CVJ anamolies.pptxAWTAESYDJGFHKGJLHKHJHSGSAFDsa

aesrdtkfhjb.kn,

1. CVJ anomalies – Clinical features, Classification and Management Dr Pradeep Senior Resident

2. CV JUNCTION Is a transition zone between mobile cranium and vertebral column & collectively constitutes the Occiput (posterior skull base), Atlas, Axis and Supporting ligaments. It encloses soft tissue and neural structures of the cervicomedullary junction (medulla, spinal cord & lower cranial nerves)

3. CVJ - LANDMARKS A: Nasion B: Post.pole of Hard Palate C: Ant.arch of atlas D: Dens E: Post.arch of Atlas F: Ophisthion G: Basion H: Tuberculum Sellae A: Tip of Mastoid B: Occipital Condyles C: Dens D: Axis Body E: Lateral masses of Atlas

4. A- nasion B-posterior pole of hard palate C-anterior arch C1 D- odontoid process E-posterior arch C1 F- opisthion G- basion H- tuberculum sellae A B C D E F G H A B C D E A- tip of mastoid process B-occipital condyle C- odontoid process D-axis body E-lateral mass of atlas CVJ - LANDMARKS

5. CRANIOMETRY Craniometry of the CVJ uses a series of lines, planes and angles to determine the normal anatomical relationship of the CVJ. These measurements can be taken on Plain X-Rays, 3D-CT or on MRI. Neither single measurement is helpful nor these are very much specific due to variations in normal anatomical structures and planes within normal range.

6. CHAMBERLAIN’S LINE Posterior margin of hard palate to opisthion Normal- tip of dens is less than 7mm below this line Line from basion to opisthion Normal – tip of dens below this line McRAE’s LINE

7. WACKENHEIM’S LINE Posterior margin of hard palate to lowest part of occipital bone Normal- tip of dens is less than 5mm below this line Line extrapolated along dorsal surface of clivus Normal – dens should be tangential or anterior to this line Mc GREGOR’S LINE

8. DIGASTRIC LINE BIMASTOID LINE Line between incisurae mastoidae Normal- 10mm above atlanto -occipital joint Line between tips of mastoid processes Normal – intersects atlanto -occipital joint

9. WELCHER BASAL ANGLE CLIVUS CANAL ANGLE Angle at junction of nasion-tuberculum and tuberculum-basion lines Normal- 132-140 degree Abnormal->143 degree in platybasia Angle at junction of Wackenheim’s line and posterior vertebral body line Normal – 150-180degree Abnormal-<150 degree in platybasia

10. ATLANTOOCCIPITAL JOINT AXIS ANGLE KLAUS INDEX Angle formed at junction of lines along atlanto -occipital joints Normal -124-127 degree Obtuse in condyle hypoplasia Distance between dens and tuberculum cruciate line Normal-40-41mm Basilar invagination -<30mm Tuberculum Cruciate Line Klaus Height Index IOP

11. Classification Congenital anomalies and malformations of the CVJ Developmental and acquired abnormalities of the CVJ

12. 1. Congenital anomalies and malformations of the CVJ I.A Malformations of the occipital bone 1. Manifestations of the occipital vertebra a. Clivus segmentations b. Remnants around the foramen magnum c. Atlas variants d. Dens segmentation anomalies 2. Basilar invagination 3. Condylar hypoplasia 4. Assimilation of the atlas I.B Malformations of the atlas 1. Assimilation of the atlas 2. Atlantoaxial fusion 3. Aplasia of the atlas arches I.C Malformations of the axis 1. Irregular atlantoaxial segmentation 2. Dens dysplasias a. Ossiculum terminale persistens b. Os odontoideum c. Hypoplasia–aplasia 3. Segmentation failure of C2–C3

13. 2. Developmental and acquired anomalies II.A Abnormalities at the foramen magnum 1. Secondary basilar invagination ( Paget disease, osteomalacia , rheumatoid cranial settling, renal-resistant rickets) 2. Foraminal stenosis (achondroplasia) II.B Atlantoaxial instability 1. Errors of metabolism ( Morquio syndrome) 2. Down syndrome 3. Infections (Grisel syndrome) 4. Inflammatory (rheumatoid arthritis) 5. Traumatic occipito-atlantal and atlantoaxial dislocation; os odontoideum 6. Tumors (neurofibromatosis, syringomyelia) 7. Miscellaneous (fetal warfarin syndrome, Conradi syndrome)

14. Clinical features Head tilt Short neck, low hairline, limitation of neck motion Web neck Neck pain and posterior occipital headache Basilar migraine Hand or foot isolated weakness Quadriparesis/paraparesis/ monoparesis Sensory abnormalities Nystagmus: usually downbeat and lateral gaze Sleep apnea Repeat aspiration pneumonia, dysphagia Tinnitus and hearing loss Vertigo

15. Clinical features Head tilted to one side - patients with rotary luxation of the atlas and the axis or the classic triad of the Klippel- Feil syndrome (abnormally low hairline posteriorly, limitation of neck motion, and a short neck) N eck pain originating in the suboccipital region, with radiation to the cranial vertex occurring in 85% of patients. The central cord syndrome - children with basilar invagination in whom the myelopathy mimics a lower cervical spinal cord disturbance. Sensory abnormalities - neurological deficits related to posterior column dysfunction. Brainstem and cranial nerve deficits - dysphagia and sleep apnea Downbeat nystagmus - compressive lesions of the craniovertebral border with or without an associated hindbrain malformation.

16. ATLANTO AXIAL ASSIMILATION Failure of segmentation of C1 and skull base Association – C2-C3 fusion, atlantoaxial subluxation Complete atlanto -occipital assimilation on right side and incomplete atlanto -occipital assimilation on left side CT - complete atlanto -occipital assimilation ,short clivus ,violation of Chamberlain’s line –basilar invagination and atlantoaxial dislocation

17. Skull base flattening Increased basal angle(>140) Decreased clivus canal angle(<150) Increased welcher basal angle Association – basilar invagination MRI – decreased clivus canal angle , violation of Chamberlain’s line, acute angulation, compression of cervicomedullary junction Platybasia

18. Abnormally high vertebral column Prolapse into skull base Secondary- basilar impression Chamberlain’s line McRae’s line CT - Chamberlain’s line and digastric line, atlantoaxial dislocation ( atlanto dens interval-3.8mm) Basilar invagination

19. BASIOCCIPUT HYPOPLASIA FLATTENED CONDYLES Shortening of clivus Violation of Chamberlain’s line Decreased clivus canal angle Widening of atlanto -occipital joint axis angle(>127°) Causes basilar invagination CT - short clivus , atlantooccipital assimilation and violation of Chamberlain’s line CT - flattened occipital condyles and widening of atlanto -occipital joint axis angle

20. CONGENITAL ANOMALIES - ATLAS Anterior and posterior arch anomalies Total or partial aplasia Isolated anterior arch anomalies –rare Split atlas posterior atlas arch rachischisis CT - partial anterior arch and os odontoideum , Hypertrophic anterior arch. Jefferson’s # (Irregular margins)

21. OS ODONTOIDEUM OSSICULUM TERMINALE Separate odontoid process Failure of fusion of base with body of axis Bergmann ossicle Failure of fusion of apical segment with base of dens os odontoideum with ossiculum terminale CONGENITAL ANOMALIES - AXIS

22. KLIPPEL FEIL SYNDROME CHIARI MALFORMATION Complex entity causing cervicovertebral fusion Associations- occipito-atlantoid fusion Low lying tonsils Associations- basiocciput hypoplasia , atlanto -occipital assimilation, platybasia CONGENITAL SYNDROMES Herniated tonsils, Acute clivocanal angle ,short clivus and cervical cord compression CT - violation of Chamberlain’s line , atlantooccipital fusion, atlantodens interval , fused C5-C8

23. Klippel Feil Syndrome Type 1: Elements of more than 2 cervical vertebrae are incorporated into single block. Type 2: Failure of complete segmentation at 1 or 2 Cervical levels. Type 3: Type 1&2 with failure of segmentation in lower dorsal & lumbar spine. Associated conditions: Scoliosis(60%), Genitourinary(65%), Sprengel’s Deformity(35%), Cardiopulmonary(15%), Deafness(30%). 20% cases may show facial asymmetry with Torticollis & Pterygium Colli .

24. Chiari Malformation Type 1: Caudal descent of cerebellar tonsils in cervical region. Presents in early adulthood. Associated with Syringomyelia in 50-70% of cases. Type 2: Caudal descent of cerebellar vermis & brain stem in cervical region. Type 3: Craniocervical Encephalocele containing portions of cerebellum & brain stem. Type 4: Caudal descent of cerebellum & brain stem upto mid cervical region.

25. Congenital Acquired Traumatic Atlantodens interval 3mm – adults, 5mm - children ATLANTOAXIAL DISLOCATION Dens fracture(irregular margins and atlantoaxial dislocation Rheumatoid arthritis with basilar impression, sclerosis of atlantoaxial joint and atlantoaxial dislocation TB, retropharyngeal collection, lytic area in dens and atlantoaxial dislocation INFECTIVE RHEUMATOID ARTHRITIS TRAUMA

26. Treatment F actors that influence the specific treatment of craniovertebral junction abnormalities are Reducibility of the bony lesion (ability to restore anatomic alignment, thereby relieving compression on neural structures) Mechanics of compression and direction of encroachment Cause of the pathologic process as well as the presence of hindbrain herniation, syrinx, and vascular abnormalities Presence of abnormal ossification centers and epiphyseal growth plates

27. Goals Relieve compression at the cervicomedullary junction. Stabilization in reducible lesions to maintain neural decompression. Irreducible lesions require decompression - ventral and dorsal compression states. Ventral decompression - operative approaches through a transpalatopharyngeal route, a LeFort drop-down maxillotomy , or a lateral extrapharyngeal route. In dorsal compression states - posterolateral decompression is required. If instability is present after decompression, posterior fixation is mandated for stability.

28. Grisel’s Syndrome I nflammatory, spontaneous subluxation that affects the atlantoaxial joints following parapharyngeal infection. Occur with conditions like tonsillitis, mastoiditis, retropharyngeal abscesses, and otitis media and most affects children younger than 12 years. Present with torticollis, neck pain, or neurological deficit. Mri - help identify parapharyngeal soft tissue masses, the presence of dislocation and osteomyelitis, or bone erosion. Needle biopsy of the prevertebral masses is essential to confirm the presence of a pyogenic focus and to obtain microbial specimens. Appropriate intravenous antibiotics must be administered Manual reduction of dislocation with cervical traction is reserved only for gross dislocations.

29. Down Syndrome Characteristic facial features , hypotonia, mental retardation, ligamentous laxity, and transverse palmar creases Identification of occipitoatlantal (O-C1) dislocation and atlantoaxial instability Increasing recognition of associated bony abnormalities such as os odontoideum , hypoplastic odontoid process, and rotary atlantoaxial luxation New-onset neurological deficits can occur in up to 1.2% of patients with down syndrome Surgical treatment - presence of neurological dysfunction, craniovertebral instability associated with a dystopic os odontoideum and/or incomplete atlantal arches, and sagittal plane excursion of more than 8 mm

30. Skeletal Dysplasias D ivided into five large categories: Osteochondral dysplasia Dysostosis Idiopathic osteolysis Chromosomal aberrations Primary metabolic abnormalities. The osteochondral dysplasias and dysostosis account for the largest and most complex entities

31. Osteochondral dysplasias Abnormalities of cartilage or bone growth in development. Includes achondrogenesis , thanatophoric dysplasia, chondrodysplasia punctata ( conradi-hünermann syndrome), achondroplasia, dystrophic dysplasia, metatrophic dysplasia, spondyloepiphyseal dysplasia, kniest’s dysplasia, cleidocranial dysplasia, and multiple epiphyseal dysplasias . Dysostoses - defined as malformations of individual bones singly or in combination. Includes crouzon’s , apert’s and carpenter’s syndromes with vertebral defects as well as sprengel’s deformity and klippel-feil syndrome. Idiopathic osteolysis - spondyloepiphyseal dysplasia tarda , fibrous dysplasia, neurofibromatosis, osteogenesis imperfecta, and multicentric forms such as hajdu-cheney syndrome

32. References 1. The craniovertebral junction – Diagnosis, Pathology, Surgical techniques by Atul goel , Fransesco 2. Surgery of the Craniovertebral Junction- Nicholas C. Bambakidis 3. Neurological surgery – 7 th edition, Chapter 233, Youmanns and Winn, Developmental Anomalies of the Craniovertebral Junction and Surgical Management , Arnold H. Menezes, Raheel Ahmed, and Brian J. Dlouhy

33. THANK YOU