· syn. congenital synostosis of cervical vertebrae
· KF refers to patients with any element of cervical fusion
· classic triad is
· short neck
· low posterior hairline
· limitation of neck movement
· triad present in <50%
· failure of normal segmentation of mesodermal somites of neck
· during 3rd to 8th week
· may be autosomal dominant inheritance
· limitation of neck movement
· esp. laterally
· usually hypermobility in unaffected levels
· short neck
· head arises from shoulders
· often associated with webbing of neck
· low posterior hairline
· on level with shoulders
· most of orthopaedic problems caused by hypermobility
· leads to instability and degenerative osteoarthritis
Scoliosis
· in 60%
· of congenital type
· associated respiratory problems
· need to consider neck prooblems when scoliosis treated
Sprengel’s deformity
· in 30%
· same insult that causes KF halts descent of scapulae
Renal
· in 35%
· renal failure often occurs early
Deafness
· in 30%
· affects development of speech and language
Synkinesia
· in 20%
· involuntary paired movements of hands
· abnormality of pyramidal tracts
· usually resolves
Cardiac
· in 15%
· various congenital defects
· important in preoperative planning
· plain x-ray
· tomography
· CT scan
· fusion of vertebral bodies
· hemivertebrae
· flattening and widening of vertebral bodies
· hypoplasia of discs
· cervical spina bifida
· thoracic abnormalities
· scoliosis
· kyphosis
· primarily of associated conditions
· torticollis
· scoliosis
· webbing
· little can be done for neck deformity
· should be advised to avoid contact sports
· means twisted neck
· associated with
· CDH
· breech presentation
· Klippel-Feil syndrome
· fibrosis of sternomastoid muscle on one side
· fails to grow and causes progressive deformity
· unknown
· may be
· ischaemia from distorted position in utero
· birth injury
· lump may be noticed in 1st few weeks of life
· usually disappears
· deformity becomes apparent at age 1-2 yrs
· head tilted to one side so ear approaches shoulder
· may be associated facial hemiatrophy
· bony anomaly
· trauma
· discitis
· lymphadenitis
· if diagnosed in infancy
· preventative stretching
· for established deformity
· contracted muscle divided
· head maintaned in corrected postion with collar
Os odontoideum
· failure of fusion of base of odontoid
· appears like type II odontoid fracture
Odontoid hypoplasia
· congenitally small odontoid
Odontoid aplasia
· absence of odontoid
Congenital
· odontoid formed from 1st cervical sclerotome
· corresponds to original centrum of C1
· separates from C1 and fuses to C2
· tip of odontoid formed from most caudal occipital sclerotome
· called pro-atlas
· body of odontoid fuses by birth
· from two centres
· tip of odontoid not ossified at birth
· tip of odontoid often V-shaped notch
· tip of odontoid
· ossifies by age 3 yrs (ossiculum terminale)
· fuses by age 12 yrs
· called ossicum terminale persistens if fails to fuse
· physis at base of odontoid
· present at birth
· lies below level of superior articular facets of axis
· fuses by age 6
· deformities may be
· os odontoideum (failure of fusion of tip)
· hypoplasia (absence of tip)
· aplasia (absence of odontoid)
Developmental
· may be traumatic event
· usually asymptomatic
· may present in adulthood with
1. pain
· usually dull ache
2. neurological symptoms
· L’emitte sign
· long tract signs
· risk of sudden death
· seen on open-mouth view
· as described above
· measured on lateral flexion-extension views
· instability if
· > 3 mm translation on flexion-extension views
· atlanto-dens interval > 5 mm
· posterior C1-2 fusion
· Gallie technique
Definition
· AP subluxation of C1-C2
Aetiology
Primary
· due to laxity of transverse ligament
· common in Down’s syndrome (15%)
· also seen in
· Morquio syndrome
· Larsen syndrome
· achondroplasia
· spondyloepiphyseal dysplasia
· secondary
· os odontoideum
· trauma
· rheumatoid arthritis
Clinical
· usually asymptomatic
Radiology
· instability defined as atlanto-dens interval > 5 mm
· usually symptomatic if ADI > 7 mm
Treatment
· avoid contact sports
· stabilise surgically if
· symptoms of instability
· neurological problems
· ADI > 10 mm
Definition
· rotatory subluxation of C1-C2
Aetiology
· ligamentous laxity secondary to
· retropharyngeal abscess (Grisel’s syndrome)
· trauma
· Down’s syndrome
Clinical
· neck stiffness and discomfort
· cock-robin defomity
· head tilted to one side and rotated to opposite side
Radiology
· asymmetry of lateral masses of atlas
· lateral mass that has shifted forwards smaller and further away from midline
· CT scan useful
Treatment
Nonoperative
· may resolve spontaneously
· usually corrected with traction and then collar
Operative
· surgery indicated for
· neglected fixed deformity
· neurological deficit
· anterior displacement
· failure to correct with conservative means
· in form of C1-2 fusion
· cranial prominence of odontoid into region of foramen magnum
· congenital
· acquired
· juvenile rheumatoid arthritis
· rickets
· upper cervical spine encroaches on brain stem
Symptoms
· of neurological compression
· lightning pain
· sensory loss
· weakness
Signs
· dysmorphic features
· short neck
· low hairline
· neurological deficit
· motor
· sensory
· McGregor’s line
· from upper surface of posterior ridge of hard palate
· to most caudal point of occipital curve
· odontoid should be no more than 4-5 mm above line
· consider surgery if symptomatic
· surgery complex and fraught with complications
· occipitocervical fusion
· excision of odontoid
· subluxation in children up to age 8
· usually of C2 on C3
· may be of C3 on C4
· up to 4 mm or 40%
normal because of orientation of facets