SCHEUERMANN DISEASEHitesh 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.
