India-OrthIntroduction
Scheuermann disease is the most common cause of structural kyphosis
in adolescents and can be a source of painful kyphosis in adults.
Definition:
Scheuermann kyphosis is a structural hyperkyphosis defined
radiographically as anterior wedging of ≥5° of at least three
consecutive vertebral bodies.
Incidence
-The disease occurs in 0.4% to 8.3% of the population.
-incidence in men may be higher than that in women.2-5
-Although the age at onset is approximately 10 to 12 years, a subset of
patients present in adulthood
classification:
| Typical | Atypicaltype II or lumbar Scheuermann | |
| incidence | More common | Less |
| site | thoracic | Thoraco-lumbar ,lumbar |
Atypical kyphosis is often seen in active, athletic periadolescent .These patients typically report
pain that resolves with rest and activity modification.
Pathogenesis
To date, no conclusive evidence has elucidated the etiology of Scheuermann
kyphosis, but numerous hypotheses have been proposed.
-Scheuermann1 hypothesis-originally postulated that the deformity was secondary to osteonecrosis of the ring apophysis of the vertebral bodies, resulting in cessation of anterior growth and an eventual kyphotic deformity.
- Schmorl hypothesized -that disk material herniated into the vertebral
bodies was responsible for the kyphosis because of the resulting decrease
in anterior disk height, increase in anterior pressure, and subsequent growth disturbance
-Bradford et al suggested that relative osteoporosis may be responsible,
based on the premise that vertebrae with below-normal density
would be prone to collapse from compression.
-Ogden et al suggested that abnormal biomechanical stresses lead to an altered remodeling response in the vertebral bodies, resulting
in kyphosis
-Finally, genetics has been suggested as a possible associative factor.
Clinical Presentation
1) Pain secondary to the deformity.
2) Physical examination demonstrates thoracic hyper kyphosis, which exhibits varying degrees of flexibility. Typically, hyper kyphosis is accompanied by lumbar hyper lordosis and increased cervical lordosis.
4) In adults with Scheuermann disease, pain in the lumbosacral area is
highly suspicious for associated spondylolysis.
5) Neurologic abnormalities are exceedingly rare. Neurologic symptoms may be secondary to severe congenital kyphosis, dural cysts, or disk herniation.
6) Complaints related to pulmonary function are also rare. Restrictive pulmonary disease was present only with kyphotic curves >100°.
7) Other causes of fixed thoracic kyphosis should be ruled out, including
healed compression fractures, kyphosis resulting from a previous
laminectomy, ankylosing spondylitis, neoplastic processes, and infection.
| Postural(roundback deformity | sheurmann | |
| create a round back deformity that often disappears with forward bending | Forward bending typically accentuates the thoracic deformity, with a sharp transition noted in the thoracolumbar region | |
| lacks the morphologicchanges wedging of the vertebral bodies,
Schmorl nodes, and end plate irregularities |
||
| less angulated and is typicallysomewhat more flexible correcting well
when the patient is in the supine position.
|
||
Radiographic Evaluation
1)Routine standing AP and lateral radiographs of the entire spine should be obtained to evaluate patients with Scheuermann kyphosis
-Lateral radiograph –to assess sagittal balance
-AP radiograph –to assess scoliosis
-Hyperextension lateral radiograph of
the thoracic spine to assess the flexibility
of the deformity.
- two curve patterns can
be identified on radiographs.
| Curve pattern | Typical | atypical |
| apex | between T6 and T8 | near the thoracolumbar |
| extend | from T1 or T2 toT12 or L1. | from T4-5 to L2-3 |
| More progressive and more symptomatic |
Management
Indications for management of adult Scheuermann kyphosis
1) Progression of the deformity,
2) Pain,
3) Cosmesis
4) cardiopulmonary
5) neurologic compromise.
Nonsurgical
Nonsurgical management of adult kyphosis consists of
1) Anti-inflammatory medication
2) Physical therapy, including postural improvement exercises and trunk extensor strengthening. These exercises will not necessarily lessen the kyphosis but may improve general physical conditioning and alleviate pain.
Surgical
Goal
1) Correction of kyphosis and
2) Prevention of deformity progression
3) Relief of associated pain.
Indications
1)curves >60°
2) pain that is not relieved with nonsurgical measures.
3) unacceptable cosmesis.
4)neurologic deficits
5)Cardiopulmonary indications for surgical intervention are rare and appear
only in patients with curves >100°.
Approach
Surgical management of Scheuermann
kyphosis can be performed via
1)posterior-only,
2) anterior-only, or
3) combined anterior-posterior approaches.
The anterior-only approach involves anterior interbody release and
fusion with segmental instrumentation.
Advantages include release of the ALL and creation of a large intervertebral
fusion mass under compression rather than tension, as occurs in posterior surgery.
Posterior-only approaches have the advantages of decreased blood loss
and shorter surgical times, thereby avoiding the need for thoracotomy.
These approaches do not interfere with the anterior blood supply to the
spinal cord. However, posterior-only approaches may be unsuitable for
patients with rigid curves that do not correct to <50° on hyperextension
radiographs. Good results with posterior-only approaches have been
reported so long as no anterior bony bridging has occurred at the time of
surgery. Because the anterior longitudinal ligament (ALL) is still intact, instrumentation introduced through the posterior-only approach
is under continual tensile stress; without a well-done fusion, the risk of higher rates of implant failure and pseudarthrosis exists.
A combined anterior-posterior approach
may be required for surgical management of severe kyphosis. This
approach typically involves an anterior release with posterior spinal instrumentation and fusion. It is reserved for adults with large curves
(>80º) and the most rigid deformities, which do not correct on hyperextension
bending and curves with evidence of rigid anterior bony bridging. Advances in posterior instrumentation have made the posterior-only approach the preferred approach because it results in better correction, less blood loss, and shorter surgical times.
Complications
Surgical complications are seen more frequently in adults than adolescents.
The most frequently encountered surgical complications are loss of
correction, junctional kyphosis, and wound infection.
