Adolescent and pre-adolescent kyphosis will usually manifest into two groups: postural kyphosis and Scheuermann's kyphosis.1-7
Postural kyphosis manifests as an increase in thoracic kyphosis while standing. Curve flexibility is seen when the patient stands erect as opposed to when the posture is relaxed. When the patient is prone or supine, the "deformity" resolves spontaneously. This nonprogressive condition is commonly seen in middle-school-aged children, especially girls, and almost always resolves by itself and requires no specific treatment; however, thoracic hyperextension exercises may be helpful.6
Scheuermann's disease, or juvenile discogenic disease, was first described in 1921 by Holger Scheuermann,5 who described it as a typically juvenile kyphotic disorder that could be distinguished from postural kyphosis on the basis of peculiar rigidity. Although many theories have been proposed, the cause of Scheuermann's disease is unknown. Currently under investigation are the roles of juvenile osteoporosis, hereditary factors, biomechanical factors, and a variety of other causes.6,8-14 The disease is identified radiographically by the appearance of vertebral wedging in the thoracic or thoracolumbar spine, and it disturbs the growth of the vertebral endplates (Figure 1) .1,3,5,8,10,13-18
Scheuermann's disease is a condition of unknown cause that produces an increased thoracic kyphosis (>40°) with true structural changes within the thoracic vertebra with 5° of wedging in each of three adjacent vertebrae measured on side-view radiographs.1,6-9,14,16,18-21 The apices are commonly between T7 and T9.1,3,8,9,14,16,18 The localized deformity is usually painless. There is probably a strong hereditary pattern.10 A subtype of Scheuermann's disease occurs in the lumbar spine with apices between T10 and T12.3,16,19 This is most common in late-adolescent boys who are involved in heavy lifting tasks.
The changes of the vertebra and disc are considered to reflect the physical stress effects.14The incidence of Scheuermann's disease varies according to the literature. Sorensen7 reported a 0.4 percent to 8 percent incidence in the population. Bradford9 noted an incidence as great as 10 percent. The incidences in males and females also vary according to the literature. Murray et al.21reported a male-to-female predominance of 2.2 to 1, whereas Winter22 reported that the ratio was nearly equal.
Clinically, these patients range in age from 10 to 15 years.3,9,15 Back pain and cosmesis are predominant clinical complaints. Upon forward bending, the patient with Scheuermann's disease will present with an area of sharp angulation near the apex of the kyphosis, usually near T7. When standing, the patients appear "slouched" with a rounded shoulder appearance. Ascani et al.8 noted that patients with Scheuermann's disease often have a more athletic body stature and present with contracture of the pectoral muscles and hamstrings.
Bradford9 suggested the following criteria be used in radiographically identifying Scheuermann's kyphosis in the adolescent patient:
Irregular upper and lower vertebral endplates.
The apparent loss of disc space height.
Wedging of more than 10° in one or more vertebrae.
The presence of a hyperkyphosis greater than 40° (Figure 2) .
The only two documented methods of nonoperative treatment for Scheuermann's are corrective casts and the Milwaukee brace.2,22-27 Orthotic management has been shown to be effective in controlling a progressive curve in the adolescent patient. Adolescent patients typically present for medical attention because of pain or cosmetic deformity. Early treatment may be limited to observation and exercises, whereas patients who have kyphosis as great as 80° and growth remaining may benefit from bracing.6,14
Treatment is dependent upon the magnitude of the deformity, pain complaints, and patient maturity. Observation is done for deformity of less than 60° and brace treatment for curves between 60° and 80° if the patient is skeletally immature. Surgery is occasionally required.22,28-32
Sachs et al.27 reviewed 132 patients and found an initial mean correction of 50 percent using the Milwaukee Brace. The mean full-time wearing period was 14 months, and the part-time period was 18 months. Apical wedging improved from a mean of 8.4° before treatment to 8.1° after treatment. For the more common thoracic form with apices superior to T8, the Milwaukee brace's effectiveness has been documented,6,18,24-28 and the brace is usually the treatment of choice (Figure 3 and Figure 4) .
Other types of orthoses have been used to treat thoracic Scheuermann's disease, but there is a scarcity of literature to support their effectiveness. In addition, it is commonplace to treat thoracolumbar Scheuermann's disease with a thoracolumbar spinal orthosis (TLSO), and many clinicians have experienced "good" results using this type of Scheuermann's kyphosis, but there is little literature to support the effectiveness of this approach.
There are differences in starting orthotic management for idiopathic scoliosis and Scheuermann's disease.25 A successful result in idiopathic scoliosis requires an actively growing child, whereas Scheuermann's disease requires only active vertebral apophyses.23,25 Therefore, orthotic treatment for Scheuermann's disease is still effective after vertical growth cessation, as long as the vertebral apophyses are still immature.In the current absence of a reliable correlation between hours of orthosis wear per day and outcome of orthotic treatment, 23 hours of wear per day is still the standard prescribed management of Scheuermann's disease.
The decision to wean a patient from an orthosis for Scheuermann's kyphosis is significantly different from that of weaning a patient from an orthosis for idiopathic scoliosis. Scheuermann's disease may be divided into two categories: 1) patients who present with multiple uniform wedges of >5° over three or more vertebrae without the apical wedge being significantly greater than the adjacent wedges; and 2) patients with significant apical wedging.2,25
For patients with multiple uniform wedges, curve correction is usually rapid, taking 9 to 18 months, and wedge healing is also rapid. Once correction is obtained, gradual weaning may ensue, with progressive cessation of the orthosis in 2- to 4-hour intervals. With correction maintenance, the total weaning phase may be accomplished in approximately 9 months.25
For patients with excessive apical wedging, a longer period of wearing is required. Bradford et al.23 reported that weaning should commence when significant apical wedge remodeling has occurred. In their study, patients had an average pre-orthosis apical wedging of 8.5°, and after orthotic management of approximately 34 months, had an apical wedging of 2°. For this category, remodeling of the apical wedge of 5° is considered the benchmark to begin weaning. Weaning should then proceed as previously described.
Whereas the literature supports the usage of the cervicothoracic-lumbosacral orthosis for the treatment of Scheuermann's kyphosis,6,18,24-28 these studies are retrospective and difficult to compare because indications for usage, weaning procedures, and overall orthotic protocols vary. In addition, there is a case to be made that, in the absence of pain and progression, treatment may not be necessary for these patients because the condition of vertebral osteochondrosis (Scheuermann's disease) is relatively benign when compared to the possible sequelae of untreated idiopathic scoliosis.21
Evidence of the necessity to treat patients with Scheuermann's kyphosis is weak in terms of weighing the cost risk-to-benefit factors. Is requiring a patient to wear an orthosis during their pre-adolescent and adolescent years worth the outcome of improved cosmesis? Will orthosis wearing truly treat the pain? If so, will the outcome be worth the orthosis wearing? Prospective clinical studies of the cervicothoracic-lumbosacral orthosis and TLSO treatment of Scheuermann's kyphosis are still needed.
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