Congenital Dz Flashcards
Three categories of congenital disorders
Congenital anomalies
Normal skeletal variants
Skeletal dysplasias
______ are the result of faulty development and can grouped according to the features of the disease:
Proximal or distal limb shortening
Sclerosis of osseous structures
Specific spinal abnormalities
Agenesis or duplication of specific anatomic structures
Skeletal dysplasias
Congenital stenosis of spinal canal and foramen magnum
Prone to hydrocephalus
Altered biomechanics for early DJD (fibular head at level of tibial plateau)
Decreased acetabular angle (FAI?)
Achondroplasia
Multiple enostomas about the skeleton…largely about joints
“dont touch me” lesion
Osteopoikilosis
A “block vertebrae” = a lack of segmentation and separation of the craniovertebral junction
May be partial or complete
Radiographs:
Decreased or absent space between posterior arch of C1 and occiput
Occipitalization of the atlas
May cause compression of the medulla oblongata and spinal cord by the dens protruding through the foramen magnum
May be associated with other conditions, e.g., Arnold-Chiari malformation, atlantoaxial instability, Klippel-Feil syndrome
MRI – valuable to detect any associated neural or vascular anomalies
Occipitalization of the atlas
Easily seen on lateral radiographs as a lack of a bony posterior neural arch
Commonly also see enlargement of the C2 spinous process, aka “mega-spinous process”
May also see increased size or density of the C1 anterior tubercle (stress related)
Agenesis of the C1 posterior arch
May have compromise of the transverse ligament; need flexion lateral view
Calcification/ossification of the atlanto-occipital ligament
May be partial or complete, forming an arcuate foramen
Unilateral (m/c) or bilateral
Posterior ponticle
A smooth, wide, lucent defect separates the odontoid process from the C2 body
Stress hypertrophy of the anterior tubercle of C1
Os odontoideum
_______ + high-velocity injury can produce central cord syndrome or fatal injury
May have atlantoaxial instability, or compression of the vertebral artery from stretching of the artery during C1 subluxation
Need flexion/extension lateral views; maybe also MRI
Os odontoideum
Failure of segmentation
Body +/- posterior elements
Radiographic features:
Diminished AP diameter of the vertebral body
Concave anterior margins of the vertebrae, aka “wasp waist”
Hypoplastic/rudimentary disc space
Block vertebrae
Triad of short, webbed neck, low hairline, and decreased C/S range of motion (multiple block vertebrae)
May also include scoliosis or Sprengle’s deformity
Includes genitourinary, nervous and cardiopulmonary anomalies
Klippel-Feil syndrome
An anomalous rib that forms a joint with a transverse process that is oriented in a caudal direction (cervical)
Variable length
No clinical significance
Cervical rib
Failure of the lateral ossification centers to unite
On the AP view there is an hourglass central lucency with indentation of the endplate cortices toward the central body and slight increase in the interpediculate distance
The halves are usually symmetrical; therefore, scoliosis is not associated
Butterfly vertebrae
T/S and L/S
Failure of one of the lateral ossification centers to grow
Results in a triangular deformity of the body with the endplates tapering to a point
An isolated ______ will cause a structural scoliosis, the _______ at the apex of the curve
Usually associated with other spinal anomalies
Hemivertebra
Failure of development of the ossification center for a neural arch
Oblique projections will demonstrate the dysplastic osseous structures, with smooth margins
Hypertrophy of the contralateral pedicle may be present (a hallmark of congenital origin)
Agenesis of a lumbar pedicle
Must be differentiated from tumor destruction (neurofibromatosis, aneurysm or mets)
Agenesis of a lumbar pedicle
Also occurs in the C/S (absent spinolaminar line) and sacrum
A defect in the laminae where they would meet to form the spinous process (“a defect in the posterior neural arch” or “cleft spinous”)
No clinical significance
Spina bifida occulta
Occur at the cervicothoracic, thoracolumbar and lumbosacral junctions
The vertebrae demonstrate features of both adjacent spinal segments
m/c at the lumbosacral junction
Variable presentations
At the lumbosacral junction, those that form pseudo-articulations may be symptomatic
Transitional segments
Elongated spinous process of L5
SBO at S1
Significance:
May cause pain/symptoms with extension
Clasp Knife syndrome
Pectus ______ (Look for straight back syndrome)
excavatum
Rib anomalies
Srb’s anomaly
Fusion of other ribs
Bifurcated ribs
Congenital displacement of the femoral head due to a malformed acetabular cup
Absent or small epiphysis, lateral displacement of the femur, increased inclination of the acetabular roof (shallow acetabulum), malformed femoral head
If remains displaced, may form a pseudoarticulation
Developmental dysplasia of the hip (DDH)
Which hip is more commonly affected in Developmental dysplasia of the hip (DDH)
L
