Scheuermann's disease

Synonyms: juvenile kyphosis, Scheuermann's kyphosis, juvenile discogenic disease

What is Scheuermann's disease?

Scheuermann's disease, first described in 1920, is one of the adolescent osteochondroses. It is essentially osteochondrosis of the thoracic vertebral bodies which leads to wedge-shaped vertebrae.¹It involves both the vertebrae and the discs.² It causes increased kyphosis, poor posture and backache. It is the most common cause of structural kyphosis in adolescents.^{3 4}

There is a separate article giving an overview of Osteochondroses.

Pathophysiology

• Osteochondroses all involve a defect in ossification. In Scheuermann's disease there is a defect in the secondary ossification centres of the vertebral bodies. A few vertebral bodies may be involved or the whole thoracolumbar spine.

• Type 1 Scheuermann's disease is where the thoracic spine only is affected; in type 2 Scheuermann's disease both the thoracic and lumbar spine is affected.

• The cause is unknown but hereditary factors are thought to play a part in the pathophysiology. However, no definite mode of inheritance or genetic marker has been established so far.⁵ It is thought that there is a genetic factor which results in discordant vertebral endplate mineralisation and ossification during growth, causing disproportional vertebral body growth with the resultant classic wedge-shaped vertebral bodies that lead to kyphosis.²

• Other factors include a correlation between Scheuermann's disease and taller height, as well as an association with higher BMI and increased levels of growth hormone.⁶ One study has suggested that the increased weight and height in those with Scheuermann's disease are not part of the pathogenetic mechanism, but suggests that these are secondary effects.⁷

• Mechanical factors and trauma have also been cited as possible causes; the aetiology is probably multi-factorial.

How common is Scheuermann's disease? (Epidemiology)²

• Usually presents in adolescents aged between 12 and 17 years. It is rare in younger children.

• The incidence is variously reported between 0.4% and 8%.

• Most studies suggest it is at least twice as common in males than females.

Symptoms of Scheuermann's disease (presentation)⁶

History

• Poor posture with increased kyphosis (usually noticed by parents).

• Dull, non-radiating pain around the apex of the kyphosis.

• The pain tends to be worse with activity and improve with rest.²

• Neurological symptoms are rarely the presenting feature but there is an increased risk of disc degeneration and cord compression with age.

Examination

• It is normal to have a degree of kyphosis. Any degree of kyphosis of more than 50° is considered abnormal.⁸

• Kyphotic deformity may be progressive.

• Upper thoracic kyphosis is best seen in the forward flexed position; lower thoracic kyphosis may be seen at the thoracolumbar junction.

• There is reduced flexibility of the spine.

• There may be tenderness above and below the apex of the kyphosis.

• A third of patients will also have a mild scoliosis, spondylolysis of L5 or lumbosacral spondylolisthesis.

• You should carry out a neurological examination but neurological signs are rare.

Differential diagnosis

Includes:

• Postural kyphosis (known as postural round back deformity; kyphosis is flexible).

• Ankylosing spondylitis.

• Glucocorticoid-induced osteoporosis in Cushing's syndrome, which can lead to thoracic kyphosis.

• Skeletal dysplasia.

• Congenital kyphosis (failure of segmentation).

• Spinal tuberculosis (consider if there is atypical presentation).

Diagnosing Scheuermann's disease (investigations)

• X-ray of the spine is required for diagnosis of Sheuermann's disease, as it is defined by the appearance of hyperkyphosis of at least 40^o2 and 'wedge-shaped vertebral bodies with anterior wedging of at least 5° or more in at least three adjacent vertebral bodies'. Anteroposterior (AP) and lateral views are required,² in a standing position with arms raised by 90°. The whole thoracolumbar spine and pelvis should be imaged. Changes may also include:¹

  • Narrow intervertebral disc spaces and lengthening of the vertebral bodies.

  • Irregular upper and lower vertebral endplates.

  • Schmorl's nodes - multiple herniations of the nucleus pulposus of the vertebral plates.

• MRI may occasionally be useful, mainly in pre-operative planning.

Management of Scheuermann's disease⁶

The first-line treatment is medical and includes rehabilitation and bracing. The earlier the start of treatment, the better the outcome, which highlights the importance of early diagnosis. Surgery is uncommon and must be limited to severe involvement after failure of conservative treatment.⁹

• For mild disease (hyperkyphosis of less than 60^o), stretching, lifestyle modification to avoid strenuous activity and weight-bearing and non-steroidal anti-inflammatories are recommended.²

• Physiotherapy may reduce pain, especially if the disease affects a short segment, but does not affect the progression of kyphosis.

• In more severe disease with a kyphosis of 60-80^o, a spinal brace may be used. Braces are typically advised for 12-24 months and are more effective in patients who are skeletally immature. It does not tend to improve the curve but can reduce progression.²

• Surgery is usually only used if there is a kyphosis of greater than 75^o leading to uncontrolled pain, unacceptable deformity or neurological deficit. It might be considered for kyphosis under 75^o with severe intractable pain.²³

• Cord decompression is carried out for neurological deficit and spinal fusion techniques are used for kyphosis correction and pain control.

• Over the period of a decade there has been an increase in spinal surgery for Scheuermann's disease, and a higher proportion of operations are in adults. Although there is a high risk of complications this is significantly less with new instrumentation techniques and an all-posterior approach.¹⁰

• The majority of patients who undergo surgery report a reduction in pain as well as an improvement in curve deformity.²

Complications of Scheuermann's disease

• Chronic back pain.

• Progressive and permanent deformity.

• Neurological deficit.

• Cardiorespiratory problems.

Prognosis

• Mild-to-moderate Scheuermann's disease rarely requires bracing or surgery.

• A Finnish study reporting on the 37-year follow-up of 49 people with Scheuermann's disease concluded that they have an increased risk of back pain and they are more likely to report difficulty carrying heavy loads and going upstairs without a rest. However, there was no correlation between the degree of their kyphosis and self-reported quality of life, quality of health or back pain.¹

• Neurological and cardiorespiratory complication risks are very low.