Congenital Dz

Question 1

Three categories of congenital disorders

Answer 1

Congenital anomalies
Normal skeletal variants
Skeletal dysplasias

Question 2

______ 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

Answer 2

Skeletal dysplasias

Question 3

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?)

Answer 3

Achondroplasia

Question 4

Multiple enostomas about the skeleton…largely about joints

“dont touch me” lesion

Answer 4

Osteopoikilosis

Question 5

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

Answer 5

Occipitalization of the atlas

Question 6

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

Answer 6

Occipitalization of the atlas

Question 7

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)

Answer 7

Agenesis of the C1 posterior arch

May have compromise of the transverse ligament; need flexion lateral view

Question 8

Calcification/ossification of the atlanto-occipital ligament
May be partial or complete, forming an arcuate foramen
Unilateral (m/c) or bilateral

Answer 8

Posterior ponticle

Question 9

A smooth, wide, lucent defect separates the odontoid process from the C2 body
Stress hypertrophy of the anterior tubercle of C1

Answer 9

Os odontoideum

Question 10

_______ + 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

Answer 10

Os odontoideum

Question 11

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

Answer 11

Block vertebrae

Question 12

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

Answer 12

Klippel-Feil syndrome

Question 13

An anomalous rib that forms a joint with a transverse process that is oriented in a caudal direction (cervical)
Variable length
No clinical significance

Answer 13

Cervical rib

Question 14

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

Answer 14

Butterfly vertebrae

T/S and L/S

Question 15

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

Answer 15

Hemivertebra

Question 16

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)

Answer 16

Agenesis of a lumbar pedicle

Question 17

Must be differentiated from tumor destruction (neurofibromatosis, aneurysm or mets)

Answer 17

Agenesis of a lumbar pedicle

Question 18

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

Answer 18

Spina bifida occulta

Question 19

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

Answer 19

Transitional segments

Question 20

Elongated spinous process of L5
SBO at S1
Significance:
May cause pain/symptoms with extension

Answer 20

Clasp Knife syndrome

Question 21

Pectus ______ (Look for straight back syndrome)

Answer 21

excavatum

Question 22

Rib anomalies

Answer 22

Srb’s anomaly
Fusion of other ribs
Bifurcated ribs

Question 23

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

Answer 23

Developmental dysplasia of the hip (DDH)

Question 24

Which hip is more commonly affected in Developmental dysplasia of the hip (DDH)

Answer 24

L

Question 25

Knee:

Superolateral aspect, smooth and corticated margins

Answer 25

Bipartite patella

Question 26

Fibrous or bony union between two or more tarsal bones

Biomechanically induced osteoarthritis

Answer 26

Tarsal coalition

Question 27

Humeral exostosis which points towards the adjacent joint

May be subject to fracture or may compress the median nerve

Answer 27

Supracondylar process

Question 28

Distal ulna is shorter than distal radius

Increased potential for Kienbock’s disease (AVN of the lunate)

Answer 28

Negative ulnar variance

Question 29

Increased potential for TFCC tears/ulnar abutment syndrome

Answer 29

Positive ulnar variance

Question 30

Fusion of two or more carpal bones

May also be secondary to disease (RA, septic arthritis)

Answer 30

Carpal coalition

Question 31

Increase # of fingers or toes

Answer 31

Polydactyly

Question 32

Fusion of the skin between the digits or fusion of the osseous phalanges

Answer 32

Syndactyly