Scheuermann's Disease & Juvenile Disc Disease

Scheuermann's disease is a rigid, structural kyphosis of the thoracic or thoracolumbar spine that develops during adolescent growth.

It is defined radiographically by anterior wedging of 5° or more in 3 or more consecutive vertebrae (Sorensen's criteria). It typically presents between 12 and 17 years, is slightly more common in boys and often runs in families. It must be told apart from postural kyphosis, which is flexible and corrects on active extension.

Juvenile disc disease is disc herniation or degeneration under 18, usually lumbar and often in heavy-loading sports such as gymnastics, weightlifting, rowing and fast bowling. Most adolescents with non-specific back pain do not need routine imaging.

The vertebral endplate is the cartilaginous growth zone between the vertebral body and the disc. In adolescence it is incompletely ossified and is the weak link in both conditions; in adults the annulus usually fails first.

Scheuermann's disease:

• •A disorder of endplate growth and ossification reduces anterior vertebral body growth, producing wedging and a structural kyphosis. Mechanical loading during growth and genetic susceptibility both appear to contribute.
• •Schmorl's nodes (disc herniating through the endplate into the vertebral body), endplate irregularity and disc space narrowing are supportive features.
• •Classic thoracic form: apex usually mid-thoracic, often a cosmetic concern and may be painless.
• •Atypical thoracolumbar or lumbar form: more often painful and associated with repetitive axial loading.

Juvenile disc disease:

• •The ring apophysis (the ossification centre at the vertebral rim) is not yet fused. Under axial load in flexion, disc material can avulse a posterior fragment into the canal (a posterior limbus fracture), usually at L4/5 or L5/S1.
• •A bony fragment does not resorb as soft disc material can.
• •Risk factors: heavy-loading sport, sudden spikes in training load and a family history.