Scoliosis Research Society (SRS)
Scoliosis Research Society (SRS)
An International Organization Dedicated to the Education, Research and Treatment of Spinal Deformity
Our Mission is to Foster Optimal Care for All Patients with Spinal Deformities

What is Kyphosis?

Congenital kyphosis at the junction of the thoracic and lumbar spine.
Figure 1: Congenital kyphosis
at the junction of the thoracic
and lumbar spine.
Definition and Classification
In the first six to eight weeks of embryonic life, a genetic mistake occurs that results in the failure of formation or failure of segmentation on the front part of one or more vertebral bodies and disc. This defect causes the spine to develop a sharp forward angulation as it grows. The forward bend of the spine is called kyphosis and is considered to be congenital as it occurred prior to birth. Congenital kyphosis does not appear to be inherited but rather something that happened for no known reason.

There are two basic types of congenital kyphosis: failure of formation and failure of segmentation. The failure of formation (Type I deformity) of a portion of one or more vertebral bodies most often occurring in the thoracolumbar spine, results in a kyphosis that usually worsens with growth (Figure 1). The deformity is usually visible at birth as a lump or bump on the infant's spine. The failure of segmentation deformity (Type II deformity) occurs as two or more vertebrae fail to separate and to form normal discs and rectangular bones. This type of congenital kyphosis is often more likely to be diagnosed later, after the child is walking.

Congenital Scoliosis
Early Onset Scoliosis
About Early Onset Scoliosis
Infantile Idiopathic Scoliosis
Thoracic Insufficiency Syndrome
Juvenile Idiopathic Scoliosis
Idiopathic Scoliosis