Case contributed by Dr. Roy Waknin


A baby boy at 34 weeks gestational age was delivered via normal spontaneous vaginal delivery (NSVD). He presented with short limbs and desaturations.

Patient Data

Age: 0 days
Gender: Male

Radiographic imaging of the chest at birth

  1. An orogastric tube projects over the stomach.
  2. There is interstitial prominence throughout both lungs as well as a hazy opacification to both lungs. These findings are most consistent with both atelectasis and edema.
  3. Air is seen in the stomach and bowel.

Radiographic imaging of all extremities at 6 days old


The thorax is small and the abdomen appears protuberant. The vertebral bodies are diffusely mildly flattened and the interpedicular distance is decreased in the lumbar spine.

The iliac wings are flared superiorly and laterally, sacrosciatic notches are narrow and acetabular roofs are flat.

There is symmetric shortening of the humerus, radius, ulna, and the hand in the upper extremities, and of the femur, tibia, and fibula in the lower extremities. There is diffuse brachydactyly in both hands with cupping of the metaphysis of the metacarpals and phalangeal metaphyseal widening. There is diffuse fadeout of the proximal femurs and the metaphysis of the tibia and fibula in the lower extremities. There is diffuse metaphyseal flaring and widening in both upper and lower extremities.

Irregular appearance of the ossifications of the tarsal bones. There is diffuse increase in the number of skin folds in both upper and lower extremities consistent with achondroplasia. There is mild diffuse osteopenia mainly in the metaphysis most pronounced in the long bones.

No abnormal soft tissue calcifications.

Case Discussion

​This baby boy was born prematurely at 34 weeks gestation via normal spontaneous vaginal delivery (NSVD). He presented clinically with frontal bossing, mid-face hypoplasia, narrow and small thorax, protuberant abdomen, and short limbs.

In addition to the clinical presentation, the constellation of findings on radiographic imaging of the extremities and pelvis, including small thorax, decreased interpedicular distance in the lumbar spine, flared iliac wings, narrow sacrosciatic notches, flat acetabular roofs, rhizomeliamesomelia and acromelia, suggests the diagnosis of achondroplasia.

Other differentials include hypochondroplasia and spondylo-metaphyseal dysplasia, among others. Congenital syphilis is considered less likely.

The diagnosis of achondroplasia was later confirmed by genetic testing.


This case was submitted with supervision and input from:

Soni C. Chawla, M.D.                                                                                                
Associate Professor                                       
Department of Radiological Sciences                      
David Geffen School of medicine at UCLA               
Olive View-UCLA Medical Center

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