Postural Kyphosis

Key Points:

• Postural spinal balance is maintained by a complex interplay of the disc complex, ligaments, and muscles surrounding the vertebra 
• Normal thoracic kyphosis is considered to be 20˚-40˚ as measured from T2-T12 
• Postural kyphosis will present with a more gradual, rounded deformity than Scheuermann’s kyphosis
• The deformity is completely correctable on an exam or with improved posture
• Education of the patient and family is the most effective treatment 

Description:

• Posture is the relationship of the body to a vertical line passing through the body’s center of gravity
• Spinal stability and maintenance of an upright posture against gravity are maintained by a number of structures:
  • The disc complex: nucleus pulposus and annulus
  • Ligaments: anterior and posterior longitudinal ligaments, ligamentum flavum, interspinous ligament, apophyseal joint ligaments
  • Muscles: long spinal muscles, short intrinsic spinal muscles, abdominal muscles (Harrison, 1999)
• The spine will be in a relatively flexed position until the child begins walking upright
  • To counteract the head’s anterior position to the body’s vertical axis, cervical lordosis develops and centers the head over the pelvis
  • In order to match the flexed position of the hips and pelvis, the lumbar spine becomes lordotic 
  • Unchanged from its infantile position, the thoracic spine will remain kyphotic (Johnston, 2014)
• Normal thoracic kyphosis is considered to be 20˚-40˚ measured from T2-T12 (Fon, 1976)
  • The most common causes of hyperkyphosis in the adolescent are postural round-back deformity or Scheuermann’s kyphosis (Roussouly, 1999) 

Epidemiology:

• Postural kyphosis is a condition seen not infrequently in adolescents. Its specific incidence is not defined in the literature 
• The condition is most common in children who are taller than their peers and in young, adolescent girls with early breast development who are self-conscious about their bodies (Warner, 2014) 

Clinical Findings:

• Parental concerns over the deformity, more so than patient concern, are typically what brings the child to the attention of an orthopedist. 
• A gentle rounding of the spine in the thoracic region will be seen on a forward bend test.
  • The kyphosis in postural kyphosis is not as sharp or angular as that seen in congenital or Scheuermann’s kyphosis (Warner, 2014). 
• The deformity should be completely correctable on an exam or with changes in posture. 
  • The erector spinae muscles can contract to correct the thoracic kyphosis while contraction of the abdominal musculature will flatten the concomitant lumbar lordosis (Johnston, 2014).

Imaging Studies:

• Radiographs should show no osseous abnormalities in true postural kyphosis.
• Thoracic kyphosis can be assessed on a standard lateral radiograph with a Cobb angle measurement extending from the superior end plate of T2 to the inferior end plate of T12. 
  • The apex of normal thoracic kyphosis is the T6-7 disc space.
  • The thoracolumbar junction should be without kyphosis or lordosis. 

Treatment:

• No medical treatment is required for this condition owing to its benign natural history.
• A hyperextension brace is not indicated (Warner, 2014).
• Core strengthening exercises may provide some benefit and improve the adolescent’s posture, though compliance with any exercise program is difficult to achieve in an adolescent patient. 
• Education of both the parents and the patient may be the best treatment option (Johnston, 2014).
• Surgery is not indicated in this condition.

Complications:

• Postural kyphosis is a self-limiting condition that has no long-term sequelae. 

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