Sclerosing dysplasias - finished

Question 1

What is ostepetrosis

Answer 1

Hereditary condition, no resorption of normal primitive osteochondroid tissue; osteoclasts may not respond to parathyroid hormone; primitive calcified cartilage persists (does not OSSIFY)

This results in inhibition of medullary canal formation; absence of marrow, anaemia and extra medullary haematopoiesis

Often see vertical or horizontal striations of normal bone area interspersed with the predominant primitive tissue

Question 2

What are the clinical features of osteopetrosis

Answer 2

Hepato and splenomegaly
Severe anaemia
Lymphadenopathy
Thrombocytopaenia
Malaise
Brittle dense bones that fracture easily (transverse #)
Bones heal quickly with callus of defective osteopetrotic bone

Question 3

What are the radiographic findings of ostepetrosis?

Answer 3

Generalised skeletal sclerosis. Homogenous increased density, absence of trabeculation, absence of medullary canal.
Bone within a bone appearance or endobones.
Flared elongated metaphyses on long bones
In the spine see uniformly dense vertebrae or sandwich vertebrae with dense bone adjacent to endplates and normal centra.

Question 4

Define osteopoikilosis

Answer 4

Autosomal dominant condition
Seems to be remodelling of spongy bone caused by mechanical stresses
Lesions may be small foci that fail to become cancellous
They are compact lamellar bone with Haversian systems, like bone islands, but they are not usually metabolically active

Question 5

What are the clinical features of osteopoikilosis

Answer 5

Rarely found before age 3
25% have cutaenous abnomalities (dermatofibrosis, keloid formation etc)
20% have mild joint pain and may have joint effusion

Question 6

What are the radiographic findings of osteopoikilosis?

Answer 6

Juxtaarticular small round or ovoid radio-opacities (pathognomonic)
Epiphyseal and metaphyseal regions affected
Symmetric involvement: predilection for long bones, carpals and tarsals
Occurs: ilium, scapula, glenoid
Rarely in skull, spine, ribs or clavicle

Question 7

What is Melorheostosis?

Answer 7

Appears to be congenital

Slow progression and usually monomelic (more commonly lower limb)
Lesions appear to follow sclerotomes and myotomes supplied by a single spinal sensory nerve

Question 8

What is the proper name for dwarfism?

Answer 8

Congenital achondroplasia

Question 9

What are the common radiographic findings for dwarfism?

Answer 9

Results in generalized defect in enchondral bone formation, leading to under development of the portions of the bone that grow by this mechanism.

Periosteal bone growth in unaffected (shafts of long bones normal diameter).

Lx: hyperlordotic, short thickened lx. Pedicles with decreased inter-pedicle distance.
Vertebrae: Bullet nose appearance with posteriorly scalloped vertebral bodies.
Can see short ribs, characteristic trident hand, widely spaced third and fourth digits.

Mushroom cap femoral head or Coxa magna
Large lesser trochanter

Question 10

What are the percentages of cerebral palsy occurrence pre, during and post birth?

Answer 10

70% brain damage occurs prior to birth (mostly in the second and third trimester).

20% occurs during the birthing period

10% occurs during the first two years of life while the brain is still forming.

Question 11

What are some causes of cerebral palsy

Answer 11

Some causes of congenital Cerebral Palsy include

• oxygen deprivation
• complex pregnancies
• medical malpractice
• growth restriction
• sexually transmitted disease
• birth positioning
• placental complications

Question 12

What are the 4 main types and brief description of each of the types of CP

Answer 12

Cerebral dysgenesis: Abnormal brain development usually within 1st 20 weeks of gestation.

Hypoxic-Ischemic Encephalopathy (HIE), also known as Intrapartum Asphyxia: Caused by oxygen deprivation to the brain.

Intraventricular Haemorrhage, or IVH: Severity of impairment is dependent upon the location and degree of damage. The haemorrhage can be arterial or venous

Periventricular Leukomalacia, or PVL: Type of brain damage that involves the periventricular white matter of the brain. Damage to the white matter results in the death and decay of injured cells, leaving empty areas in the brain — called lateral ventricles, which fill with fluid (a condition called leukomalacia).

Question 13

Major radiographic findings of CP

Answer 13

When the normal skeleton remodels in response to abnormal stress, dysplastic changes in the bones and joints may result.

Long bones often appear overtubulated (narrow shaft, broad epiphysis).
Hip dysplasia secondary to chronic, spastic dislocation is common.
Scoliosis, soft tissue atrophy and flexion/extension contractures may be found.

Question 14

How does a congenital scoliosis occur?

Answer 14

Congenital scoliosis: Failure of formation of individual vertebrae.

During the embryonic conversion of mesenchymal vertebrae to cartilaginous vertebrae before week 9 of development, each vertebral body becomes chondrified from 2 centers of chondrification on either side of the midline.
- If chondrification fails on only one side, isolated hemivertebrae results.
- If the centres of chondrification do not fuse at the same level (as they should), but fuse across levels instead, a trapezoidal vertebrae results. Each side of the neural arch has its own centre of chondrification and similar failures of development or abnormal fusion will result in anomalies.
The most common vertebral anomalies causing congenital scoliosis include hemivertebrae, trapezoidal vertebrae, and unilateral neural arch fusion.