SPine

• clumsiness in hands
• gait imbalance

• degenerative  cervical spondylolysis
• -anterior degenerative changes (osteophytes/ discosteophyte)
• -congenital stenosis
• -OPLL
• -tumor
• -epidural abscess
• -trauma
• -cervical kyphosis

lumbar spine stenosis 20%

• 0-root symptoms or normal
• 1-signs of cord compression/ normal gait
• 2-gait difficulties but fully employed
• 3-gait difficulties prevent employment, walks unnasisted
• 4- unable to walk without assistance
• 5-wheelchair or bedbound

• class 1- pain, neurologic deficit
• class 2-subjective weakness, hyperflexia, dyssthesias
• class 3- objective  weakness, long tract signs, ambulatory
• class 4- objective weakness, long tract signs, non-ambulatory

torsional strain causes tears in outer annulus leading to herniation ofnucleus pulposis

sequestered disc herniations show the greatest degree of spontaneous reabsorption

macrophage phagocytosis is mechanism of reabsorption

90% imptove in 3 months

annuus fibrosis-type 1 collagen, water proteoglycans- trnsile strength

• nucleus pulposis- low compressibility
• -high pollysachharide count 
• -collagen 2

central- can prsent as cauda back pain

paracentral-pll weakest here ( 90-95% of cases occur here)

foraminal-affects exiting upper nerve root ( l4-l5 affects l4)

axillary- exitting and  descending nerve roots

• straight leg raise
• a tension sign for L5 and S1 nerve root
• technique
• can be done sitting or supine
• reproduces pain and paresthesia in leg at 30-70 degrees hip flexion
• sensitivity/specificity
• most important and predictive physical finding for identifying who is a good candidate for surgery
• contralateral SLR
• crossed straight leg raise is less sensitive but more specific
• Lesegue sign
• SLR aggravated by forced ankle dorsiflexion
• Bowstring sign
• SLR aggravated by compression on popliteal fossa
• Kernig test
• pain reproduced with neck flexion, hip flexion, and leg extension
• Naffziger test
• pain reproduced by coughing, which is instigated by lying patient supine and applying pressure on the neck veins
• Milgram test
• pain reproduced with straight leg elevation for 30 seconds in the supine position
• gait analysis

• failure non op
• pain over a month
• tumor
• infection
• trauma
• cauda

• leg pain chief complaint
• positive straight leg raise
• weakness correlates with imagin
• married status

• 11,000 new cases/year in US
• 34% incomplete tetraplegia
• central cord syndrome most common
• 25% complete paraplegia
• 22% complete tetraplegia
• 17% incomplete paraplegia

• decreased perfusion
• lipid peroxidation
• free radical / cytokines
• cell apoptosis

methylprednisone used to prevent secondary injury by improving perfusion, inhibiting lipid peroxidation, and decreasing the release of free radicals

• a-complete
• b-incomplete ( sensory preserved)
• c-incomplete-more than half muscle groups below 3
• d-incomplete- over half have 3+ muscle strength
• e-normal

• load 30 mg/kg over 1st hour (2 grams for 70kg man)
• drip 5.4 mg/kg/hr drip
• for 23 hours if started < 3 hrs after injury 
• for 47 hours if started 3-8 hours after injury

• atypical curve pattern (left thoracic curve, short angular curve, apical kyphosis) 
• rapid progression
• excessive kyphosis
• structural abnormalities
• neurologic symptoms or pain
• foot deformities
• asymmetric abdominal reflexes
• a syrinx is associated with abnormal abdominal reflexes and a curve without significant rotation

• curves with apex above T7
• Milwaukee brace (cervicothoracolumbosacral orthosis)
• extends to neck for apex above T7

• apex at T7 or below
• TLSO
• Boston-style brace (under arm)
• Charleston Bending brace is a curved night brace

• paraplegia 1/1000
• pseudoarthrosis 1-2%
• infection 1-2% - proprionibacterium for delayed
• flat back syndrom
• crankshaft - rotation due to anterior still growing
• SMA syndrome-sma and aorto suishes third part of duodenem
• - comes from l1
• -risk factor height less than 50%, weight less than 25%

• Il-1
• Il-6
• Substance P
• bradykinin
• TNF alpha
• prostaglandins

• c5- deltoid and biceps, weaker bicep reflex
• c6-brachioradilis and wrist extension weaknes, paresthesia thumb
• c7 triceps/ wrist flexion weakness, paresthiea index middle ring
• c8- weakness to istal pahalnx felsion of middle and infex finger- parasthesia little finer

spurling- extension rotation to affected side, lateral bend, vertical compression causes symptoms in ipsilateral arm

shoulder abduction test- abduct above the head relieves symptoms

• hyperreflexia
• inverted radial reflex
• hoffman sign
• sustained clonus
• babinski

• toe to heel walk
• romberh test

l'hermitte sign

lateral - pavlov ratio less than 0.8

• normal AP diameter is ~17 mm
• relative stenosis 10-13 mm
• absolute stenosis <10 mm

• The width of the canal is not, however, constant and progressively decreases as one moves down the cervical spine.
• C1: 23 mm
• C2: 20 mm
• C3-C6: 17 mm
• C7: 15 mm

• c2-c7 alignment
• - tangential lines on the posterior edge of c2 and c7 body
• local kyphosis angle
• -

bright on t2

signal changes on t1 is worse prognosis

• compression ratio <0.4 worse prognosis
• ( smallest diameter/ largest)

• aging
• stroke
• movement disorders
• vit b12 deficiency
• ALS
• MS

• single or two level disease
• fixed cerivcal kyphosis over 10 degrees
• pathology anterior ( OPLL soft discs, osteophyte

• kyphosis less than 10 degrees, over 2 levels
• ( over 13 degrees is contraindication)
• due to bowstringing

laminoplasty only open one side cant do it if over 13 degrees kyphosis

• non union 12% for single level; 30% for multiple
• c5 palsy 4.6%
• recurrent laryngeal nerve injury
• -horseness loss of voice
• - wait for 6 weeks then consult ent
• pain
• vertebral artery injury
• esophageal injury
• hardware failure
• postlaminectomy

ptosis, miosis, anyhydrosis

in longus coli muscle at c6

• acquired
• -defen/spondylotic
• -post surgical
• -traumatic
• -inflamm

• congenital
• -achondroplasia- short pedicle with medial placed facet

• central stenosis
• -less than 100mm^2 or less than 10mm on ap ct
• -caused bu disc bulge anterior and ligamentum hypertrophy

• lateral recess
• - facet joint arthropathy and osteophyte
• -overgrowth superior  articular facet

• foraminal stenosis
• -btw medial and lateral border of the pedicle
• -compressed by ventral overhang of superior facet
• -l4/l5 level get l4 compression due to vertical anatomy

• extraforaminal stenosis
• - lateral to the edge of the pedicle

kemp sign- unilateral radicular pain from foraminal stensos worse with back exension

staight leg raise ( tension)- usually negative

valsalva test- radicular pain not worsened ( opposite of herniated disc)

• a single level decompression at L4/5 would include
• resect inferior half of spinous process of L4
• resect L4 lamina to the level of the insertion of the ligamentum flavum
• resect ligamentum flavum
• medial facetectomy and lateral recess decompression
• undercutting of facets and removal of ligamentum flavum from lateral recess
• exploration and decompression of the L4/5 and L5/S1 foramen
• palpate L4 and L5 pedicle (pedicle-to-pedicle) and be sure nerve root is patent below it.

• 5% men/ 9% women
• more likelu in afican americam diabetics and women over 8 ( due to ligamentous laxity)

5x more common l4-l5 in degen ( isthmic is l5-s1)

• facet degen
• facet joint sagital orientation
• disc degen
• ligamentous laxity

• central/lateral stenosis
• -l4-l5 affect descening l5 nerve root lateral

• grade 1- < 25%
• grade 2 25-50%
• grde 3 50-75%
• grade 4 75-100%
• grade 5 spondyloptosis

• mri indications- persisten leg pain after non op
• -t2 sagital and axial images best

plain film: instability on flex-ex 4mm transalation of 10 degrees of motion

• hla-b27 aggregates with peptides into joint causing deg
• cytotoxic t cells to hlab27

• 4:1 male to female
• presents 3rd decade of ife

6th chromosome b locus

• bilateral sacroillitis
• +/- uveitis
• HLA b27 positive cells

• systemic:
• 1- acute anterior uveitis and iritis
• 2- heart disease
• 3-pulmonary fibrosis
• 4-renal amyloidosis
• 5-ascending aortic conditions ( aortitis, stenosis, regurg)
• 6-klebsiella pneumonia synovitis

• ortho manifestations
• sacroillitis
• large joint arthritis
• cervical spine fracture
• progressive kyphosis

• less than 2 cm chest expansion ( costovertrbral pain)
• schober test

• chin brow  to vertical angle- normal is 0
• hip flexion

faber test- ipsialteral sacroilliac pain

• plain film
• squaring vertebra with marginal syndesmophytes
• bamboo spine

ferguson pelvi tilt ( 10-15 degree cephald)

illiac side erosion

NSAID, cox-2 inhibitor, and TNF alpha blockin agent

• closing wedge pedicle subtracting-
• -hing ant. vertebral body
• -30-40% degree per level

• vertebrectomy
• single level opening wedge ( needs all rupture)
• multisgement opening osteotomy

• c7-t1 cervical thoracic osteotomy
• -under correct brow chin angle to 10
• c7-t1 osteotomy- vertebral artery external to transverse formane
• -c7 lateral mass and pedicle removed

Wiltse-NEwman

1- dysplastic ( maloriented hypoplastic facts, sacral deficiency, poorly developed pars)

• 2a-isthmi fatigue fx
• 2b- pars elongation
• 2c- acute fx pars
• 3-degen
• 4-traumatic
• 5-neoplastic

• hamstring tightness
• radicular pain l4
• bowel bladder syndomres

• lateral radiograph se pars defect 80%
• oblique radigraph- scotty dog sign
• 

• bone scan most sensitive
• ct pars stress reaction- shows sclerosis

pelvic incidence = pelvic tilt + sacral slope

• pelvic incidence:
• s1 middle endplate to femoral head
• s1 endplate and perpendicular
• angle between perpendicular and line to femoral head is PI
• - direct correlate to meyerding classification

• Pelvic tilt-
• s1 middle to femoral head
• middle femoral head straight up

• sacral slope
• line parallel to s1 endplate
• horizontal line
• makes sacral slope

PT for 6 month to work on pelvic tilts, ab strenghtenting and hamstring stretching

• tlo brace 6-12 weeks
• if acute pars fracture

• surgical:
• pars repair
• l5-s1 insitu posterolateral fusion
• l4-s1 posterolateral fusion +/1 alif

• loss of h2 content and conversion to fibrocartilidage
• -causes increase
• keratin sulfate to chrondroitin ratio
• lactate
• degrative enzyme activity
• density of fibroblast like cells

• injury due direct osseous compression
• -anterior spinal artery injury ( ant 2/3 supploied)

mechanism: flex and compression

• exam: lower extremit more than upper
• -loss of motor and pain and temp
• preserve proprioceptin and vibratory 

worst prognosis- 10-20% chance of recovery

pain and temp

light tough

deep touch, vibration, proprioception

• in elederly with minor extension injury
• selective destruction lateral corticospinal tract

• exam:
• weakness in hands  more pronounced than arms and leg
• burning in arm
• late presentatio nUE have LMN ( clumsy) LE UMN ( spasticity)

good prognosis- permanent clumsy hands but can walk nad have bladder control

order of recovery: legs, bladder, proximal upper extremity, hands

pentrating trauma- hemi cord

• ipsilateral
• -motor function ( lCS)
• -propriopception and vivbratory sense

• contralateral:
• -pain temp
• -spinothalamic tract cross at spinal cord level 2 below

excellent prognosis

lose proprioception

• 10-15% cerival fracture
• elderly + young dye to hyper flexion-extension

anterior- atlantoaxial instability + transverse ligamentfailure

posterior-anterior arch collides

• aappears like type 2
• remant of old fracture vs failure to fuse

• ossifiction centers 5
• -neural arch
• body
• -odontoid
• -secondry ossifiation centre ( age 3 fuses at 12)

subdental (basilar) synchondrosis is an initial cartilagenous junction between the dens and vertebral body that does not fuse until ~6 years of age

CI-C2 (atlantoaxial) articulation is a diarthrodal joint that provides 

• 50 (of 100) degrees of cervical rotation 
• 10 (of 110) degrees of flexion/extension 
• 0 (of 68) degrees of lateral bend 

• C2-3 jointparticipates in subaxial (C2-C7)
• cervical motion which provides
• 50 (of 100) degrees of rotation
• 50 (of 110) degrees of flexion/extension
• 60 (of 68) degrees of lateral bend

apex is supplied by branches of internal carotid arterybase is supplied from branches of vertebral artery

type 1- tip avulsion frcture alar ligament- get flexd ex

type 2-waist

type 3-cancellous body of c2

• 2a-nondisplaced- c collar
• 2b-dispalced fracture from anterosuperior to posteroinferior (odnointoid screw)
• 2c-anteroinfrior to posterosuperior psif

atlanto-dens-interval (ADI) > 10mm < 13mm space available for cord (SAC)

sublaminar wiring techniques (Gallie or Brooks)require postoperative halo immobilization and rarely used

• posterior C1-C2 transarticular screws construct  
• -contraindicated in patients with an aberrant vertebral artery 

• posterior C1 lateral mass screw and C2 pedicle screw construct  
• -modern screw constructs do not require postoperative halo immobilization

• ≥ 6 mm displacement (>50% nonunion rate)
• age> 50
•  fx comminution
• anangulations > 10°
• delay in treatment
• smoker

• due to foced flexion
• lamina fracture assoc with dural tear and entrapped nerve roots

• anterior column
• -ALL
• -ant. 2/3 of theb ody

• middle column
• -pll
• -posterior 1/3 of the vertebra

• posterior column
• -pedicles
• -lamina
• -facet
• -ligamentum flavum
• -spinous process
• -PLC

• injury to middle column
• -widening of interpedicular distance
• -loss of height posterior cortex vertebra
• -PLC disrupted wirth middle and anterior column involvement

• supraspinous ligament
• interspinous ligament
• ligamentum flavum
• facet capsule

conditions where PLC is clearly rupturedbony chance fracturewidening of interspinous distanceprogressive kyphosis with nonoperative treatmentfacet diastasis

Type A : both end-plates.

Type B racture of the superior end-plate

Type Cfracture of the inferior end-plate.

Type DBurst rotation. This fracture could be misdiagnosed as a fracture-dislocation. The he mechanism of this injury is a combination of axial load and rotation.

Type E-rst lateral flexion. This type of fracture differs from the lateral compression fracture in that it presents an increase of the interpediculate distance on anteroposterior roentgenogram

injury morphology

• compression-1
• burst -2
• translation-rotation-3
• distraction -4

• neuro status
• -intact-0
• nerrveroot-2
• incomplete spinal cord injury-3
• complete spinal cord-3
• cauda equina-3

• PLC
• intact - 0 point
• suspected injury or
• indeterminate - 2
• injured - 3 points

- usually treated non-operatively

4 - may be treated operatively or non-operatively

>4 - usually considered for operative management

contraindication in elderly mortality 21% in 79 and older

• 8 pounds of torque
• 2 anterior pins- 1cm anterior to lateral third eyebrow
• -away from supraorbital nerve
• -ant and medial to temporalis muscle

2 posteior opposite side of ant.

• children 70% adult 35%
• loosening 36%
• infection 20%
• discomfort 18%
• dural puncture 1%
• abduces palsy- due to traction cranial nerve 6
• - loss of lateral gaze
• supraoprbital palsy ( too medial)
• supratrochlear palsy

• 25% subluxation with unilateral
• 50% wirth bilateral

75% occur c3-c7

• flexion compression
• vertical compression
• flexion distraction
• - facet subluxation
• -unilat facet dislocation
• -bilat facet dislocation
• -complete dislocation
• extension compression
• extension distraction
• lateral flexion

weakness to wrist extension- NUMBNESS IN THUMB

• weakness to tricep and wristflexion
• numbness index and middle finger

• ing of MRI depends on severity and progression of neurologic injury
• an MRI should always be performed prior to open reduction or surgical stabilization
• if a disc herniation is present with compression on the spinal cord, then you must go anterior to perform a anterior cervical diskectomy

• diabetes
• alcohol
• valproic acid
• hyperthermia

• cardiac defects- 10%
• Genitourinary defects-25%
• spinal cord malformations
• VACTERL
• -vertebrral malformation, anal atresia, cardic malformations, tracheo-esophageal fistual, renal and radial anomolies, limb defects

• goldenhar syndrome ( hemifacial macrosomia)
• jarcho-levin syndrome- AR, thoraric insufficiency syndrome, trunk dwarfism
• klippel-feil syndrome- short neck low posterior hairlune, fusion cervical vertebrae
• alagille syndrome- peripheral pulmonic stensosis , cholestatis

• unilat unsegmented bar with contralateral hemivertebra ( 5-10 degree a year)
• unilat unsegmented bar
• fully segmented hemivertebra
• unsegmented hemi
• incarcerated hemi vertebra
• unincarcerated hemi
• block vertebra

• Chiari malformation
• tethered  cord
• syringomyelia
• diastematomyelia
• intradural lipoma

• mportant to obtain studies for associated abnormalities  
• renal ultrasound or MRI
• echocardiogram if suspicion for cardiac manifestations

atients < 6 yrs. and flexible curve < 40 degrees best candidates

• cause of radicular pain
• most often at l4-l5 level

• microinstability of the facet leading to 
• extruded synovium through joint capsules
• myxoid degeneration of collagen tissue
• proliferation of fibroblasts with increased hyaluronic acid production

• flexion distraction injury
• posteior 2/3 column fail under tension
• 50% with gi injury

non marginal syndesmophytes at three succesive levels (involving 4 contigious vertebrae)

• prevelence
• > 50 y.o. (25% males; 15% females)
• > 80 y.o. (28% males; 26% females)

ommon in the thoracic spine (right side) > cervical > lumbar

• rissk factors
• gout
• hyperlipidemia
• diabetes

• pain stifness
• dysphagia
• stridor
• hoarseness
• sleep apnea

• Heterotopic ossification
• increased risk of HO after THA
• 30-50% for THA in patients with DISH
• <20% for THA in patients without DISH

• 50-60% of cases occur in lumbar spine
• 30-40% in thoracic spine
• ~10% in cervical spine

• V drug abuse
• diabetes
• recent systemic infection (UTI, pneumonia)
• obesity
• malignancy
• immunodeficiency or immunosuppressive medications
• malnutrition (serum albumin < 3 g/dL indicative of malnutrition)
• trauma
• smoking

• -staph aureus (50-65%)
• -staph epidermidis (second most common)
• -gram negative infections
• -pseudomonas
• seen in patients with IV drug use

• salmonella
• seen in patients with sickle cell disease

• contiguous spread from local infection
• -most commonly associated with retropharyngeal and retroperitoneal abscesses

 hematogenous spread: endplates contain area of low-flow vascular anastomosis that may provide an environment suited for inoculation

• 1-paraspinous soft tissue swelling (loss of psoas shadow)
• seen if first few days

• 2-disc space narrowing and disc destruction
• seen at 7-10 days

3-endplate erosion or sclerosis seen at 10-21 days

4-local osteopenia


mri with gadolinium- gold standard ( 96% sensitive and 93% specific

• disc + endplate enhancement
• t2 weighted hyperintensity of disk and endplate

• 1-superficial and non-anatomic tenderness
• 2-pain with axial compression or simulated rotation of the spine
• 3-negative straight-leg raise with patient distraction
• 4-regional disturbances which do not follow dermatomal pattern
• 5-overreaction to physical examination

• atlantoaxial subluxation
• basilar invagination
• subaxial subluxation

due to pannus destroying transverse ligament

• flex ex xrays: anterior atlanto dens interval
• over 3.5 mm of motion is unstable
• over 7 mm disruption of alar ligament
• over 10 mm is indication for surgery

• PADI
• less than 14 mm indication for surgery
• over 13 mm most important to show complete neuro recovery

superior migration of dens

• ranawat c1-c2 index
• -c2 pedicle to line across ant and post c1 arch
• normal in men 17; women 15
• less than 13 is impaction

• mcgregor line
• -posterior edge hard palate to caudal point of occiuput
• -dens should not protrude more than 4.5mm

• chamberlain line
• -dorsal margin hard palate to foramen magnum
• - normal tip of dens to basion of occiput 4-5mm

• mcrae line
• -if dens below foramen magnum we good

• MRI:  cervicomedullary angle  suggest impending neuro impairment 
• ventral surfaces of the medulla and upper cervical cord

• subaxial subluxation (of vertebral body) of >4mm or >20% indicates cord compression
• cervical height index (body height/width) < 2.0 is almost 100% sensitive and specific for predicting neurologic compromise

begins in the metaphysis of the vertebral body

• spreads under the anterior longitudinal ligament and leads tocontiguous multilevel involvement
• skip lesion or noncontiguous segments (15%)

paraspinal abscess formation (50%)

usually anterior and can be quite large (much more common in TB than pyogenic infections) 

• chronic:
• severe kyphosis- non op 15%
• 5% get over 60 degrees

in children kyphosis can progress in 40% of patients, in adults its stable

• Type-I, increase in deformity until cessation of growth
• should be treated with surgery
• Type-II, decreasing progression with growth 
• Type-III, minimal change during either active / healed phases.

• low signal on T1-weighted images, bright signal on T2-weighted images
• presence of a septate pre-/ paravertebral / intra-osseous smooth walled abscess with a subligamentous extension and breaching of the epidural space  
• end-plate disruption 
• sensitivity 100%, specificity 81%
• paravertebral soft tissue shadow
• sensitivity 97%, specificity 85%
• high signal intensity of the disc on the T2-weighted image
• sensitivity 81%, specificity 82%
• spinal cord
• edema
• myelomalacia
• atrophy
• syringomyelia

• atypical bacteria
• -Actinomyces israelii
• -Nocardia asteroids
• -Brucella

• fungi
• -Coccidioides immitis
• -Blastomyces dermatitidis
• -Cryptococcus neoformans
• -Aspergillosis

• spirochetes
• -Treponema pallidum

• isoniazid (H), rifampin (R), ethambutol (E) and pyrazanamide (Z) therapy
• regimen

RHZE for 2 months, then RH for 9 to 18 months

• defomrity (gibbus_
• retropharyngeal abscess
• tb arteritis
• resp compromise
• sinus formation
• potts paraplegia
• -abscess bony sequestra or meningomyelitis

cervical rotational deformity away from the affected side, tilt toward the affected side


venous outflow obstruction

• ften associated with other packaging disorders
• DDH (5 - 20% association) 
• metatarsus adductus 
• traumatic delivery
• plagiocephaly (asymmetric flattening of the skull)
• congenital atlanto-occipital abnormalities

strethcing for up to 1 year

• z lengthening or bipolar release
• - reuslts good in 4-8 years

• congenital fusion of 2 or more vertebrae
• sGM1 gene (Chr 8)
• Notch and Pax genes

• ongenital scoliosis 
• Sprengel's deformity (33%) 
• renal disease (aplasia in 33%)
• deafness (30%)
• congenital heart disease / cardiovascular (5-30%)
• synkinesis (mirror motions)
• brainstem abnormalities
• congenital cervical stenosis 
• basilar invagination
• atlantoaxial instability (~50%)
• adjacent level disease (100%)

• Fusions above C3, especially those with occipitalization of the atlas are most likely to be symptomatic and require abstaining from contact sports
• Fusions below C3 are least likely to be symptomatic, and most likely to have a normal life span

• basilar invagination- above mcraes line
• atlantoaxial instability- Atlanto dens over 5mm
• degen changes
• calcifications

• basilar invagination
• chronic pain
• myelopathy
• associated atlantoaxial instability
• adjacent level disease if symptomatic

• flexible curves
• Cobb angle > 30°
• RVAD > 20°
• phase 2 rib-vertebrae relationship (rib-vertebral overlap)

• curves are more likely to progress
• (scoliosis progresses 1° to 2° per month starting at age 8 to 10 years)
• curve begins at earlier age
• curve is a long, stiff C-shaped curve
• left sided curves are not uncommon
• curve has greater sagittal plane deformity (kyphotic or lordotic)

associated with pelvic obliquity, 

• skeletal maturity is delayed in CP
• bracing is less effective
• longer fusions to the pelvis are often necessary
• patients are more medically fragile and a multi-disciplinary approach is often necessary

• A rigid thoracic hyperkyphosis defined by > 45 degrees
• caused by anterior wedging of  >5 degrees across three consecutive vertebrae
• differentiated from postural kyphosis by rigidity of curve

• orthopaedic manifestations
• hyperlordosis
• spondylolysis (30-50%)
• scoliosis (33%)
• nonorthopaedic manifestations
• possible pulmonary issues in curves exceeding 100 degrees

• anterior wedging across three consecutive vertebrae 
• disc narrowing
• endplate irregularities
• Schmorl's nodes (herniation of disc into vertebral endplate)
• scoliosis  
• compensatory hyperlordosis
• important to look for spondylolysis on lumbar films
• hyperextension lateral xrays
• can help differentiate from postural kyphosis
• Scheuermann's kyphosis usually relatively inflexible on bending xra

• ervical spine (C3-7)
• planes
• 0° coronal
• 45° sagittal (angled superio-medially) 
• function
• allows flexion-extension, lateral flexion, rotation

• thoracic spine
• planes
• 20° coronal
• 55° sagittal (facets in coronal plane) 
• 6 degrees of freedom  
• function
• allows some rotation, minimal flexion-extension (also limited by ribs)  
• prevents downward flexion on heart and lungs  
• lumbar spine
• plane
• 50° coronal
• 90° sagittal (facets in sagittal plane)  
• function
• allows flexion-extension, minimal rotation
• helps increase abdominal pressure

• Pedicle diameter
• the pedicle wall is twice as thick medially as laterally
• T4 has the narrowest pedicle diameter (on average)  
• T7 can be irregular and have a narrow diameter on the concave side in AIS
• T12 usually has larger pedicle diameter than L1
• Pedicle length
• pedicle length decreases from T1 to T4 and then increases again as you move distal in the thoracic spine
• T1: 20mm
• T4: 14mm (shortest pedicle)
• T10: 20 mm
• Pedicle angle
• transverse pedicle angle  
• varies from 10deg (mid thoracic spine) to 30deg (L5)
• sagittal pedicle angle  
• 15-17deg cephalad for majority of thoracic spine
• neutral (0deg) for lumbar spine except L5 (caudal)

C6 > C5 > C7 > C4 > C3


hyperextension, lateral compression and rotation of the cervical spine

type a-seperation fracture unilat lamina and pedicle

type b- multiple fracture lines with lateral wedging

type c-Vertical fracture line in the coronal plane, with invagination of the superior articular process of the caudal vertebra

type d-Bilateral horizontal fracture lines of the pars interarticularis, leading to separation of the anterior-posterior spinal elements

• nstability 
• >3.5mm displacement
• >10deg kyphosis
• >10deg rotation difference compared with adjacent vertebra

• C-D: distance from basion to posterior arch
• A-B: distance from anterior arch to opisthion

if over 1 worry about anterior dislocation

• Harris rule of 12 12mm suggests occipitocervical dissociation
•  basion-dens interval or basion-posterior axial interval 
• >12mm suggest occipitocervical dissociation
• CT

• he safe zone for occipital screws is located within an area measuring 20mm lateral to the external occipital protuberance along the superior nuchal line  
• the major dural venous sinuses are located just below the external occipital protuberance and are at risk of penetrative injury during occipitocervical fusion

s. aureus

consider tb if not improving

salmonella in sickle cell

n pediatric patients, blood vessels extend from the cartilaginous end plate into the nucleus pulposus

therefore more common in pediatric

• hyperextension
• leads to fracture of pars
• secondary flexion
• tears PLL and disc allowing subluxation

• hangmann fracture
•