Skeletal Dysplasia Causing Short Limbs

Short limbs may be due to many causes. Dysplasia is a term that is used to denote abnormality in maturation of cells within a tissue. That means that the tissue developed would have abnormalities.

The skeletal development can be hampered by many causes and is classified according to the embryological segment affected.

Following types of skeletal dysplasias may cause short limbs

Rhizomelic Dysplasia

The proximal segment of the limbs is affected. It can be due to

Hypochondroplasia

It resembles a mild form of achondroplasia.

Achondroplasia

Achondroplasia is a common cause of dwarfism. It occurs as a sporadic mutation in approximately 80% of cases or it may be inherited as an autosomal dominant genetic disorder.

Chondrodysplasia Punctata

Chondrodysplasia punctata has both autosomal dominant and  autosomal recessive types. Recessive type is rare.

In autosomal dominant type (Conradi-Hunerman), in the newborn stippling is evident in the long bone epiphyses, spine and larynx. There could be  malsegmentation of  vertebral bodies. Stippling disappears by 2 years of age and there is asymmetrical shortening of limbs.

These patients usually survive into adulthood.

Autosomal recessive  type is marked symmetrical rhizomelia with humeri more severely affected than femora. Spinal stippling is mild. Stillborn or perinatal death.

Pseudoachondroplasia

This is marked by short limb and short spine, marked joint laxity, platyspondyly with exaggerated grooves for the ring apophyses and C1-C2 dislocation.

Mesomelic Dysplasia

This involves shortening in the middle segment.

Dyschondrosteosis

Also known as Leri-Weil disease this is manifested as limb shortening with a Madelung deformity.

Langeresomelic type  dysplasia

Reinhardt-Pfeiffer type Dysplasia

Acromesomelic

This involves middle and distal segment limb shortening

Chondroectodermal dysplasia

It is also known as Ellis-van Creveld syndrome and is  similar to asphyxiating thoracic dysplasia (see below) but  with these differences

• Hexadactyly is a constant finding
• There is severe hypoplasia of the fingers and nails
• Congenital heart disease is common and
• Hypoplastic lateral tibial plateau is characteristic

Acromesomelic dysplasia

• Nievergelt type
• Robinow type
• Werner type

Acromelic

This involves distal segment shortening

Asphyxiating thoracic dysplasia or Jeune’s syndrome

This is hallmarked by narrow thorax with short ribs leading to respiratory distress. Spur-like projections of the acetabular roof can be found. Premature ossification of the femoral capital epiphyses may occur.  Occasional post-axial hexadactyly and cone-shaped  epiphyses may occur  in childhood.

Peripheral Dysostosis