Amol cranio vertebralanomalies-21-10-14

Cranio-Vertebral Cranio-Vertebral AnomaliesAnomalies

DR AMOL GULHANEDR AMOL GULHANE

ClassificationClassificationII Bony AnomaliesBony Anomalies

AA Major AnomaliesMajor Anomalies

1 Platybasia1 Platybasia

2 Occipitalization2 Occipitalization

3 Basilar Invagination3 Basilar Invagination

4 Dens Dysplasia4 Dens Dysplasia

5 Atlanto- axial dis5 Atlanto- axial dis

B Minor Anomalies1Dysplasia of Atlas2Dysplasia of occipital condyles clivus etc

II Soft Tissue anomalies1 Arnold-Chiari Malformation2 Syringomyelia Syringobulbia

OSSIFICATION CENTRESOCCIPUT amp BASIOCCIPUT2 occipital squamous portions ndash2 centresBasiocciput(clivus) -1 centre2 Jugular tubercles ndash2 centres2 Occipital condylesndash2 centres

ATLAS ossifies from 3 centresEach half of post Arch with lateral mass unites at 3 ndash4 yearsAnterior arch unites with lateral mass at 6 ndash8 years

AXIS ossifies from 5 primary amp 2 secondary centres

2 Neural arches ndash2 centres appear at 7 ndash8 wkBody of axis ndash1 centre appear at 4 ndash5 monthsBody of dens ndash2 centres appear at 6 ndash7 months4 pieces (at birth) unite at 3 ndash6 years

Tip of odontoid appears at 3 ndash6 years unites with the body of odontoid at 12 years

Cerebellar tonsils

medulla

Vertebral artery

basion

Medulla oblongata

basion

Anterior arch of atlas

Atlas (anterior arch)

Transverse lig atlasDens of axis

Medulla oblongata

Vertebral artery

Atlas posterior arch

Atlas lateral mass

Transverse ligament of atlas

Transverse process and foramen transversarium

Anterior longitudinal ligament

Apical ligament of dens

Tectorial membrane



Dens of axis (C2)

Clivus

Anterior atlanto-occipital membrane

Atlas (lateral mass)

Axis

Int carotid artery

Alar ligaments

Atlanto-axial jointAtlanto-occipital joint

Anatomical and Radiological AspectsAnatomical and Radiological Aspectsbull Anatomical LandmarksAnatomical Landmarks

bull Nasion Nasion -the middle point of the junction of the frontal and the two nasal bones (fron-the middle point of the junction of the frontal and the two nasal bones (frontonasal suturetonasal suture

bull Clivus Clivus bull BasionBasion --the midpoint of the anterior border of the foramen magnumthe midpoint of the anterior border of the foramen magnumbull OpisthionOpisthion-- posterior margin of the foramen magnum posterior margin of the foramen magnum bull

bull Lines angles and indexesLines angles and indexesbull Chamberlainrsquos LineChamberlainrsquos Linebull McGregorrsquos LineMcGregorrsquos Linebull McRaersquos LineMcRaersquos Linebull Klaus Height IndexKlaus Height Indexbull AT IndexAT Index

bullBasal AnglebullBoogardrsquos anglebullBullrsquos anglebullA-O intervalbullEDFM

CRANIOMETRYCraniometry of the CVJ uses a series of lines planes amp angles to define the normal anatomic relationships of the CVJ

These measurements can be taken on plain X rays 3D CT or on MRI

The Chamberlainrsquos lineThe Chamberlainrsquos line

NAME amp SYNONYMS OF LINES

DEFINITION NORMAL MEASUREMENT IMPLICATIONS

Chamberlain lsquos line Palato-occipital line

Posterior pole of hard palate to the Opisthion

Tip of the dens usually below and upto 3 mm above this line

Dens gt 6mm in basilar impression

H O

Significance

An abnormal superior position of the odontoid indicates basilar impression

Common precipitating causes include platybasia atlas occipitalization and bone-softening diseases of the skull base (eg Pagetrsquos disease osteomalacia and fibrous dysplasia)

Occasionally rheumatoid arthritis may also precipitate this deformity

A drawn from the posterosuperior margin of the hard palate to the most inferior surface of the occipital bone

The McGregorrsquos line

The McGregorrsquos lineThe McGregorrsquos line

H

Low occiput



Mc Gregorrsquos lineBasal lineMOST ACCURATE

Postero-superior margin of Hard palate ndash most inferior surface of occipital bone

Odontoid apex shouldnrsquot lie above lt 5mm

Superior lie of odontoid indicates basilar impression(gt5mm)

Low occiput

The McRaersquos lineThe McRaersquos line

B O

Mc Raersquos lineFormen magnum line

Anterior and posterior ends of formen magnum(Basion and Opisthion)

Inf margin of occiput should lie at below this line Tip of dens does not exceed this line Perpendicular line along odontoid intersects 1st line in its anterior quadrant

Inf margin of occiput lies superior ndash Basilar imp

If sagittal diameter lt 20mm neurological symptoms (+) (foramen magnum stenosis)

Significance

If the inferior margin of the occipital bone is convex in a superior direction andor lies above this line then basilar impression is present

Predisposing causes include platybasia occipitalization rheumatoid arthritis and bone-softening diseases (eg Pagetrsquos disease osteomalacia and fibrous dysplasia)

If the odontoid apex does not lie in the ventral quarter of this line a dislocation of the atlanto-occipital joint or a fracture or dysplasia of the dens may be present

Clivus-Canal lineClivus-Canal line

C

B

OC2

H

N



Wackenhiersquos lineClivus canal line

Drawn along clivus into cervical canal

Odontoid tip is ventral and tangential to line

Odontoid transects the line in basilar imp

Basilar AngleWelckerrsquos basilar angle Martinrsquos basilar angle sphenobasilar angle

LandmarksThree points are located and joined together by two lines the subsequent angle is measured

The three points are the nasion (frontal-nasal junction) the center of the sella turcica (midpoint between the clinoid processes) and the basion (anterior margin of the foramen magnum)

The average normal angle subtended by these two lines is 137deg with a normal variation of 123-152deg

Significance

The measurement is an index of the relationship between the anterior skull and its base

The angle will increase beyond 152deg in platybasia in which the base is elevated in relation to the rest of the skull

This may or may not be associated with basilar impression

The deformity may be congenital (isolated impression occipitalization) or acquired (Pagetrsquos disease rheumatoid arthritis fibrous dysplasia)

Basilar AngleBasilar Angle

Mid sella

B

N

S

B

N



Basilar angle Welckerrsquos Martinrsquos Spheno-BA

Nasion ndash Centre of the sella ndash Basion

Angle 1370 (123-1520)

gt1520 Platybasia(Base is elevated)+- Basilar impression

Modified MRI techniqueThis technique described by Koenigsbert et al yields a normal value range (95 CI) 116deg - 118deg for adults and 113deg - 115deg for children Angle formed by line extending across the anterior cranial fossa to the tip to the dorsum sellae line drawn along the posterior margin of the clivus

The Boogardrsquos lineThe Boogardrsquos line

N

O



Boogard lsquos Line Nasion to Opisthion Basion should lie below this line

Altered in basilar impression

Boogardrsquos angleBoogardrsquos angle

Tuberculum sellaTuberculum sella

B o

N

Mc Ray

s

C



Boogard lsquos Angle Angle intersected by1st line between Dorsum sellae to Basion amp Mc Raersquos line

119-1350

Average - 1220

gt 1350

Basillar impression

Boogardrsquos angle

MethodMethod of Bull of Bull

C2

Atlas plane

Chamberlain

Bull lsquos angle Atlanto-palatine angle

Posterior Angle betn 1st line from Post tip of hard palate to post margin of foramen magnum 2nd line betn ant amp post tubercles of atlas

Post angle lt130 If odontoid is tilted posteriorly or in case of change of atlas position The angle gt 130

Ranawat methodRanawat method

C2

C1

Ranawat method Line joining center of the anterior arch of C1 to post ring amp another line along the axis of the odontoid from the centre of the pedicle of C2 to 1st line

Normal distance between C-1 and C-2 in Men averages 17 mm (plusmn2 mm SD) Women 15 mm (plusmn 2 mm SD)

A decrease in this distance indicates cephalad migration of C-2

C2

C1

C2

C1

PEDICLE

Schmidt ndash Fischer AngleSchmidt ndash Fischer Angle (ATLANTO-OCCIPITAL JT AXIS ANGLE)(ATLANTO-OCCIPITAL JT AXIS ANGLE)

O

C2AA JT

AO JT

C1 C1



Schmidt ndash Fischer Angle

Angle of axis of Atlanto-Occipital joint

125 +- 2 degrees Angle is wider in condylar hypoplasia

CRANIO-VERTEBRAL ANGLECRANIO-VERTEBRAL ANGLE

ax

C



Cranio vertebral angle Between clivus line and post axial line

Flexion ndash 1500

Extension - 1800

lt1500 Platybasiacord compressionBasilar impression

bullBDI less than 85 mm compared with 12 mm on data from plain radiographs

bullAn ADI less than 2 mm compared with 3 mm previously accepted

Midsagittal MDCT image of the craniocervical junction demonstrates the BDI(basion-dental interval) as the distance from the most inferior portion of the basion to the closest point of the superior aspect of the dens

MDCT VS PLAIN RADIOGRAPHY IN CRANIOMETRYhellip

MDCT image of the craniocervical junction demonstrates the ADI which is calculated by drawing a line from the posterior aspect of the anterior arch of C1 to the most anterior aspect of the dens at the midpoint of the thickness of the arch in craniocaudal dimension

Atlantodental Interspace (ADI)SynonymsAtlas-odontoid space predental interspace atlas-dens interval

Flexion is the optimum view to assess the interspace because in this position the most stress is placed on the transverse ligament of the atlas

Normal Values for Atlantodental Interspace

Adults 1 to 3 mm

Children1 to 5 mm

Significance

A decreased space is to be expected with advancing age because of degenerative joint disease of the atlantodental joint

A more significant change is an abnormally widened space with reduction in the neural canal size

The most frequent causes include trauma occipitalization Downrsquos syndrome pharyngeal infections and inflammatory arthropathies (eg ankylosing spondylitis rheumatoid arthritis psoriatic arthritis and Reiterrsquos syndrome)

Sagittal CT images right measures the basion-posterior axial line interval which is denoted by the small horizontal red line

The left image demonstrates measurement of the basion-dental interval which is denoted by the vertical red line

If either of these distances are greater than 12 mm then the diagnosis of occipitocervical dissocation is fairly certain

The basion-posterior axial line interval (BAI) is drawn along the posterior aspect of the dens (the posterior axial line) and a measurement between this line and the tip of the basion is performed

Harris Lines or the Rule of Twelve

The Powers ratio can be measured to determine if there is anterior occipitoatlantal dissociation The Powers ratio is the distance between the basion and the posterior spinolaminar line of C1 (BC) divided by the distance between the anterior arch of C1 and the opisthion (AO) If the Powers Rule (BC)(AO) is greater than 1 then anterior occipitoatlantal dissocation has likely occurred

The accuracy of the Powers ratio is controversial since it can be difficult to locate the position of the basion and the opisthion on the lateral skull radiograph It is easier to obtain on sagittal CT

Sagittal MDCT image of the craniocervical junction demonstrates the AOI which is calculated by drawing a line perpendicular to the articular surfaces of the occipital condyle and the lateral mass of C1 This line is drawn at the center of the articulation by correlating the sagittal and coronal images

bullThe AOI demonstrated 95 of the population ranged between 05 mm and 14 mm

AP open mouth

If the lateral margin of the atlas lateral mass lies lateral to the lateral axis margin this may be a radiologic sign of Jeffersonrsquos fracture odontoid fracture alar ligament instability or rotatory atlantoaxial subluxation

Atlantoaxial Alignment

ATLANTOAXIAL ALIGNMENT

A Normal Alignment

B Abnormal Alignment The abnormality (arrow) is the result of a Jeffersonrsquos fracture of the atlas

Table Lines and angles used in radiologic diagnosis of CV anomalies

Parameter Normal range limits

A PLATYBASIA

B BASILAR INVAGINATION

C ATLANTO-AXIAL DISLOCATION

bull Basal angle lt 150 degree

bull Boogardrsquos angle lt 136 degree

bull Bullrsquos angle lt 13 degree

bull Chamberlainrsquos line lt one third of odontoid above this linebull Mcgregorrsquos line lt 5 mmbull Mcrae line odontoid lies below thisbull Klaus height index gt 35 mmbull Atlanto-temporo gt 22mm mandibular index

bull Atlanto-odontoid space upto 3 mm in adults upto 5 mm in childrenbull EDFM gt 19mm

RADIOLOGY OF CVJ(NORMAL VARIANTS amp ANOMALIES)

THE OCCIPUT The basiocciput forms the lower portion of the clivus

The upper portion of the clivusis formed by the basisphenoid separated from the basiocciput by the sphenooccipital synchondrosis

The age at which this synchondrosis fuses ranges from ldquoafter the twelvth yearrdquoto 14-16 years for girls and 16-185 years for boys

Most occipital anomalies are associated with decreased skull base height and basilar invagination

Condylus Tertius

Anomalies and malformations of the most caudal of the occipital sclerotomes are collectively termed lsquo lsquomanifestations of occipital vertebraerdquo

When the hypochordal bow of the fourth occipital sclerotome (proatlas) persists or when the proatlas fails to integrate an ossifledremnant may be present at the distal end of the clivus called the condylus tertius or third occipital condyle

This third condyle may form a joint or pseudojoint with theodontoid process or with the anterior arch of the atlas and may lead to limitation in therange of motion of the CVJ

There is an increased prevalence of os odontoideum associatedwith this abnormality

The occipital bone is composed of asioccipital exoccipital and supraoccipital portions enclosing the foramen magnum

Condylus tertius and platybasia Midsagittal Ti-weighted MR image revealsmarked skull base flattening with a Welcher basal angle of 150 dotted line) Note the marked bowstring deformity of the cervicomedullary junctionThe C-1 arch (A) lies directly above the tip of the odontoid process (0) Marrow within accessory ossification centers (condylus tertius)

Condylar Hypoplasia

In condylar hypoplasia the occipital condyles are underdeveloped and have a flattened appearance leading to basilar invagination (violation of the Chamberlain line) and widening of the atlantooccipital joint axis angle

The tip of the odontoid process and the lateral masses of the atlas typically lie below a line connecting the mastoid tips (bimastoid line) this relationship is violated in condylar hypoplasia

The lateral masses of the atlas may be fused to the hypoplastic condylesfurther accentuating the basilar invagination

Clinically condylar hypoplasia limits or may even abolish movements at the atlantooccipital joint and may occasionally lead tocompression of the vertebral artery secondaryto excessive posterior gliding of the occiput inrelation to the atlas

image

PLATYBASIA

BASILAR IMPRESSION

BASILAR INVAGINATION

These terms are not synonymous

PLATYBASIAMartinrsquos anamoly

Flattening of angle between the clivus and the body of the sphenoid CFPRIMARY- Isolated or in conjunction with other dysplasias like Achondroplasia Osteogenesis imperfecta

SECONDARY - Pagetrsquos disease bone softening degenerative diseaseBasilar angle gt 152deg(N=123-1520)

Craniovertebral = clivus-canal angle becomes acute (lt150deg) MC associated changes - Basilar invagination anomalies of C1(occipitalisation)block vertebra Klippel-Feil syndrome


Basilar invagination implies that the floor of the skull is indented by the upper cervical spine amp hence the tip of odontoid is more cephalad protruding into the FM

There are two types of basilar invagination primary invagination which is developmental and more common secondary invagination which is acquired

Primary invagination can be associated with occipitoatlantal fusion hypoplasia of the atlas a bifid posterior arch of the atlas odontoid anomalies

In BI all three parts of the occipital bone (basiocciput exoccipitalamp squamous occipital bone) are deformed

Topographic types of BI Anterior BI hypoplasia of the basilar process of the occipital boneBI of the occipital condyles(ParamedianBI)ndashCondylar hypoplasiaBI in the lateral condylar areaPosterior BI posterior margin of the FM is invaginatedUnilateral BIGeneralised BI

BI is associated with high incidence of vertebral artery anomaliesAbnormal curvature of VA is due to the fact that they are of normal length amp course through a reduced bone space (wide angle bw 3rd amp 4th part of VA)

SIGNS SYMPTOMS usually occur in 2nd or 3rd decade

Short neck(78)torticollis (68)

ss of associated ACM (cerebellaramp vestibular disturbances) amp syringomyelia(25 to 35)

Motor amp sensory disturbances (85)

Lower cranial nerves involvement

Headache amp pain in the nape of neck (greater occipital N)

ss of raised ICP (HCP) due to posterior encroachment which causes blockage of aqueduct of sylvius

Compression of cerebellum amp vestibular apparatus leading to vertical or lateral nystagmus(65) (not due to direct pressure from post rim of FM but rather due to a thickened band of dura)

Vertebral artery insufficiency ss

bullBASILAR INVAGINATION

bullFloor of the skull is indented by the upper cervical spine amp hence the tip of odontoid is more cephalad protruding into the FM

bullPrimary invagination can be associated with occipito atlantal fusion hypoplasia of the atlas a bifid posterior arch of the atlas odontoid anomalies bullBI is associated with high incidence of vertebral artery anomalies

Chamberlainrsquos line- tip of dens is gt6mm above this line Mc Gregorrsquos line- tip of dens is gt 5mm above this line Mc Raersquos line- tip of dens is above this line Boogardrsquos line- basion is above this line

BASILAR IMPRESSION (SECONDARY BASILAR INVAGINATION

bull Basilar impression refers to secondary or acquired forms of BI

bull due to softening of the bone amp is seen in conditions such as rickets hyperparathyroidism osteogenesis imperfecta Pagets disease neurofibromatosis skeletal dysplasias and RA amp infection producing bone destruction with or without ligamentous laxity

bullMay be associated with developmental cervical canal stenosis amp also fibrous bands amp dural adhesions at the dorsal cervicomedullary junction


Pagetrsquosdisease Usually symptomatic after 40 years of ageCT shows irregular thick bones with a ldquomoth eatenrdquoappearance of the calvaria

AchondroplasiaGenetically dominant disorder characterized by inhibition of endochondral bone formation

The base of the skull is affected but the membraneous convexity skull bone grows normally

This differential bone growth results in large calvarium on a small baseThe mortality is high in the 1st year of life due to cervicomedullary dysfunction at the FM

A small FM with hypertrophic bone amp a posterior dural shelf results in compression of neural structures

Atlantooccipital Assimilation

failure of segmentation between the skull and first cervical vertebra results in assimilation of the atlas

The assimilation may be cornplete or partial

It invariably results in basilar invagination

Although the Wackenheim clivus baseline may be normalthe clivus-canal angle may be decreased

When incompletely assimilated the atlas arches appeartoo high on the lateral plain radiographor when completely assimilated are not visibleat all

There is an increased prevalence of associated fusion of the axis and third cervical vertebra in association with atlantooccipitalAssimilation

When this is present gradual loosening of the atlantodental jointwith progressive atlantoaxial subluxation mayoccur reported in approximately 50 of cases

TOPOGRAPHIC FORMS (WACKENHEIM)

Type I Occipitalization(generally subtotal) associated with BI

Type II Occipitalization(generally subtotal) associated with BI amp fusion of axis amp 3rdcervical vertebrae

Type III Total or subtotal occipitalizationwith BI amp maldevelopment of the transverse ligament

Type III may be associated with various malformations like C2-C3 fusion hemivertebra dens aplasia tertiary condyle etc

The neurological symptoms are not caused by occipitalization proper but rather by the fact that in the absence of a free atlas TL fails to develop which causes posterior displacement of axis amp compression of the spinal cord

Instability bw atlas amp axis is reducible in patients lt15 yrrsquos but after that irreducible state occurs

ATLAS With the exception of the various atlantooccipital assimilations most atlas anomalies when isolated produce no abnormal CVJ relationships and are not associated with basilar invagination

The vast majority of anomalies consist of various arch clefts aplasias and hypoplasias

Arch anomalies are frequently mistaken for fractures in the evaluation of plain radiographs of patients with a history of cervical spine trauma

The irregular fragments located inferior to the Anterior arch of the atlas may be

mistaken for fracture fragments The clear cortical margins and characteristic location

help to differentiate this variant from a fracture

Accessory ossification centre for the anterior arch of the atlashelliphellip

PONTICULUS POSTICUS KIMMERLErsquoS DEFORMITY

It is a bony ridge projecting posteriorly from the articular edge of the atlas superior articular facet

The bony projection may be only a few mm long or may elongate to unite with the adjacent neural arch of the atlas to produce an ldquoARCUATE CANALrdquothrough which the vertebral artery passes

This is due to ossification of a portion of the oblique A-O ligament

Posterior Arch Anomalies (MC atlas anomaly)

Total or partial aplasia of the posterior atlas arch is rare

Although absence of the posterior arch when isolated is usually asymptomatic but may be associated with anterior atlantoaxial subluxation

Bilateral atlantoaxial subluxation may be associated with both total and partial aplasias simulating the Jefferson fracture

In contrast to the aplasias and hypoplasias clefts of the atlas arches are much more common

Posterior rachischisis most common is observed in 4 of adults

The majority of posterior atlas clefts (97) are midline whereas lateral clefts through the sulcus of the vertebral artery account for the remaining 3

Posterior arch rachischisis may be superimposed on the odontoid process or the axis body on the open-mouth odontoid view simulating a fracture

Posterior arch hemiplasia

Split Atlas

In contrast to posterior arch rachischisis anterior arch rachischisisis quite rare (0 1 )

It is typically encountered in association with posterior rachischisis-ldquosplit atlasrdquo

Normally on a lateral radiograph the anterior arch of the atlas appears crescentic or half-moon-shaped with dense cortical bone surrounding the medullary cavity and a well-defined predental space

In anterior arch rachischisis the anterior arch appears fat or plump and rounded in configuration appearing to lsquolsquooverlaprsquolsquo the odontoid process (making identification of the predental space impossible) the arch may have unsharp duplicated anterior margins

CONGENITAL ODONTOID ANOMALIES OR DYSPLASIAS

Types of dens dysplasia

Type 1 (Os odontoideum) separate odontoid process

Type 2 (Ossiculum terminale) failure of fusion of

apical segment with its base

Type 3 ndash Agenesis of odontoid base amp apical segment

lies separately

Type 4 ndash Agenesis of odontoid apical segment

Type 5 ndashTotal agenesis of odontoid process

Persistent OssiculumTerminaleAlso called Bergman ossicle results from failure of fusion of the terminal ossicle to the remainder of the odontoid process

The fusion typically is accomplished by 12 years of age

Bergman ossicle may be confused with a type 1 odontoid fracture (avulsion of the terminal ossicle) and absolute differentiation between the two diagnoses may be difficult

Whether traumatic or congenital in origin this anomaly is stable when isolated and of relatively little clinical significance

The odontoid process is usually normal in height

the normal dense secondary ossification center for the odontoid process tip which exhibits a characteristic symmetrical V-shaped lucent zone of separation from the body of the dens COMMENT This is a normal finding of the odontoid seen in 25 of patients lt 12 years of age but it is usually not seen after this age at which time it constitutes non-union (ossiculum terminale of Bergmann)

OdontoidAplasia

Total aplasia of the odontoid process is extremely rare

A true aplasia is associated with an excavation defect into the body of axis

may simulate os odontoideum as the os fragment may be perfectly projected over the atlas arch on the open mouth odontoid view

AP Open Mouth Here the odontoid process exists as an abbreviated remnant stump therefore it is not true agenesis The lateral shift of the atlas relative to the axis C1 on C2 indicates instability

OS ODONTOIDEUM

This term first introduced by Giacominiin 1886 refers to an independent osseous structure lying cephalad to the axis body in the location of the odontoid process

The anterior arch of the atlas is rounded and hypertrophic but the posterior arch is hypoplastic

As the gap between the os odontoideum and the axis body usually extends above the level of the superior articular facet of the axis cruciate ligament incompetence and A-A instability are common

The margins of the axis body the os and anterior arch are all well corticated

Type 2 odontoid fracture is typically associated with a flattened sharp uncorticated margin to the upper axis body and a normal half moon-shaped appearance to the anterior atlas arch with a narrow gap in bw segments

Etiology ndashEmbryologic Traumatic ampor Vascular

Types ndashOrthotopicamp Dystopic

Instability is more common with dystopic type

Reduciblendashon flexion dorsal compression of the cord occurs

on extension ventral compression occurs secondary to increased angulation anteriorly

Irreduciblendashdue to displacement of TL ventral to the ossicle

Treatment

Reducible ndashOccipitocervical PF in neutral positionIrreducible ndashTransoral resection of the os odontoidremnant amp surrounding granulation tissue

Os odontoideum is defined as non-union of the dens with the axis body A transverse radiolucent cleft separates an ossicle of variable size from the axis body

Os odontoideumOs odontoideum

OS ODONTOIDEUMOS ODONTOIDEUM Dens hypoplastic amp Dens hypoplastic amp

separate from ossicle by separate from ossicle by variable distancevariable distance

Incompetent cruciate Incompetent cruciate ligmt ligmt Unstable

Corticated smooth Corticated smooth roundround

FRACTUREFRACTURE Narrow gap between Narrow gap between

fractured fragmentsfractured fragments Fracture may lie caudal Fracture may lie caudal

to superior facetto superior facet Jagged edge no cortexJagged edge no cortex

Subluxation

Os odontoideum

Fracture

Atlanto-Axial Instability

bullA RotationalndashAround the dens

bullB TranslationalndashTranslation between C1ndashC2 where transverse lig is disrupted

bullC DistractionndashIndicating craniocervical dissociation

Non-traumatic conditions associated with increase in the atlanto axial distanceDown syndrome Due to laxity of the transverse ligament Grisel syndrome Atlantoaxial subluxation associated with inflammation of adjacent soft tissues of the neck Rheumatoid arthritisFrom laxity of the ligaments and destruction of the articular cartilage Osteogenesis imperfectaNeurofibromatosis Morquio syndrome Secondary to odontoid hypoplasia or aplasiaOther arthridities (PsoriasisLupus)

On the open mouth odontoid view the combined spread of the lateral masses of C1 greater than 69 mm would indicate rupture of the transverse ligamentAn atlantoaxial distance greater than 4-5 mm by lateral radiographs is indicative of AAI Posterior atlanto dental interval (PADI) Normal range is 19 ndash32 mm in male amp 19 ndash30mm in femalesBelow 19mm neurological manifestations occur

WADIA CLASSIFICATION Group I AAD with occipitalization of atlas amp fusion of C2 amp C3Group II odontoid incompetence due to its maldevelopment with no occipitalization of atlasGroup III odontoid dislocation but no maldevelopment of dens or occipitalization of atlas

Incidence of AAD ndash

57 of all CVJ anomalies83 of all causes of cervical compression

ATLANTO-AXIAL DISLOCATION OR INSTABILITY

Posterior atlanto dental interval (PADI) measured from the posterior border of the dens to the anterior border of the posterior tubercle

This index may be more important because it more directly assesses the space available to the spinal cord

Normal range for the distance behind the dens is 19 ndash32 mm in male amp 19 ndash30mm in females

Below 19mm neurological manifestations occur

Rotatory displacement (Fielding and Hawkins classification)Type I is simple rotatory displacement with an intact transverse ligamentType II injuries involve anterior displacement of C1 on C2 of 3-5 mm with one lateral mass serving as a pivot point and a deficiency of the transverse ligamentType III injuries involve greater than 5 mm of anterior displacementType IV injuries involve the posterior displacement of C1 on C2

Type I injuries (stable subluxations) ndashCollar

Type II injuries may be potentially unstable

Type III and IV rotatory displacements that are unstable are treated surgically with a reduction and C1-2 fusion

Non-traumatic conditions associated with increase in the atlantoaxial distance

Down syndrome Due to laxity of the transverse ligament Grisel syndrome Atlantoaxial subluxation associated with inflammation of adjacent soft tissues of the neck Rheumatoid arthritisFrom laxity of the ligaments and destruction of the articular cartilage Osteogenesis imperfectaNeurofibromatosis Morquio syndrome Secondary to odontoid hypoplasia or aplasiaOther arthridities(PsoriasisLupus)

RHEUMATOID ARTHRITIS amp CVJ

First described by Garrodin 189020 of the patients with RA have AAD

AAD is due to loss of tensile strength amp stretching of TL due to destructive inflammatory changes as well as secondary degenerative changes in tissues from vasculitis

Similar changes occur in the median amp lateral joints which result in erosive changes in adjacent bone amp formation of granulation tissue in the synovial joints

Odontoid process ndashosteoporosis angulation

OCCIPITO-ATLANTAL INSTABILITY1048708Traumatic non traumatic

1048708Traumatic usually fatal 8 incidence in RTA1048708Seen with cardiorespiratory arrest quadriplegia loss of autonomic function VA insufficiency etc

1048708Traynelis classification1048708Type I anterior displacement of occiput on atlas1048708 Type II vertical displacement bw occiput amp cervical spine1048708Type III posterior displacement of occiput on atlas

TRAUMATIC LESIONS OF CVJ

OF ATLASPosterior arch 23rdof all occur at the junction of posterior arch amp lateral mass (hyperextension injury)Anterior arch rareJefferson s burst of atlas 1st described by Geoffrey jefferson in 1920

Axial loading ndashdownward displacement of condyles with separation of lateral mass of C1Classically 4 part -2 each in ant amp post archneck pain amp stiffnessCervical collar Halo immobilizationNon union ndashocciputto C2 fusion

open-mouth show lateral spine dispalcement of lateral masses of C1

CT scan of C1 shows fratures through anterior and posterior rings of C1

HANGMANrsquoS ( TRAUMATIC SPONDYLOLISTHESIS OF AXIS )ldquoJudicial Hangingrdquo-submental knots causes dislocation of neural arch of axisToday majority due to RTA

Two basic mechanisms

Hyperextension amp distractionHyperextension amp compression

Type I are either non-displaced or have no angulationamp lt3mm of displacement (stable injury with uncommon neurological deficits)

Type II with significant angulationamp translation of anterior fragment

Type III with severe angulationamp displacement along with concomitant UL or BL facet dislocation

Neck pain but neurological deficits lessSurgical Rx seldom required due to high chances of spontaneous interbody fusion amp healingMost managed by reduction amp external immobilization

Radiographic features (best seen on lateral view)

1 Prevertebral soft tissue swelling2 Avulsion of anterior inferior corner of C2 associated with rupture of the anterior longitudinal ligament3 Anterior dislocation of the C2 vertebral body4 Bilateral C2 pars interarticularis fractures

Hangmans Fracture- through pars of c2

Hangmans Fracture

Traumatic spondylolisthesis of C2 Fractures of the lamina articular facets pedicles or pars interarticulares of C2 with disruption of C2-C3 junction

Axial CT image of the cervical spine at C2 level shows fractures of bilateral C2 pars interarticulares The fracture on the right extends to the transverse foramen where the right vertebral artery is located

ODONTOID Constitute about 7 ndash14 of cervical spine Flexion is the MC mechanism of injury causing anterior displacement of C1 on C2

Anderson amp DrsquoAlonzo classificationndashType I oblique avulsion through the upper part of the odontoid process at the point of alar ligament attachmentType II occur at the junction of the odontoid process amp the body of axisType III extend down in to the body of axis

ODONTOID

Type I are stable amp heal well if immobilised in a collar or brace

Type III are usually stable skull traction fb halo or brace for 3 ndash4 months results in fusion

Type II are prone to non union with a failure rate of 30 -60 with conservative measuresIndications for Sxndashdisplacement gt= 5mm nonunion age gt7 years disruption of the TLOdontoid compression screws (acute type II ) C1-2 arthrodesis(wiring fusion transarticular screws)

CHIARI MALFORMATION

The Chiari malformations are a group of hindbrain herniation syndromes initially described by Austrian pathologist Hans Chiari in 1891

Types of Chiari malformations Type I Caudal descent of cerebellar tonsils in cervical spine Osseous anomalies of posterior skull base and spine

It presents in early adulthood rather than at birthAssociated with syringomyelia in 50 to 70

Type II Caudal descent of cerebellar vermis and brain stem into cervical spine

Open spinal dysraphismHydrocephalusMultiple neuroaxis anomalies

Type III Craniocervical encephalocele containing portions of cerebellum and brain stem

HydrocephalusType IV (Controversial not commonly accepted as a Chiarimalformation)

Aplasiahypoplasia cerebellum

ARNOLD-CHIARI MALFORMATION I Present in adulthood =cerebellar tonsillar ectopia Herniation of cerebellar tonsils gt 5mm below a line connecting Basion with Opisthion (= foramen magnum)

Causesbull small posterior fossabullcerebellar overgrowthbulldisproportionate CSF absorptionAssociated with1 Syringohydromyelia (30-56)2 Hydrocephalus (25-44)3 Malformation of skull base

NECTEffaced Posterior Fossa cisterns Crowded Foramen Magnum Lateral3rd ventricles usually normal

ARNOLD-CHIARI MALFORMATION II

Radiography Lucken shadel -Craniolacunia = Lacunar Skull = mesenchymal dysplasia of calvarial ossificationAbsent Hypoplastic posterior arch of C1

Myelography Tethered cord

NECT Small posterior fossa Large funnel-shaped foramen magnum Scalloped petrous pyramid notched clivus Absent falx cerebelli

ARNOLD-CHIARI MALFORMATION III

bull High cervical occipital meningoencephalocele + intracranial Chiari 2malformation

NECTo Occipital squamo defectPosterior spina bifida at the P1ndashP2 levelo Bony features of Chiari 2Small posterior cranial fossa scalloped clivus lacunar skullMR FindingsTIWI Sac contentsbull Meninges cerebellum plusmn brain stembull Cisterns 4th ventricle dural sinuses o HydrocephalusT2WI Tissues in sac may be bright (gliosis)MRV plusmn Veins in cephalocele

NEOPLASMS OF CVJ

Unusual Metastatic malignancies such as carcinoma of the breast lung prostate kidney and thyroid in adults

and neuroblastoma Ewingrsquos tumor leukemia hepatoma and retinoblastoma in children are most commonPrimary malignancies involving the craniocervical junction are rare(multiple myeloma)

Benign tumors are very rare

THANK YOUTHANK YOU

ClassificationClassificationII Bony AnomaliesBony Anomalies

AA Major AnomaliesMajor Anomalies

1 Platybasia1 Platybasia

2 Occipitalization2 Occipitalization

3 Basilar Invagination3 Basilar Invagination

4 Dens Dysplasia4 Dens Dysplasia

5 Atlanto- axial dis5 Atlanto- axial dis

B Minor Anomalies1Dysplasia of Atlas2Dysplasia of occipital condyles clivus etc

II Soft Tissue anomalies1 Arnold-Chiari Malformation2 Syringomyelia Syringobulbia






Cerebellar tonsils

medulla

Vertebral artery

basion

Medulla oblongata

basion




Medulla oblongata

Vertebral artery


Atlas lateral mass





Tectorial membrane



Dens of axis (C2)

Clivus



Axis

Int carotid artery

Alar ligaments
















H O

Significance







H

Low occiput







Low occiput


B O






Significance





C

B

OC2

H

N











Significance






Mid sella

B

N

S

B

N





Angle 1370 (123-1520)




N

O







B o

N

Mc Ray

s

C




119-1350

Average - 1220

gt 1350

Basillar impression

Boogardrsquos angle


C2

Atlas plane

Chamberlain





C2

C1




C2

C1

C2

C1

PEDICLE


O

C2AA JT

AO JT

C1 C1







ax

C




Flexion ndash 1500

Extension - 1800










Adults 1 to 3 mm

Children1 to 5 mm

Significance













AP open mouth




A Normal Alignment




A PLATYBASIA













Condylus Tertius







Condylar Hypoplasia





image

PLATYBASIA

BASILAR IMPRESSION








































































Split Atlas











lies separately









OdontoidAplasia





OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU






Cerebellar tonsils

medulla

Vertebral artery

basion

Medulla oblongata

basion




Medulla oblongata

Vertebral artery


Atlas lateral mass





Tectorial membrane



Dens of axis (C2)

Clivus



Axis

Int carotid artery

Alar ligaments
















H O

Significance







H

Low occiput







Low occiput


B O






Significance





C

B

OC2

H

N











Significance






Mid sella

B

N

S

B

N





Angle 1370 (123-1520)




N

O







B o

N

Mc Ray

s

C




119-1350

Average - 1220

gt 1350

Basillar impression

Boogardrsquos angle


C2

Atlas plane

Chamberlain





C2

C1




C2

C1

C2

C1

PEDICLE


O

C2AA JT

AO JT

C1 C1







ax

C




Flexion ndash 1500

Extension - 1800










Adults 1 to 3 mm

Children1 to 5 mm

Significance













AP open mouth




A Normal Alignment




A PLATYBASIA













Condylus Tertius







Condylar Hypoplasia





image

PLATYBASIA

BASILAR IMPRESSION








































































Split Atlas











lies separately









OdontoidAplasia





OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU

Medulla oblongata

basion




Medulla oblongata

Vertebral artery


Atlas lateral mass





Tectorial membrane



Dens of axis (C2)

Clivus



Axis

Int carotid artery

Alar ligaments
















H O

Significance







H

Low occiput







Low occiput


B O






Significance





C

B

OC2

H

N











Significance






Mid sella

B

N

S

B

N





Angle 1370 (123-1520)




N

O







B o

N

Mc Ray

s

C




119-1350

Average - 1220

gt 1350

Basillar impression

Boogardrsquos angle


C2

Atlas plane

Chamberlain





C2

C1




C2

C1

C2

C1

PEDICLE


O

C2AA JT

AO JT

C1 C1







ax

C




Flexion ndash 1500

Extension - 1800










Adults 1 to 3 mm

Children1 to 5 mm

Significance













AP open mouth




A Normal Alignment




A PLATYBASIA













Condylus Tertius







Condylar Hypoplasia





image

PLATYBASIA

BASILAR IMPRESSION








































































Split Atlas











lies separately









OdontoidAplasia





OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU



Medulla oblongata

Vertebral artery


Atlas lateral mass





Tectorial membrane



Dens of axis (C2)

Clivus



Axis

Int carotid artery

Alar ligaments
















H O

Significance







H

Low occiput







Low occiput


B O






Significance





C

B

OC2

H

N











Significance






Mid sella

B

N

S

B

N





Angle 1370 (123-1520)




N

O







B o

N

Mc Ray

s

C




119-1350

Average - 1220

gt 1350

Basillar impression

Boogardrsquos angle


C2

Atlas plane

Chamberlain





C2

C1




C2

C1

C2

C1

PEDICLE


O

C2AA JT

AO JT

C1 C1







ax

C




Flexion ndash 1500

Extension - 1800










Adults 1 to 3 mm

Children1 to 5 mm

Significance













AP open mouth




A Normal Alignment




A PLATYBASIA













Condylus Tertius







Condylar Hypoplasia





image

PLATYBASIA

BASILAR IMPRESSION








































































Split Atlas











lies separately









OdontoidAplasia





OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU

Atlas lateral mass





Tectorial membrane



Dens of axis (C2)

Clivus



Axis

Int carotid artery

Alar ligaments
















H O

Significance







H

Low occiput







Low occiput


B O






Significance





C

B

OC2

H

N











Significance






Mid sella

B

N

S

B

N





Angle 1370 (123-1520)




N

O







B o

N

Mc Ray

s

C




119-1350

Average - 1220

gt 1350

Basillar impression

Boogardrsquos angle


C2

Atlas plane

Chamberlain





C2

C1




C2

C1

C2

C1

PEDICLE


O

C2AA JT

AO JT

C1 C1







ax

C




Flexion ndash 1500

Extension - 1800










Adults 1 to 3 mm

Children1 to 5 mm

Significance













AP open mouth




A Normal Alignment




A PLATYBASIA













Condylus Tertius







Condylar Hypoplasia





image

PLATYBASIA

BASILAR IMPRESSION








































































Split Atlas











lies separately









OdontoidAplasia





OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU



Tectorial membrane



Dens of axis (C2)

Clivus



Axis

Int carotid artery

Alar ligaments
















H O

Significance







H

Low occiput







Low occiput


B O






Significance





C

B

OC2

H

N











Significance






Mid sella

B

N

S

B

N





Angle 1370 (123-1520)




N

O







B o

N

Mc Ray

s

C




119-1350

Average - 1220

gt 1350

Basillar impression

Boogardrsquos angle


C2

Atlas plane

Chamberlain





C2

C1




C2

C1

C2

C1

PEDICLE


O

C2AA JT

AO JT

C1 C1







ax

C




Flexion ndash 1500

Extension - 1800










Adults 1 to 3 mm

Children1 to 5 mm

Significance













AP open mouth




A Normal Alignment




A PLATYBASIA













Condylus Tertius







Condylar Hypoplasia





image

PLATYBASIA

BASILAR IMPRESSION








































































Split Atlas











lies separately









OdontoidAplasia





OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU

Clivus



Axis

Int carotid artery

Alar ligaments
















H O

Significance







H

Low occiput







Low occiput


B O






Significance





C

B

OC2

H

N











Significance






Mid sella

B

N

S

B

N





Angle 1370 (123-1520)




N

O







B o

N

Mc Ray

s

C




119-1350

Average - 1220

gt 1350

Basillar impression

Boogardrsquos angle


C2

Atlas plane

Chamberlain





C2

C1




C2

C1

C2

C1

PEDICLE


O

C2AA JT

AO JT

C1 C1







ax

C




Flexion ndash 1500

Extension - 1800










Adults 1 to 3 mm

Children1 to 5 mm

Significance













AP open mouth




A Normal Alignment




A PLATYBASIA













Condylus Tertius







Condylar Hypoplasia





image

PLATYBASIA

BASILAR IMPRESSION








































































Split Atlas











lies separately









OdontoidAplasia





OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU

Alar ligaments
















H O

Significance







H

Low occiput







Low occiput


B O






Significance





C

B

OC2

H

N











Significance






Mid sella

B

N

S

B

N





Angle 1370 (123-1520)




N

O







B o

N

Mc Ray

s

C




119-1350

Average - 1220

gt 1350

Basillar impression

Boogardrsquos angle


C2

Atlas plane

Chamberlain





C2

C1




C2

C1

C2

C1

PEDICLE


O

C2AA JT

AO JT

C1 C1







ax

C




Flexion ndash 1500

Extension - 1800










Adults 1 to 3 mm

Children1 to 5 mm

Significance













AP open mouth




A Normal Alignment




A PLATYBASIA













Condylus Tertius







Condylar Hypoplasia





image

PLATYBASIA

BASILAR IMPRESSION








































































Split Atlas











lies separately









OdontoidAplasia





OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU















H O

Significance







H

Low occiput







Low occiput


B O






Significance





C

B

OC2

H

N











Significance






Mid sella

B

N

S

B

N





Angle 1370 (123-1520)




N

O







B o

N

Mc Ray

s

C




119-1350

Average - 1220

gt 1350

Basillar impression

Boogardrsquos angle


C2

Atlas plane

Chamberlain





C2

C1




C2

C1

C2

C1

PEDICLE


O

C2AA JT

AO JT

C1 C1







ax

C




Flexion ndash 1500

Extension - 1800










Adults 1 to 3 mm

Children1 to 5 mm

Significance













AP open mouth




A Normal Alignment




A PLATYBASIA













Condylus Tertius







Condylar Hypoplasia





image

PLATYBASIA

BASILAR IMPRESSION








































































Split Atlas











lies separately









OdontoidAplasia





OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU

Significance







H

Low occiput







Low occiput


B O






Significance





C

B

OC2

H

N











Significance






Mid sella

B

N

S

B

N





Angle 1370 (123-1520)




N

O







B o

N

Mc Ray

s

C




119-1350

Average - 1220

gt 1350

Basillar impression

Boogardrsquos angle


C2

Atlas plane

Chamberlain





C2

C1




C2

C1

C2

C1

PEDICLE


O

C2AA JT

AO JT

C1 C1







ax

C




Flexion ndash 1500

Extension - 1800










Adults 1 to 3 mm

Children1 to 5 mm

Significance













AP open mouth




A Normal Alignment




A PLATYBASIA













Condylus Tertius







Condylar Hypoplasia





image

PLATYBASIA

BASILAR IMPRESSION








































































Split Atlas











lies separately









OdontoidAplasia





OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU




H

Low occiput







Low occiput


B O






Significance





C

B

OC2

H

N











Significance






Mid sella

B

N

S

B

N





Angle 1370 (123-1520)




N

O







B o

N

Mc Ray

s

C




119-1350

Average - 1220

gt 1350

Basillar impression

Boogardrsquos angle


C2

Atlas plane

Chamberlain





C2

C1




C2

C1

C2

C1

PEDICLE


O

C2AA JT

AO JT

C1 C1







ax

C




Flexion ndash 1500

Extension - 1800










Adults 1 to 3 mm

Children1 to 5 mm

Significance













AP open mouth




A Normal Alignment




A PLATYBASIA













Condylus Tertius







Condylar Hypoplasia





image

PLATYBASIA

BASILAR IMPRESSION








































































Split Atlas











lies separately









OdontoidAplasia





OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU


B O






Significance





C

B

OC2

H

N











Significance






Mid sella

B

N

S

B

N





Angle 1370 (123-1520)




N

O







B o

N

Mc Ray

s

C




119-1350

Average - 1220

gt 1350

Basillar impression

Boogardrsquos angle


C2

Atlas plane

Chamberlain





C2

C1




C2

C1

C2

C1

PEDICLE


O

C2AA JT

AO JT

C1 C1







ax

C




Flexion ndash 1500

Extension - 1800










Adults 1 to 3 mm

Children1 to 5 mm

Significance













AP open mouth




A Normal Alignment




A PLATYBASIA













Condylus Tertius







Condylar Hypoplasia





image

PLATYBASIA

BASILAR IMPRESSION








































































Split Atlas











lies separately









OdontoidAplasia





OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU

Significance





C

B

OC2

H

N











Significance






Mid sella

B

N

S

B

N





Angle 1370 (123-1520)




N

O







B o

N

Mc Ray

s

C




119-1350

Average - 1220

gt 1350

Basillar impression

Boogardrsquos angle


C2

Atlas plane

Chamberlain





C2

C1




C2

C1

C2

C1

PEDICLE


O

C2AA JT

AO JT

C1 C1







ax

C




Flexion ndash 1500

Extension - 1800










Adults 1 to 3 mm

Children1 to 5 mm

Significance













AP open mouth




A Normal Alignment




A PLATYBASIA













Condylus Tertius







Condylar Hypoplasia





image

PLATYBASIA

BASILAR IMPRESSION








































































Split Atlas











lies separately









OdontoidAplasia





OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU


C

B

OC2

H

N











Significance






Mid sella

B

N

S

B

N





Angle 1370 (123-1520)




N

O







B o

N

Mc Ray

s

C




119-1350

Average - 1220

gt 1350

Basillar impression

Boogardrsquos angle


C2

Atlas plane

Chamberlain





C2

C1




C2

C1

C2

C1

PEDICLE


O

C2AA JT

AO JT

C1 C1







ax

C




Flexion ndash 1500

Extension - 1800










Adults 1 to 3 mm

Children1 to 5 mm

Significance













AP open mouth




A Normal Alignment




A PLATYBASIA













Condylus Tertius







Condylar Hypoplasia





image

PLATYBASIA

BASILAR IMPRESSION








































































Split Atlas











lies separately









OdontoidAplasia





OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU





Significance






Mid sella

B

N

S

B

N





Angle 1370 (123-1520)




N

O







B o

N

Mc Ray

s

C




119-1350

Average - 1220

gt 1350

Basillar impression

Boogardrsquos angle


C2

Atlas plane

Chamberlain





C2

C1




C2

C1

C2

C1

PEDICLE


O

C2AA JT

AO JT

C1 C1







ax

C




Flexion ndash 1500

Extension - 1800










Adults 1 to 3 mm

Children1 to 5 mm

Significance













AP open mouth




A Normal Alignment




A PLATYBASIA













Condylus Tertius







Condylar Hypoplasia





image

PLATYBASIA

BASILAR IMPRESSION








































































Split Atlas











lies separately









OdontoidAplasia





OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU


Mid sella

B

N

S

B

N





Angle 1370 (123-1520)




N

O







B o

N

Mc Ray

s

C




119-1350

Average - 1220

gt 1350

Basillar impression

Boogardrsquos angle


C2

Atlas plane

Chamberlain





C2

C1




C2

C1

C2

C1

PEDICLE


O

C2AA JT

AO JT

C1 C1







ax

C




Flexion ndash 1500

Extension - 1800










Adults 1 to 3 mm

Children1 to 5 mm

Significance













AP open mouth




A Normal Alignment




A PLATYBASIA













Condylus Tertius







Condylar Hypoplasia





image

PLATYBASIA

BASILAR IMPRESSION








































































Split Atlas











lies separately









OdontoidAplasia





OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU



N

O







B o

N

Mc Ray

s

C




119-1350

Average - 1220

gt 1350

Basillar impression

Boogardrsquos angle


C2

Atlas plane

Chamberlain





C2

C1




C2

C1

C2

C1

PEDICLE


O

C2AA JT

AO JT

C1 C1







ax

C




Flexion ndash 1500

Extension - 1800










Adults 1 to 3 mm

Children1 to 5 mm

Significance













AP open mouth




A Normal Alignment




A PLATYBASIA













Condylus Tertius







Condylar Hypoplasia





image

PLATYBASIA

BASILAR IMPRESSION








































































Split Atlas











lies separately









OdontoidAplasia





OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU



B o

N

Mc Ray

s

C




119-1350

Average - 1220

gt 1350

Basillar impression

Boogardrsquos angle


C2

Atlas plane

Chamberlain





C2

C1




C2

C1

C2

C1

PEDICLE


O

C2AA JT

AO JT

C1 C1







ax

C




Flexion ndash 1500

Extension - 1800










Adults 1 to 3 mm

Children1 to 5 mm

Significance













AP open mouth




A Normal Alignment




A PLATYBASIA













Condylus Tertius







Condylar Hypoplasia





image

PLATYBASIA

BASILAR IMPRESSION








































































Split Atlas











lies separately









OdontoidAplasia





OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU

Boogardrsquos angle


C2

Atlas plane

Chamberlain





C2

C1




C2

C1

C2

C1

PEDICLE


O

C2AA JT

AO JT

C1 C1







ax

C




Flexion ndash 1500

Extension - 1800










Adults 1 to 3 mm

Children1 to 5 mm

Significance













AP open mouth




A Normal Alignment




A PLATYBASIA













Condylus Tertius







Condylar Hypoplasia





image

PLATYBASIA

BASILAR IMPRESSION








































































Split Atlas











lies separately









OdontoidAplasia





OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU


C2

Atlas plane

Chamberlain





C2

C1




C2

C1

C2

C1

PEDICLE


O

C2AA JT

AO JT

C1 C1







ax

C




Flexion ndash 1500

Extension - 1800










Adults 1 to 3 mm

Children1 to 5 mm

Significance













AP open mouth




A Normal Alignment




A PLATYBASIA













Condylus Tertius







Condylar Hypoplasia





image

PLATYBASIA

BASILAR IMPRESSION








































































Split Atlas











lies separately









OdontoidAplasia





OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU


C2

C1




C2

C1

C2

C1

PEDICLE


O

C2AA JT

AO JT

C1 C1







ax

C




Flexion ndash 1500

Extension - 1800










Adults 1 to 3 mm

Children1 to 5 mm

Significance













AP open mouth




A Normal Alignment




A PLATYBASIA













Condylus Tertius







Condylar Hypoplasia





image

PLATYBASIA

BASILAR IMPRESSION








































































Split Atlas











lies separately









OdontoidAplasia





OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU


O

C2AA JT

AO JT

C1 C1







ax

C




Flexion ndash 1500

Extension - 1800










Adults 1 to 3 mm

Children1 to 5 mm

Significance













AP open mouth




A Normal Alignment




A PLATYBASIA













Condylus Tertius







Condylar Hypoplasia





image

PLATYBASIA

BASILAR IMPRESSION








































































Split Atlas











lies separately









OdontoidAplasia





OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU


ax

C




Flexion ndash 1500

Extension - 1800










Adults 1 to 3 mm

Children1 to 5 mm

Significance













AP open mouth




A Normal Alignment




A PLATYBASIA













Condylus Tertius







Condylar Hypoplasia





image

PLATYBASIA

BASILAR IMPRESSION








































































Split Atlas











lies separately









OdontoidAplasia





OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU









Adults 1 to 3 mm

Children1 to 5 mm

Significance













AP open mouth




A Normal Alignment




A PLATYBASIA













Condylus Tertius







Condylar Hypoplasia





image

PLATYBASIA

BASILAR IMPRESSION








































































Split Atlas











lies separately









OdontoidAplasia





OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU










AP open mouth




A Normal Alignment




A PLATYBASIA













Condylus Tertius







Condylar Hypoplasia





image

PLATYBASIA

BASILAR IMPRESSION








































































Split Atlas











lies separately









OdontoidAplasia





OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU


A Normal Alignment




A PLATYBASIA













Condylus Tertius







Condylar Hypoplasia





image

PLATYBASIA

BASILAR IMPRESSION








































































Split Atlas











lies separately









OdontoidAplasia





OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU



A PLATYBASIA













Condylus Tertius







Condylar Hypoplasia





image

PLATYBASIA

BASILAR IMPRESSION








































































Split Atlas











lies separately









OdontoidAplasia





OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU






Condylus Tertius







Condylar Hypoplasia





image

PLATYBASIA

BASILAR IMPRESSION








































































Split Atlas











lies separately









OdontoidAplasia





OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU


Condylar Hypoplasia





image

PLATYBASIA

BASILAR IMPRESSION








































































Split Atlas











lies separately









OdontoidAplasia





OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU



image

PLATYBASIA

BASILAR IMPRESSION








































































Split Atlas











lies separately









OdontoidAplasia





OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU

PLATYBASIA

BASILAR IMPRESSION








































































Split Atlas











lies separately









OdontoidAplasia





OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU






































































Split Atlas











lies separately









OdontoidAplasia





OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU








lies separately









OdontoidAplasia





OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU







OdontoidAplasia





OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU


OS ODONTOIDEUM












Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU









Treatment











Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU










Subluxation

Os odontoideum

Fracture












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU












































Hangmans Fracture





ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU




ODONTOID




CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU

CHIARI MALFORMATION



















NEOPLASMS OF CVJ




THANK YOUTHANK YOU
















NEOPLASMS OF CVJ




THANK YOUTHANK YOU

THANK YOUTHANK YOU

Amol cranio vertebralanomalies-21-10-14

Health & Medicine

Transcript of Amol cranio vertebralanomalies-21-10-14