Skeletal Dysplasias Flashcards
Skeletal dysplasias. Broad definition
- aka osteochondrodysplasia -
- any abnormality in bone formation. -
- very wide clinicopathological spectrum. -
- ~2/10000 live births -
- 32 groups -
- more than 350 distinct entities -
- broadclassification
- Limb deficiencies
- amelia: complete limb abscence
- meromelia: partial limb absence
- Limb shortening
- Rhizomelic Dqarfism
- limb shortening, most notable proximally
- achondroplasia (most common short-limbed dwarfism)
- Thanatophoric Dysplasia
- Osteogenesis imperfecta
- rhizomelic chrondrodysplasia punctata
- asphyxiating thoracic dysplasia (jeune disease)
- Atelosteogenesis.
- limb shortening, most notable proximally
- Non-rhizomelic
- non-rhizomelic chondrodysplasia punctata
- distrophic dysplasia
- campomelic dysplasia
- Chrondroectodermal dysplasia/ellis van creveld syndrome
- Kniest dysplasia
- Achondrogenesis
- type 1
- Type 2
- Spondyloepiphyseal dysplasia
- Multiple epiphyseal dysplasia
- hypochondroplasia
- metaphyseal chorndrodysplasia
- Non-limb shortening
- pyle disease
- progressive diaphyseal dysplasia
- Limb deficiencies
Thanatophoric Dysplasia
- lethal skeletal dysplasia.
- MOst common letha skeletal dysplasia followed by osteogenesis imperfecta type II.
- 1-25000
- mutation coding for the fibroblast growth rewceptor 3, located on chromosome 4 p 16.3. Sporadic inheritance.
- Subtypes
- type
Cleidocranial dysostosis
brachycephaly + wormian bones + absent clavicles
Abstract
Cleidocranial dysplasia:
AD skeletal dysplasia
abnormal clavicles,
patent sutures and fontanelles,
supernumerary teeth,
short stature,
and a variety of other skeletal changes.
The disease gene has been mapped to chromosome 6p21 within a region containing CBFA1, a member of the runt family of transcription factors.
Typical clinical and radiological findings in CCD. (A) Facial appearance in a 6 month old boy. Note large, brachycephalic skull, frontal and parietal bossing with large anterior fonanelle, and the appearance of a small face. Other characteristic features include widely spaced eyes, low nasal bridge, reduced nasal length, but increased nasal width and protrusion. (B) Chest radiograph showing cone shaped thorax and left clavicular hypoplasia and aplasia on the right side. (C) Pelvic abnormalities in a 4 year old girl. Note hypoplasia of the iliac wings, broad femoral necks with large epiphyses, and unossified symphysis pubis. (D) Hand radiograph of a 2½ year old female showing hypoplastic distal phalanges, accessory epiphyses of the second metacarpal, and long second metacarpal. (E) Pantomographic view of the permanent dentition of a 16 year old female. Note multiple, unerupted, supernumerary teeth.
https: //jmg.bmj.com/content/36/3/177
https: //jmg.bmj.com/content/36/3/177
Definition of Bone dysplasias
Impairment of normal growth of bone, yielding an abnormal skeleton. The impairment can involve growth slowing down, speeding up or can cause bones to grow in an unusual manner
Rhizomelia
Proximal limb shortening
(ie humerus too short)
Mesomelia
Middle limb shortening
ie radius too short
Acromelia
distal limb shortening
hand or wrist is too short
Micromelia
Entire limb is shortened
Amelia
limb is absent
What are the key findings of Achondroplasia
- Most common cause of dwarfism. normal IQ.
- Key findings:
- Spine,
- there is caudal narrowing of the interpediculate distance
- posterior vertebral scalloping
- thoracolumbar kyphosis
- increased lumbosacral angle
- Chest
- anterior flaring of ribs.
- Pelvis,
- the sacroiliac groove is notch-like,
- the acetabular angles are decreased,
- the iliac wings are small and square (tombstone-shaped),
- and the pelvic inlet is shaped like a champagne glass.
- Limbs:
- There is metaphyseal flaring
- The epiphyseal ossification centers show a circumflex or chevron seat on the metaphysis
- The proximal limbs are strikingly short (rhizomelic shortening)
- hands have short phalanges and a
- trident-hand appearance
- The fibulae are relatively long
What are the key findings?
What condition is this?
Figure 7a. Achondroplasia in a 3-year-old boy with short stature. (a) Frontal radiograph of the abdomen and pelvis shows caudal narrowing of the interpediculate distance in the lumbar spine (white arrows), square iliac wings, and narrow sciatic notches (black arrows).
https://pubs.rsna.org/doi/full/10.1148/rg.2017170017
What are the key findings?
What condition is this?
Figure 7b. Achondroplasia in a 3-year-old boy with short stature.
(b) Frontal radiograph of the lower extremities shows shortening of the tubular bones with metaphyseal widening (arrows).
https: //pubs.rsna.org/doi/full/10.1148/rg.2017170017
What are the key findings?
What is the condition?
Figure 7c. Achondroplasia in a 3-year-old boy with short stature. (c) Lateral radiograph of the lumbar spine shows mild kyphosis at the thoracolumbar junction, posterior scalloping of vertebral bodies (arrow), and bullet-shaped L1 and L2 vertebral bodies.
What are the key findings?
What is the condition?
Trident hand
(d) Frontal radiograph of the right upper extremity shows short tubular long bones with metaphyseal widening and trident hand (arrow).
Figure 7d. Achondroplasia in a 3-year-old boy with short stature.
https://pubs.rsna.org/doi/full/10.1148/rg.2017170017
What are the key findings?
What is the condition?
Figure 7e. Achondroplasia in a 3-year-old boy with short stature.
Lateral radiograph of the skull shows frontal bossing and an increased craniofacial ratio with a small skull base.
What are the key findings?
What is the condition?
Figure 8a. Achondroplasia in a 5-month-old girl. (a) Sagittal T2-weighted MR image shows a narrowed foramen magnum and compressed cervicomedullary junction (arrow). (b) Axial T2-weighted MR image shows the resultant mild ventriculomegaly and prominent subarachnoid spaces in both frontal regions (arrows).
What are the key findings?
What is the condition?
Pfeiffer syndrome
Craniosynostosis
- Fusion of the coronal sutures
- Broad Thumbs
- Ankylosis of the elbows (Type 2/3)
- Midface hypoplasia
- Medialised Great toes
- Partial syndactyly of the digits
- broad medially deviated thumbs
