Congenital- Achondroplasia

Question 1

Def.

Answer 1

• Most common congenital dwarfism.

* Genetic -> autosomal dominant transmission.

Question 2

Radiol Fx.

Answer 2

• generalized defect in enchondral bone formation, leading to under development of the portions of the bone that grow by this mechanism.
• result = short limbed dwarfism in which proximal segments of the extremities are disproportionately short.
• Periosteal bone growth in long bones 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.