SCHEUERMANN's DISEASE

SCHEUERMANN DISEASE

Hitesh Gopalan U, MS, Senthilnathan MS MD.

Theories of Origin
 Scheuermann proposed that the kyphosis resulted from avascular necrosis of the ring apophysis of the vertebral body.
 Schmorl suggested that the vertebral wedging was caused by herniation of disc material into the vertebral body.
 Ferguson implicated the persistence of anterior vascular grooves in the vertebral bodies, which create a point of structural weakness in the vertebral body, which leads to wedging and kyphosis.
 Bradford et al suggested that osteoporosis may be responsible for the development of Scheuermann disease.
 Mechanical factors: Common in patients who do heavy lifting or manual labour.
 Ippolito and Ponseti suggested that a biochemical abnormality of the collagen and matrix of the vertebral endplate cartilage.

Criteria for Diagnosis (Sorenson criteria)
• More than 5 degrees of anterior wedging of at least three consecutive vertebrae at the apex of the kyphosis and vertebral endplate irregularities.
• Thoracic kyphosis of more than 45 degrees.


Natural history of the disease:

• Adult patients with mild deformity( Mean 71 degrees) present with chronic back pain.
• More severe defomities cause severe chronic back pain.
• Pulmonary compromise generally occurs if the curve is more than 100 degrees.
• Patients with type II Scheuermann's kyphosis almost never require surgery

Classification
– There are two forms of Scheuermann's kyphosis—type I and type II.
– The classic thoracic type (type I) has an apex between T7 and T9 and is associated with increased lumbar lordosis.
Type I (typical) again divided into 2 types
 Type a(thoracic) extends from T1-2 to T12-L1 and apex at T6-T8 and
 type b(thoracolumbar) extends from T4-5 to L2-3 and has apex at
Thoracolumbar junction.

– The thoracolumbar or lumbar type (type II) has a lower apex, which frequently is associated with reduced upper thoracic kyphosis or thoracic lordosis.
– Type II Scheuermann's kyphosis occurs more frequently in males in a slightly older age group (15 to 18 years).
– This form tends to be more painful but rarely leads to progressive deformity

Clinical Features:

* In Scheuermann’s disease the deformity does not disappear on lying supine or with hyperextension manouevre.
* Pain is usually at the apex of the deformity
* Kyphosis is often rigid and cannot be corrected by hyper extension
* Neurological examination is often normal, because kyphosis occurs gradually and over several segments
* The onset is often after lifting heavy weight from a flexed position.
* Lumbar Scheuermann is less common and the deformity is often minimal.
* Rarely, thoracic disc herniation, epidural cysts, or a severe kyphosis (>100 degrees) can cause neurologic deficit in patients (usually adults) with Scheuermann's kyphosis

Imaging:

• lateral x-rays: to measure vertebral wedging and measure Cobb’s angle of deformity
• May also reveal vertebral end plate irregularities, narrow disc spaces and Schmorl’s nodes
• In 20% to 30% of patients, the posteroanterior x-ray shows associated mild scoliosis in the area of the kyphosis.
• The scoliotic apex usually corresponds with the kyphotic apex.
• A lateral x-ray should be examined for spondylolisthesis in addition to kyphosis.
• In the later stages of Scheuermann's kyphosis, x-rays may show changes of degenerative arthritis, including decreased intervertebral disc spaces, marginal osteophytes, and ankylosis
• MRI: to rule out disc herniation if patient is planned for posterior surgery

Differential Diagnosis:
1. Postural kyphosis:
– In a forward bending test, the kyphotic deformity is accentuated, and the apex appears as a sharp angulation, in contrast to the smooth curve of a patient with postural kyphosis.
– A forward bending test also exposes any associated scoliosis.
– The hyperextension test helps the examiner understand the rigidity of the curve.
– A curve that is flexible or reduces significantly with hyperextension is typically postural and not Scheuermann's kyphosis, although in younger children a flexible round-back deformity may be the first sign of evolution to true Scheuermann's kyphosis.

Treatment:

Conservative:

• Bracing - effective in controlling the progression of deformity.
 Indicated in patients with kyphosis less than 1year of onset, curves between 50-70 degrees and apex below T7.
 Bracing is continued for at least 18 months.
 Acute application of a brace can influence the deformity and improve kyphosis by 40% to 50%; however, several articles have shown at least partial loss of this correction when brace wear is stopped.
 All kyphosis braces require careful orthotist attention to ensure fit and to recontour the posterior bars and pads every 2 months to gain further correction progressively.

• Pain usually responds to NSAID's and physical therapy.

• Surgical:
 Posterior correction with or without osteotomy and fusion.
 Anterior release has been recommended for deformities that do not correct to 50 degrees on stress views.
 Fusion level: Current recommendations are to include the proximal end vertebra (determined by the modified Cobb method) and to extend the fusion past the transitional zone to the first lordotic disc distally
 Traditional teaching is to restrict the correction to 40 degrees to prevent proximal or distal junctional kyphosis and implant pull out.
 Intraoperative neurologic monitoring is crucial during any surgery to correct kyphosis because the thoracic cord is at risk during correction and instrumentation. NMEPs and SSEPs are used for this.
 postoperative bracing for approximately 3 to 6 months

• Relative indications for surgery:
Kyphosis more than 70 deg, Deformity progression despite bracing, cosmesis, neurologic
deficits and failure of conservative treatment for pain.

Contraindications: Asymptomatic patient without cosmetic concerns.

Ref:
1. Papagelopoulos PJ, Klassen RA, Peterson HA, et al. Surgical treatment of Scheuermann's disease with segmental compression instrumentation. Clin Orthop 2001;386:139-149.
2. Otsuka NY, Hall JE, Mah JY. Posterior fusion for Scheuermann's kyphosis. Clin Orthop 1990;251:134-139.
3. Tribus CB. Scheuermann's kyphosis in adolescents and adults: diagnosis and management. J Am Acad Orthop Surg 1998;6:36-43.
4. Wenger DR, Frick SL. Scheuermann kyphosis. Spine 1999;24: 2630-2639.