Type II Osteogenesis Imperfecta
(Lethal Form)

  1. A normal ultrasound at 17 weeks of gestation excludes the diagnosis.
  2. Subjective demineralization of fetal bones.

        Note the exquisite visualization of the near field choroid plexus in the fetus with absent cranial ossification.

3.      Femora >3SD below the expected mean  femoral length for that gestational age                            (severe micromelia).

4.      Bones are short and broad.

 

 

Small thick, bowed femur

 

  1. Multiple fractures in a single bone:
    1. Wrinkled appearance to the bone.
    2. Discontinuity of the bone.
    3. Thick callous

 

 

 

 

 

Radius + ulna (3D)

 

 

 

 

Tibia + fibula (3D)

 

Tibial fracture (2D and 3D)

 

Humerus – micromelia + acute angulation due to fracture
  1. Ribs:
    1. Thin and beaded.
    2. ± Fractures.
    3. Concave thorax.

 

 

 

  1. Thorax:
    1. Thoracic circumference below 2.5th percentile.
    2. Bell shaped chest (concave thorax and protuberant abdomen).

 

 

 

 
  1. Calvarium:
    1. Thin.
    2. Echopenic due to non-mineralization.
    3. Abnormal compressibility (may therefore get varying cranial biometry).
    4. Exquisitely clear visualization of intracranial contents due to the lack of near field reverberation).

 

14 wks

34 wks

 

 

 

 

 

 

 

 

9.      Pseudotalipes – due to the bowing and                                  fractures.

 

 

 

10.  Spine:

a.      Platyspondyly.

b.      Normal ossification.

 

 

  1. Other features:
    1. Wormian bones in the skull.
    2. Metaphyseal flaring.
    3. Platyspondyly.
    4. Polyhydramnios.

 

 

 

 

3D post mortem CT scan

 

 

Plain Films

 

Coronal CT images

 

 

 

Cranium

 

Pelvic Girdle

 

Spine (left)

Upper limbs (right)

 

Thoracic Cavity

 

 

 

 

Video clip of Osteogenesis Imperfecta type II

 

 

DIFFERENTIAL DIAGNOSIS OF LETHAL FORMS
  1. Congenital Hypophosphatasia
  2. Achondrogenesis Type I
  3. Achondrogenesis Type II

 

DIFFERENTIAL DIAGNOSIS OF NON - LETHAL FORMS
  1. Campomelic dysplasia