Matthew J. Bueche
Spinal deformity is a major concern in the adolescent population. Teens with poor posture are frequently brought to the physician by concerned parents, whereas those with more serious structural scoliosis and kyphosis may escape attention. Marked deformity can exist without symptoms. Although the efficacy of school screening programs is controversial, clinicians should routinely examine adolescents for spinal deformity, as treatment may improve the outcome.
Scoliosis is a lateral curvature of the spine, usually associated with rotational deformity of the spine and trunk. Scoliosis is defined as a curvature of 10 degrees or greater on a frontal radiograph (measured by the Cobb Method [Fig. 15.1]).
FIGURE 15.1 The Cobb method of radiographic measurement of scoliosis. A line is drawn parallel to the inferior end plate of the lower end vertebra (LEV) (the vertebra that is most tilted) (1), another line is drawn at the superior border of the upper end vertebra (UEV) (3), perpendicular lines are drawn from each of these previous lines (2 and 4), and the intersecting angle is then measured. Drawing the perpendiculars keeps the measurement from running off the edge of the film. A similar method is used on the lateral film to measure sagittal plane curves. (Adapted from O'Brien MF, Kuklo TR, Blanke KM, et al., eds. Radiographic measurement manual. Spinal Deformity Study Group. Memphis, Tennessee: Medtronic Sofamor Danek, 2004:110.)
Scoliosis is a condition rather than a diagnosis. Most adolescents have adolescent idiopathic scoliosis (AIS), a condition with no apparent cause. Scoliosis may be associated with neuromuscular diseases such as spastic quadriplegic cerebral palsy and Duchenne muscular dystrophy. Congenital scoliosis is deformity secondary to vertebral malformations. Nonstructural or functional scoliosis may result from leg length discrepancy or from splinting due to back pain. Scoliosis may be part of a syndrome or disease such as Marfan syndrome, neurofibromatosis, or myelodysplasia.
There is no known cause of idiopathic scoliosis. It is usually categorized into three age-groups:
of curve progression increases with curve severity and treatment may be initiated at similar curve magnitudes.
Approximately 2% to 3% of adolescents have a curve >10 degrees and 0.5% have a curve >20 degrees. Although minimal curves occur as often in boys as in girls, curves requiring treatment are found seven times more frequently in girls (Rogala et al., 1978).
The etiology of AIS is believed to be multifactorial (Miller, 1999):
Long-term complications of continued curve progression including cosmetic effects, back pain, neurological compromise, and restrictive pulmonary disease leading to cor pulmonale and death have been described. Fifty-year follow-up of untreated AIS found a tendency toward continued progression of the deformity (Weinstein et al., 2003). Back pain was present more frequently in patients than in the age-matched control group, although most patients reported only mild or moderate pain. Shortness of breath was reported more frequently in the AIS group. In the same study, 3 of the 36 deaths were likely related to the scoliosis.
Adults treated for AIS were found to recall transient body-image dissatisfaction and negative peer interactions during adolescence. Lower body-image scores persisted for several years in surgical patients (Noonan et al., 1997).
Risk Factors for Progression
A combination of the following factors can be helpful in predicting as many as 80% of progressive curves (Peterson and Nachemson, 1995).
The American Academy of Orthopedic Surgeons recommends screening girls at ages 10 and 12 (grades 5 and 7) and screening boys once at age 13 or 14 years (grades 8 or 9) (AAOS, 1992). The Scoliosis Research Society concurs with this recommendation. In addition, some state laws mandate school screening for scoliosis. In contrast, the U.S. Preventive Services Task Force's (USPSTF's) Guidelines for the Guide to Clinical Preventive Services states that “The
USPSTF found fair evidence that treatment of adolescents with idiopathic scoliosis detected through screening leads to moderate harms, including unnecessary brace wear and unnecessary referral for specialty care. As a result, the USPSTF concluded that the harms of screening adolescents for idiopathic scoliosis exceed the potential benefits” (U.S. Preventive Services Task Force, 2004).
FIGURE 15.2 The Risser sign. The iliac apophysis appears first at the anterior superior iliac spine; ossification then progresses medially toward the posterior superior iliac spine. The crest is divided into four equal quadrants with stages 1 through 4 coinciding with extension of the ossification center into each quadrant and stage 5 being complete fusion of the physis (Risser, 1958). (From O'Brien MF, Kuklo TR, Blanke KM, et al., eds. Radiographic measurement manual. Spinal Deformity Study Group. Memphis, Tennessee: Medtronic Sofamor Danek, 2004:110.)
The sensitivity, specificity, and positive and negative predictive value of screening tests depend on the degree of curvature defined as abnormal, the training of the screener, and the prevalence in the population. Properly trained clinicians using an inclinometer (Fig. 15.3) can evaluate the need for scoliosis radiographs. “Schooliosis” or the over-referral of normal adolescents from school screening programs is a known phenomenon. Better communication and proper technique should allow screening to continue at efficient levels (Dvonch et al., 1990).
The patient history should include the following:
Evaluation of suspected scoliosis should be directed at the deformity, its cause, and complications. The general examination should include the following:
Performed with the patient standing, wearing underwear and a gown open in the back
Physical examination signs indicative of nonidiopathic scoliosis are listed in Table 15.2.
Recommendations for Radiographs for Suspected Scoliosis
Radiographic studies are recommended for adolescents with an ATR >7 degrees, measured by an inclinometer. This threshold value balances the risks of false-positive and false-negative results (Bunnell, 1993).
Which Radiographs to Order?
The standard films for the evaluation of scoliosis are standing posteroanterior and lateral spinal radiographs using 36-in. films taken at 6-ft distance to allow measurement of the curve using the Cobb method and Risser staging of the iliac apophysis. Directing the beam from posterior to anterior measurably decreases the radiation dose to the breasts and thyroid (Levy et al., 1996).
Skeletally immature patients at risk for curve progression can be followed up with posteroanterior radiographs every 6 to 12 months.
FIGURE 15.3 The inclinometer (scoliometer). The device is centered over the spinous process at the area of greatest asymmetry. The patient flexes at the waist sufficiently to bring the right thoracic area (A) and left lumbar area (B) parallel to the floor. (From Weinstein SL, ed. The pediatric spine. Principles and practice, 2nd ed. Philadelphia: Lippincott Williams & Wilkins, 2001 Figure 4, page 135.)
Radiographic indications of nonidiopathic scoliosis are listed in Table 15.3.
Magnetic Resonance Imaging
Magnetic resonance imaging (MRI) of the full spine is recommended for adolescents with the following findings:
Criteria for Referral
Consultation with an orthopedic surgeon (ideally, one who specializes in pediatric orthopedics or orthopedic spinal surgery) should be considered for
Major treatment options include observation, bracing, and surgery (Table 15.4). Treatment choices in AIS often involve consideration of the teen's physiological (not chronological) maturity, curve magnitude and location, and the potential for progression.
Brace therapy should be considered in the skeletally immature adolescent who has 30 to 40 degrees of curvature or who has a curve >25 degrees with a demonstrated increase of 5 degrees. The primary goal of brace management is to halt curve progression. This treatment modality should not be expected to permanently improve curvature. Although curve magnitude typically decreases during brace treatment, this improvement is often lost in the years following brace weaning.
There are a number of different bracing systems (e.g., Boston, Milwaukee) that have been used to prevent the need for surgery. The Milwaukee brace features a neck ring that may cause cosmetic concerns. Most other scoliosis braces are variants of the thoraco–lumbar–sacral orthosis (TLSO), an underarm brace. It is generally recommended that the braces be worn almost full-time, with removal for bathing and sports participation. Part-time (18 hour/day) programs may be more acceptable to the patient who refuses to wear the brace to school (Green, 1986).
Despite a high incidence of noncompliance, outcomes are better than would be expected from the natural history alone (Nachemson and Peterson, 1995). Less than full-time wear may decrease the psychosocial impact of brace treatment. However, a meta-analysis of brace studies indicated a trend toward decreasing efficacy with decreased time in brace (Rowe et al., 1997). Another study showed that decreasing the prescribed hours of daytime brace wear did not increase compliance (Takemitsu et al., 2004). Nighttime-only braces (e.g., Charleston, Providence) avoid some of the compliance problems associated with daytime braces. Such braces attempt to make up for decreased treatment time by hyper-correcting the curve into the opposite direction (difficult to accomplish in a brace designed for an upright patient, but more feasible when recumbent). These braces have shown promise in patients with specific curve patterns. Among those treated with the Charleston brace, 66% had <5 degrees progression and only 16% required subsequent surgery at long-term follow-up (Price et al., 1997).
Skeletal maturation, defined as no further changes in height and a Risser stage IV, is usually considered the endpoint for brace use.
Surgical management is recommended for skeletally immature patients who have a curve >40 to 45 degrees or in skeletally mature patients who have curves >50 degrees, particularly if curve progression has been documented. Surgery fuses the vertebrae in the curve, preventing further progression. Rods are implanted as internal fixation, both stabilizing the spine to allow for reliable fusion and allowing for considerable curve correction. Post-operative bracing is frequently unnecessary. Hospital stays are usually for less than a week and students miss approximately 1 month of school. Although mid- or low-lumbar fusions may cause long-term back stiffness, this does not commonly occur with thoracic fusions.
Exercise programs have not been shown to alter the natural history of idiopathic scoliosis. Electrical stimulation has proved to be ineffective for scoliosis in multiple studies.
Normal sagittal plane posture includes rounded shoulders (thoracic kyphosis) and sway-back (lumbar lordosis). Increased kyphosis in adolescents is commonly caused by juvenile postural roundback and less commonly, by Scheuermann kyphosis.
Adolescent Roundback (Juvenile Postural Roundback)
Many adolescents manifest an excessively kyphotic posture. The spine is flexible enough that the adolescent can stand straighter if they desire, although they may complain of muscle pain and fatigue. On forward bending, the spine shows a smooth curvature when viewed from the side. Lateral radiographs may show the increased thoracic kyphosis, but the individual vertebrae and disc spaces will appear normal. It is more common among girls than among boys. It is usually painless.
An exercise program directed by a physical therapist may be helpful if the adolescent is in pain or unhappy with his or her appearance.
Scheuermann kyphosis is a relatively rigid, abnormally increased kyphosis of the thoracic and thoracolumbar spine that does not correct with hyperextension of the spine. The kyphosis results from anterior vertebral wedging in the affected area of the spine. The matrix of the vertebral end plate has characteristic changes in the ratio of collagen to proteoglycans that leads to an altered ossification process. The exact etiology of Scheuermann disease is unknown but is thought to include excessive
stress, genetic predisposition, and congenital malformation of the vertebral end plates. The prevalence is estimated to range from 0.4% to 8.0% in the adolescent population, with a peak age of onset at 12 to 13. There is equal incidence in boys and girls.
Definition and Classification
The radiographic diagnosis of Scheuermann kyphosis is made on a standing lateral 36-in. film. The criteria include the following:
The classification of Scheuermann kyphosis is made by the location of the kyphosis. Thoracic curves are by far the most common (75%) and thoracolumbar curves are more likely to progress even after skeletal maturity. “Lumbar Scheuermann disease” is distinct from true Scheuermann kyphosis in that it does not have the anterior wedging of the vertebral bodies.
These deformities are not completely corrected with forward bending or prone hyperextension maneuvers.
In addition to adolescent roundback, there are a number of other processes that must be considered before diagnosing Scheuermann kyphosis.
Most patients with <75 degrees of kyphosis have a benign progression of their disease with some deformity, back pain, and fatigue. When patients with Scheuermann kyphosis were compared with healthy age- and sex-matched controls, they were found to have more intense back pain, jobs that tended to have lower requirements for activity, less range of motion of extension of the trunk and less strong extension of the trunk, and different localization of the pain. No significant differences were noted between self-esteem, social limitations, and level of recreational activities or preoccupation with physical appearance (Murray et al., 1993).
Treatment is controversial and not all patients require intervention. The three main treatment modalities for patients with Scheuermann kyphosis are exercise, bracing, and surgery.
For Teenagers and Parents
http://www.scoliosis-assoc.org/. Scoliosis Association, Inc., an international information and support organization.
http://www.scoliosis.org/. National Scoliosis Foundation. Patient advocacy and information.
http://orthoinfo.aaos.org/fact/thr_report.cfm?Thread_ID=262&topcategory=Children and http://orthoinfo.aaos.org/brochure/thr_report.cfm?Thread_ID=14&topcategory=Spine. American Association of Orthopedic Surgeons brochure on Childhood Scoliosis.
http://www.niams.nih.gov/hi/topics/scoliosis/scochild.htm. National Institute of Arthritis and Musculoskeletal and Skin Diseases frequently asked questions about scoliosis.
http://www.mayoclinic.com/health/scoliosis/DS00194. Mayo Clinic information on Scoliosis.
For Health Professionals and Patients
http://www.srs.org. The Scoliosis Research Society.
http://www.nlm.nih.gov/medlineplus/scoliosis.html. Medline plus health information.
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