Achondroplasia (chondrodystrophy) is a hereditary cartilage disorder, likely inherited in a dominant manner. It primarily involves impaired cartilage cell formation at the metaphyses of long bones, leading to hindered endochondral ossification and affecting bone length; subperiosteal ossification remains unaffected, allowing bone width to continue increasing. This results in shortened limb deformities. Concurrently, premature ossification of cranial cartilage causes a shortened skull base, with upward expansion of the skull and a broad, prominent forehead. Most affected individuals die during fetal or neonatal stages, while survivors typically have a normal lifespan.

bubble_chart Clinical Manifestations

The limbs are thick and short, with stubby and evenly aligned fingers, and the lower limbs often curve inward. The torso is relatively long, with a protruding lumbar spine and a posteriorly protruding buttocks. The head is large, with a prominent forehead, a flat nasal bridge, and a protruding chin. Dwarfism is evident at birth.

bubble_chart Auxiliary Examination

X-ray films show that the long bones of the limbs are short and thick, with increased curvature, widened metaphyses, and grade I irregularities.

bubble_chart Treatment Measures

There is no specific treatment. The main approach is to enhance protection and avoid fractures.

bubble_chart Differentiation

It should be differentiated from congenital osteogenesis imperfecta.