Overview

Scoliosis is a frontal plane deformity of the spine of >10 degrees, with frequent coexistence of rotational deformity. It is the most common pediatric spine defor­mity, and is classified into congenital, idiopathic (sub­types: infantile, juvenile, adolescent), neuromuscular and functional types (Table 14.6).

Embryology, Growth, and Maturation

Spinal development is a complex process, which begins in the first month of gestation when mesoderm cells surrounding the notocord begin to differentiate into sclerotomes. These will ultimately form vertebral bod­ies and arches. Injury in early gestation often affects other nearby organs, primarily the cardiac, renal, and gastrointestinal systems. Approximately 60% of those with spinal anomalies have other congenital malfor­mations, so abnormalities in these areas are essential to screen for (282).

14.6

Type of Scoliosis With Categorical Description

progress after maturity

Unlike limb growth, vertebral growth is nonlin­ear.

While race, heredity, physical activity, physical disability, and nutrition may affect growth, growth typically accelerates girls at Tanner stage 2 and in boys at Tanner stage 3 (283).

The use of Risser lines, seen by posterior ante­rior (PA) radiographs of the iliac crest, assist in stag­ing skeletal maturity and predicting future growth (Fig. 14.18). The Risser system is based on ossification of the iliac crest proceeding from the lateral to medial, and extends from grade 0 (no ossification) to grade 5 (complete fusion to iliac apophysis) (284,285). Risser 1 represents the period of most rapid skeletal growth, and correlation of the Risser's sign with the degree of a scoliotic curve can be predictive of curve progression (see Fig. 14.18).

Curve Classification and Naming

Scoliotic curves are named by their direction, location, and magnitude (Fig. 14.19). The curve's convex apex

Figure 14.18 Risser sign. Likelihood of progression is based on the Risser sign and curve magnitude. (From Ref. 375)

(most laterally deviated vertebrae from the sacral line) indicates its named direction and location, and mea­surement by the Cobb angle provides its most reliable magnitude (Fig. 14.20) (286). If more than one curve exists, the largest-degree curve is designated as major and the others minor. Curves over 60 degrees are asso­ciated with restrictive lung disease.

Rotation of the spine, commonly present with sco­liotic curves, is measured using a scoliometer when the child is bending forward, or radiographically by the Nash-Moe method or by CT scan (287,288).

History, Physical Exam, and Treatment Overview

The scoliosis exam will vary, depending on the patient's age and associated diagnosis, but important general information must be collected from all patients. A posi­tive family history is particularly pertinent in congenital and idiopathic scoliosis, and the presence of back pain may indicate a serious discitis or tumor. Rapid curve progression, bowel and bladder changes, recent trauma, associated weight loss, muscle weakness, or joint pain can point to other serious primary processes such as spi­nal cord syrinx or tethered cord, spinal fracture, rheu- matologic disease, osteoblastoma, or hip deformity.

Reflexes, strength, range of motion, general pos­ture, and gait must be examined. Seating systems and assistive devices should be assessed, as improper walker or crutch height and truncal weakness with poor seating support can affect spinal position in chil­dren with disabilities. Examination of the skin for cafe au lait spots, webbed neck or low hairline, and

Figure 14.19 Classification of scoliosis. Scoliosis is classified into general categories by level. (Adapted from Ref. 284).

Figure 14.20 The Cobb method of measuring curvature in scoliosis. The angle measured is formed by perpendicular lines drawn through the superior border of the upper vertebra and the inferior border of the lowest vertebra of a given curve.

hairy patches or skin dimples may lead to recognition of disorders such as Klippel-Feil, spina bifida occulta, or neurofibromatosis. Excessive height, arm span, or joint hyperextensibility may signal a connective tissue disorder of which scoliosis is only a presenting symp­tom. Leg length, straight-leg raise, and range of motion should be checked, as length discrepancies, asymme­try, contracture, or pain may point to hip dysplasia or an underlying neurologic disorder such as hemiplegia or herniated disk.

Examine the back for pelvic obliquity, elevation of either iliac crest, or asymmetry of the scapula or shoulder girdle. Forward bending (Adam's test) with the feet and palms together may show asymmetrical prominence of the rib cage (vertebra rotate into the convexity of the curve), which can be measured with a scoliometer. A rotation of over 7 degrees warrants fur­ther investigation. Side bending may help assess the flexibility or rigidity of a curve, which is important when considering treatment options.

Curve Documentation. A full spine PA radiograph is usually appropriate for screening purposes, although certain curves (ie, congenital, infantile) may require CT or MRI evaluation. Curves with significant rota­tional components or kyphosis may require lateral views. Radiographs should be taken standing, if pos­sible and, if wearing an orthosis, both in and out of the brace. Cobb angles, which have proven reliable in tracking curves, should be followed every three months to a year, depending on the rate of progres­sion (286). Serial evaluations should continue until growth is complete, although neuromuscular curves often progress after maturity, so continued screening is warranted (284).

General Treatment Options. Orthotic management is not appropriate, effective, or recommended for all forms of scoliosis. Long-term bracing, while reducing curve progression and maintaining flexibility, needs to be considered carefully with respect to function, social development, and self-esteem (285).

Curves less than 40 degrees are typically com­patible with bracing, but their location affects brace choice. Curves with apex at or below T7 are typically managed with a soft or rigid TLSO, which allows more functional activity than the Milwaukee brace used for curves above T7 (Fig. 14.21). This brace often incorporates a chin and head pad, is more restrictive, and is less well tolerated. It is recom­mended that both braces be worn 16-24 hours a day to be effective (282). Removing the brace for an hour or two per day to accommodate athletic or recrea­tional pursuits is not uncommon.

Surgical Interventions. Achieving a balanced spine (head and shoulders over sacrum), a solid arthrode­sis, and a reduction in the deformity are the primary goals of surgical intervention. Surgical techniques vary by type of scoliosis. Titanium instrumentation is recommended when it is clear that MRI imaging will be needed in the future, given the frequency of coex­isting organ and developmental abnormalities seen in some children. Continuous intraoperative spinal monitoring (somatosensory-evoked potentials, motor- evoked potentials) is important for preventing neu­rologic injury during surgery (288). Complications of surgery vary with patient diagnosis, curve size, and a multitude of other factors, but infection, pseudarthro­sis, anemia, hypotension, and hardware failure are the most common.

Figure 14.21 Types of braces. These are common braces and generalizations about their use. (Adapted from Ref. 284.)