -oblique view not recommended due to increased radiation exposure, but warranted in cases that suggest spondylolisthesis and spondylolysis -bone scan can detect physiologic reactions to suspected spinal tumor, infection or occult fx
Spinal Infections
-usually occur in DM or post-op pts and IV drug abusers -appears as a destructive process that involves or crosses a disk space (tumor does NOT involve disk space): loss of disc height, endplate sclerosis, loss of defined borders -MRI preferred over CT: indicated if localized pain, elevated ESR, fever, elevated WBCs or + blood culture
Trauma to the thoracic spine
-usually the result of a MVA or osteoporosis -the AP view should be evaluated for alignment and the lateral view evaluated for subluxation/antero or retrolisthesis -hyperflexion injuries can result in compression burst fx with bony fragments projecting into the spinal canal -compression fx of the middle and lower t-spine are common due to osteoporosis or a fall
Adolescent Idiopathic Scoliosis
-very prevalent, most require no tx (fewer than 10% of children with curves of > or = 10 deg require tx) -common radiographic finding that is most likely meaningless -when angle gets to ~30 deg, start to see impairments in CV and pulmonary performance
What are the most common fractures of the lumbar spine?
-wedge compression fx of ant column -compression burst fx with fragments that are retropulsed (ant and mid columns implicated) -fx of the pars interarticularis (spondylolysis) which if bilateral may cause a subluxation of the vertebral body (spondylolisthesis)-> post columns
Lumbar Degenerative Disc Disease on MRI
-younger discs have higher signal intensity of nucleus pulposus -Grade 1: if appears homogenous and bright white -Grade 2: if inhomogenous white, horizontal bands, stage 1 of DDD -Grade 3: lose clear distinction btw annulus and nucleus: grade 3 -Grade 4: no collapsed disc space -Grade 5: collapsed disc space
Radiographic Views of Lumbar Spine
AP Lateral Oblique L5-S1 spot
___________________: flexion distraction injury (L1-2), also called a seat belt fx (occurs in rear seat passengers that don't have shoulder belts, just lap belts); horizontal fx with splitting of the spinous processes, lamina, pedicles and vertebral body (shearing force across entire spinal segment)
Chance fx *CT more SENSITIVE than xray **50% have associated blunt trauma injuries (i.e. bowel, pancreas, kidney, liver)
_____________________: fx of the spinous process of C6, C7, T1 or T2; described as an acute powerful flexion injury or an injury due to a direct blow or indirect trauma from MVA; stable fx as posterior ligaments remain intact
Clay-shoveler's fx
T or F: Plain x rays are recommended for routine evaluation of acute LBP within the first month of symptoms.
False x rays only indicated for the following red flags: -recent significant trauma (any age) -recent mild trauma (age 50+) -patient > 70 -hx of prolonged steroid use or osteoporosis
Suggestions for Imaging in Patients with Acute LBP
Immediate Imaging: -Radiographs: if risk factors for CA (new LBP w/ prior hx of cancer, etc.), significant trauma to lumbar spine, chronic LBP that didn't respond to conservative tx within 6 wks -MRI: spinal infection, and cauda equina syndrome are present; severe neurological deficits require imaging Defer Imaging after a trial of therapy: -Radiographs: weak risk factors for CA (unexplained weight loss or > 50), risk factors for or signs of ankylosing spondylitis, risk factors for vertebral compression fx (hx of osteoporosis, use of corticosteroids, older age, significant trauma) -MRI: signs and sxs of radiculopathy in pts who are candidates for sx or epidural steroid injection NO imaging required: -don't meet requirements of immediate imaging and back pain improved or resolved after 1 mo of trial therapy; previous spinal imaging with no change in clinical status
_____________________: burst fracture of C1; due to blow to vertex of head; axial load transmitted through cranium and occipital condyles into atlas and drives lateral masses of atlas outwards; results in bilateral, symmetrical fractures of the anterior and posterior arches of C1 and disruption of the transverse ligaments
Jefferson's Fracture
Cause of odontoid process fx: Older vs younger patients
Older: low energy falls (don't seem traumatic at the time), due to cervical stiffness and osteoporotic changes Younger: high impact injury
What are the stress views of the lateral c-spine projections?
hyperflexion or hyperextension -not attempted until fx ruled out -performed to demonstrate normal movement (or lack of ) due to trauma or disease -less diagnostic if pt can't get into 60 deg of F/Ext
Lateral view of Cervical Spine: Patient Position, Structures Shown, Conditions Demonstrated
initial/standard view (can evaluate alignment, spacing, soft tissues and vertebrae) -Patient Positioning: sitting or standing, shoulders depressed (hold weight), chin slightly elevated, central ray centered on C4 -Structures: cervical vertebral bodies and interspaces, articular pillars, lower 5 facet joints, spinous processes, C7-T2 may be visualized with enough shoulder depression -Conditions Demonstrated: occipito-cervical dislocation, Fractures, unilateral and bilateral locked facets, IVD space and atalanto-odontoid space abnormalities
Spinous process sign or Step-off deformity
loss of alignment of post and ant elements within columns
_____________________: fx of the odontoid process of C2 due to a hyperflexion injury; odontoid process displaced anteriorly with associated forward subluxation of C1 or C2; classification of fx based on stability
odontoid process fx
Functional Measures of Cord Compression
predictors of increased compression -6 m walking time usual and max pace -shorter step length at usual and max pace (ataxia) -chair to stand time (5 reps) -one leg standing time, step test
_________________: an age related disorder in which the density of bone mass is reduced leading to an increased risk of fx; caused by aging and estrogen deficiency, changes in Ca++
primary osteoporosis
What kinds of pain can symptomatic discs present as?
pulmonary, gastric, GI, GU, groin, testicular, cardiac or UE pain -most common sxs is pain, second most common sxs of disc pathology is neuro deficit -MRI best imaging modality
Alignment of cervical vertebrae: 4 lines
red: ALL brown: PLL green: posterior spinal canal/spino-laminal line blue: spinous processes
An AP view with rotation to left demonstrates __________ sided neuro-foramina.
right
___________________: reduction in bone density due to hyperparathyroidism, excess glucocorticoids, malabsorption of Ca++, multiple myeloma, etc.
secondary osteoporosis
Inverted Napoleon hat sign
severe anterolisthesis of the L5 and S1 seen on frontal view
________________: fx of the pars interarticularis that is less stable and w/ translation of columns anterior or posterior; slippage
spondylolisthesis
__________________: fx of the pars interarticularis without separation, stable
spondylolysis
_____________________: posterior displacement of the involved vertebrae into the spinal canal, fracture of posterior elements and disruption of soft tissues (ALL, PLL, etc.); as ALL tears, it avulses from the anterior vertebral body (leaves a small triangular teardrop shaped fragment) and displaces anteriorly and inferiorly; most severe and most unstable cervical injury
teardrop fx
Swimmer's view of Cervical Spine: Patient Position, Structures Shown, Conditions Demonstrated
used when shoulder superimposition obscures C7 on lateral view -Patient position: arm closest to film extended overhead, pt can rest head, depress shoulder closest to ray as much as possible (maybe hold weight), ray centered on C7-T1 -Structures: cervicothoracic vertebrae between the shoulders (C7-T2) -Conditions Demonstrated: fx of C7, T1, T2
Degenerative Changes of the Lumbar Spine
very common, anatomical gray hairs -disk space narrowing -osteophytes -stenosis of neural foramina -facet narrowing and eburnation -stenosis of the spinal canal -ant lipping and sclerosis
Canadian C-Spine Rules Flow Chart
w/ suspected acute cervical trauma, CT is first, then X ray *CT is very sensitive, radiograph has better specificity
__________________: failure of anterior columns under compression forces (ant or lat flexion)
wedge compression fracture
What group of people are more prone to occurrences of spondylolysis?
weightlifters and gymnasts-> forced ext constantly
When do plain films start to show osteopenia?
when bone loss is > 30% -DEXA is the preferred method to measure bone density: results given as deviation from the mean, normal bone density is within 1 SD from the young adult mean - 1-2.5 SD below the mean = osteopenia - > 2.5 SD below the mean = osteoporosis
