In Depth Review of Scoliosis

This work provides information about the causes, diagnosis and scientifically documented, effective available treatment options for common types of spinal deformity.

In Depth Review of Scoliosis: Introduction

Figure 1a&b Figure 2a&b

When one views a normal spine form behind, the back appears straight and the trunk symmetrical. When the normal spine is viewed from the side, curves are seen in the neck, upper trunk and lower trunk. The upper trunk has a gentle rounded contour called kyphosis and the lower trunk has a reverse direction of the rounded contour called lordosis. Certain amounts of cervical (neck) lordosis, thoracic (upper back) kyphosis and lumbar (lower back) lordosis are normally present and are needed to maintain appropriate trunk balance over the pelvis (Fig. 1a&b). Deviations from this normal alignment may reflect abnormal kyphosis or lordosis or, more commonly, scoliosis. Scoliosis Scoliosis is defined as a side-to-side deviation from the normal frontal axis of the body (Fig. 2a&b).Although traditional, this definition is limited since the deformity occurs in varying degrees in all three planes: back-front; side-to-side; top-to-bottom. Scoliosis is a descriptive term and not a diagnosis. As such, a search is made for the cause. In more than 80% of the cases, a specific cause is not found and such cases are termed idiopathic, i.e., of undetermined cause. This is particularly so among the type of scoliosis seen in adolescent girls. Conditions known to cause spinal deformity are congenital spinal column abnormalities, neurological disorders, genetic conditions and a multitude of other causes. Scoliosis does not come from carrying heavy things, athletic involvement, sleeping/standing postures, or minor lower limb length inequality.

Figure 3a Adam's Bend Test - clinical (Frontal view) Figure 4 Scoliosis - clinical (Posterior view)

Clinical Clinical evaluation focuses on history and physical examination findings. Consideration is given to circumstances surrounding the patient's birth, delivery and development histories. Was the pregnancy full term? What was the child's birth weight? When did the child begin to walk?--are some of the important guide posts which are sought. Abnormalities in these areas may lead one to consider neuromuscular or congenital etiologies. With congenital anomalies, if one congenital anomaly is found, others are sought, e.g., kidney abnormalities are often associated with congenital scoliosis. Intermittent backache may occur with idiopathic scoliosis, but complaints of pain radiating into the legs, night pain, or systemic complaints (for example changes in bowel or bladder habits) are highly abnormal and are not common complaints in patients with idiopathic scoliosis and usually require further study. A family history of spinal deformity is looked for since certain types of spinal deformity are more prevalent within families. Physical examination centers on assessment of trunk symmetry. The Adam's forward bend test is done with the patient bending forward with arms extended and knees straight. Asymmetry of the trunk when viewed from the front or the back as well as abnormal increases or decreases in lordosis or kyphosis when viewed from the side are assessed (Fig.3). This test is used during school screening for scoliosis. The test is sensitive to detect trunk asymmetry but it is not specific for spinal deformity. A common finding that is often misinterpreted as spinal deformity is truncal asymmetry from unequal trunk muscle development on the patient's dominant hand side. Further physical findings depend on the patient's deformity location and magnitude. Shoulder heights may be uneven and there may be an increased space between the elbow and trunk because of trunk deviation (Fig.4). Prominence of a "hip", pelvis or breast may be seen. Examination of the skin overlying the spine assesses the presence of dimples, sinuses, hairy patches and skin pigmentation changes. The effect of any limb length inequality is tested with the patient standing on blocks to level the pelvis or seated on a flat surface. Neurological examination includes evaluation of the function of the muscles and nerves of the upper and lower limbs.

In Depth Review of Scoliosis: Radiographic Imaging

Figure 5 Screening PA erect Figure 6 Risser's sign and triradiate cartilage status

Initial imaging evaluation of a patient suspected of having scoliosis is by a standing posterior-anterior thoracolumbar spine radiograph done on a single long film. Modern radiographic techniques minimize radiation exposure (Fig.5). A standing side view radiograph of the thoracolumbar spine is suggested if significant deformity is present in the front-to-back (sagittal) plane. Radiographs are assessed for spinal column contour and to rule out congenital, developmental, degenerative or neoplastic abnormalities. The amount of each deformity is calculated using a standard, reproducible measurement technique. An estimate of skeletal maturity is made by assessment of the growth areas at the upper pelvis and hips (Fig.6). Specialized imaging studies such as (CT scans or magnetic resonance imaging (MRI)) may occasionally be needed. Magnetic resonance imaging is done to evaluate the spinal cord and spinal nerves (Fig.7). As with all studies, MRI is done for a specific indication and correlated with clinical examination. Myelography, a radiographic study which uses an injected dye to provide contrast to study the spinal canal and its contents, has been largely replaced by magnetic resonance imaging techniques. CT scans are used to provide improved definition of abnormalities of vertebral size, shape or number (Fig.8). Figure 7 Lateral T-L spine Figure 8 Congenital lumbar scoliosis - 3D

In Depth Review of Scoliosis: Congenital and Neuromuscular Scoliosis

Figure 9a Congenital Scoliosis (AP radiograph) Figure 9b Congenital Scoliosis (lateral radiograph) Figure 9c Congenital Scoliosis (CT scan of hemivertebra) Figure 10ab Spinal deformity in Muscular dystrophy (Pre-op) Figure 10cd Spinal deformity in Muscular dystrophy (Post-op)

Congenital Scoliosis Congenital scoliosis is caused by abnormal vertebral formation. Vertebral absence, partial formation or lack of separation can cause asymmetrical growth and resultant deformity (Fig.9). Patients with congenital scoliosis require a renal ultrasound to rule out renal anomalies such as a single kidney which is the most common associated finding. Magnetic resonance imaging may be necessary to rule out suspected associated abnormalities of the spinal cord or spinal nerves if clinical neurologic examination findings are present. The treatment of congenital scoliosis is individualized and dependent upon the type of vertebral malformation. Early surgical intervention may be required to prevent deformity progression. Neuromuscular Scoliosis Spinal deformity is common and often severe in patients with neuromuscular disease especially in those patients who do not walk because of their underlying neurological disease. Seating modification and bracing in the vast majority of cases have no long-term effect on the natural, i.e., untreated course, of spinal deformity in neuromuscular disease. Such techniques may improve sitting ability but do not alter curve progression. Surgical correction and stabilization are done to prevent curve progression. With modern spinal instrumentation and surgical techniques, most patients do not require post-operative immobilization with braces or casts. In patients with muscular dystrophy, the curve often increases when walking ability diminishes. Surgical intervention is indicated for progressive spine deformity in patients with muscular dystrophy while pulmonary function is still adequate, i.e., preferably when the curves are less than 300 (Fig.10). Myelodysplasia (spina bifida) often produces major progressive deformities from both paralytic and congenital factors, particularly in patients with high levels of paralysis. Progressive spinal deformity in patients with cerebral palsy often leads to difficulty with seating and care, especially in patients who do not walk (Fig. 11). Figure 11a Spinal deformity in cerebral palsy (Pre-op) Figure 11b Spinal deformity in cerebral palsy (Pre-op) Figure 11c Spinal deformity in cerebral palsy (Post-op)

In Depth Review of Scoliosis: Idiopathic Scoliosis

Figure 12 Adolescent idiopathic scoliosis with significant progression over two years Figure 13a Infantile Idiopathic Scoliosis of 20 month-old boy (clinical photo) Figure 13b Infantile Idiopathic Scoliosis of 20 month-old boy (radiograph) Figure 14 7yr old boy with juvenile idiopathic scoliosis

Idiopathic Scoliosis - Infantile; Juvenile; Adolescent Idiopathic scoliosis is considered in three age groups: Infantile--from birth to three years of age, juvenile--from greater than three years of age through nine years of age and, adolescent from 10-18 years of age. The adolescent type is the most common and represents about 80% of this type of scoliosis. In addition to the amount of spinal deformity, the patient's physiological age is assessed, i.e., is growth completed or is there more potential spinal growth (Fig.12). In the latter case, potential curve progression is related to the time remaining until maturity. Curve progression is often associated with degenerative intervertebral disc disease and degenerative joint disease of the spine in middle-aged or older patients or may be due to significant previously present undiagnosed or untreated scoliosis. Idiopathic scoliosis treatment is patient-age dependent. In patients with infantile scoliosis (0-3 years) left-sided curves are commonly seen, particularly in boys and may resolve spontaneously with growth (Fig.13). Observation treatment is done with repeat evaluation every four to six months. Use of orthoses (braces) and surgery is uncommon. Juvenile idiopathic scoliosis (3-9 year olds) may rapidly progress especially in children over the age of five and may require orthotic (brace) management (Fig.14). Surgery is indicated if the curve is unable to be controlled by orthotic means. Although surgery in a significantly skeletally immature spine will produce some decrease in ultimate spine height, it is better to have a shorter spine with more normal alignment than a progressive curve where height is lost because of deformity. The most common of all types of scoliosis is adolescent idiopathic and is seen with equal frequency in boys and girls at low curve magnitudes. Girls, for unknown reasons, have a significantly higher risk for development of curve progression than boys. Pulmonary and cardiac function are not impeded with lumbar curves and significant changes of pulmonary function are not seen in patients with thoracic curves until the curve reaches a level greater than 700 , i.e., a severe curve. This amount of curve and subsequent cardiac and pulmonary changes are often seen later in life in untreated idiopathic infantile and juvenile scoliosis patients and present a threat to life. Patients with adolescents onset idiopathic scoliosis do not usually have such compromise unless severe curves develop. The time of highest risk for curve progression in adolescent idiopathic scoliosis occurs around puberty, i.e., when the growth rate is the fastest. Pulmonary and cardiac function tests which require patient cooperation may be required to assess lung and heart function in some cases of severe scoliosis, especially pre-operatively.

In Depth Review of Scoliosis: Treatment of Adolescent Idiopathic Scoliosis

Figure 15 Brace types Figure 16 Radiograph of a patient with AIS undergoing brace treatment Figure 17a Radiograph of patient with AIS (Pre-op) Figure 17bc Radiograph of patient with AIS (Post-op)

Treatment choice in adolescent idiopathic scoliosis is determined by a complex equation which includes the patient's physiologic (not chronologic) maturity, curve magnitude and location and potential for progression. Thoracic curves are at higher risk for progression than thoracolumbar curves or lumbar curves. Patients whose curves are of consequential magnitude prior to onset of their adolescent growth spurt are at significant risk for curve progression. Treatment options include observation, bracing or surgery. General guidelines include re-evaluation every 4-6 months (often including a PA erect T-L spine radiograph) for patients who are skeletally immature (but still not fully skeletally mature) and have curves less than 250 . In patients who are more skeletally mature with curves less than 450 similar observation should be carried out to assess any evidence of interval change at 6 months. Brace (orthotic) management of adolescent idiopathic scoliosis is used in children with spinal deformity and curve magnitudes of 25-400 who are skeletally immature and with significant growth remaining. The primary goal of brace management is to stop curve progression. Any amount of curve correction at the end of brace treatment must be considered a "bonus." The orthoses used are usually underarm or higher reaching Milwaukee-type styles (Fig.15). The type of braces and amount of time the braces are worn daily vary according to the orthopaedist's choice (Fig.16). Brace removal for participation in sports is strongly encouraged. An alternative to full-time brace wear is the use of a night time "bending" brace for management of a single curve. The termination of successful brace use is determined by the achievement of skeletal maturation, usually indicated by the patient not having further changes in height (and no curve progression) and evidence of maturity on skeletal radiographs. Surgery for idiopathic scoliosis is suggested when curve magnitude is 500 or more in either the previously untreated patient or in one who fails brace treatment. Surgery is undertaken with two goals in mind. The primary one is to prevent spine deformity progression and the secondary one is to diminish spinal deformity. The natural history of idiopathic scoliosis during adulthood is one of continued progression if the curves tend to be more than 500 at the end of growth. The surgical procedure most often used to correct idiopathic adolescent scoliosis is a posterior spinal fusion with instrumentation and bone grafting (Fig.17). With current instrumentation techniques, post-operative casting and bracing are not required in most idiopathic scoliosis cases. Patients are rapidly ambulatory and usually discharged from hospital within 5-7 days postoperatively with progressive resumption of routine daily activities, including return to school (Fig.18). There is no scientifically documented role for exercises, manipulation or electrical stimulation in the management of scoliosis. Figure 18a Clinical photos of patient with AIS (Pre-op) Figure 18b Clinical photos of patient with AIS (Post-op)

In Depth Review of Scoliosis: Kyphosis - Abnormal

Figure 19 Clinical photo of kyphotic deformity in a 13yr-old boy with Scheuermann's disease Figure 21 14yr-old girl with Scheuermann's disease (radiograph T-L spine) Figure 22 Congenital kyphosis & scoliosis radiographs Figure 23 MRI: Congenital kyphosis due to formation defect with normal cord, roots. Figure 24ab AP and lateral adolescent AIS radiographs

Diagnosing Similar imaging guidelines exist as described for scoliosis. With the patient erect, radiographs are taken to show side-to-side alignment. Spinal radiographs are sometimes taken with the patient erect and supine are helpful to document flexibility of a rigid deformity. Specialized imaging studies (CT scan, MRI, bone scan) are used as required. Clinical Pertinent historical points include those previously mentioned for scoliosis assessment. Examination includes the forward bend test and the patient is viewed from the side to see if the normal spine contours are present (Fig.19). Prominence of the patient's thoracic kyphosis or failure to reverse their lumbar lordosis with bend requires further investigation. Postural "Round Back" Postural "round back" is defined as an increase in thoracic kyphosis while standing. Curve flexibility is seen when the patient "stands tall" or, when prone or supine, the "deformity" resolves (Fig.20). This non-progressive condition is commonly seen in middle school children, especially girls, and almost always resolves by itself and requires no specific treatment. Parental "nagging" should be avoided. Scheuermann's Disease Scheuermann's disease is a condition of unknown cause which produces an increased thoracic kyphosis (>400 ) with true structural changes within the thoracic vertebra with 50 of wedging in each of three adjacent vertebrae measured on side-view radiographs (Fig.21). This localized deformity is usually painless. Treatment is dependent upon the magnitude of the deformity, pain complaints and patient maturity. Observation is done for deformity of less than 600 and brace treatment for curves between 600 and 800 if the patient is skeletally immature. Surgery is rarely required. A subtype of Scheuermann's disease occurs in the lumbar spine, usually in male patients during late adolescence who are involved in heavy lifting tasks. The changes of the vertebra and disc are considered to reflect the physical stress effects. Treatment is by elimination of the offending activity. Congenital Kyphosis/Lordosis Sagittal plane deformities may be due to congenital defects of vertebral formation or failure of vertebral segmentation (Fig.22). Deformities due to congenital vertebral formation failure are predictably progressive and require early surgical treatment. Because of potential associated renal anomalies, renal ultrasonographic assessment is recommended. MRI of the spinal canal may also be needed to rule out associated spinal cord abnormalities (Fig.23). Summary Spinal deformity is due to a myriad of causes. Scoliosis, kyphosis and lordosis are descriptive and not diagnostic terms and efforts must be made to establish the deformity's cause. The etiology of the most common type of spinal deformity, adolescent idiopathic scoliosis, is unknown, but it is strongly familial. Initial radiographic examination for scoliosis requires a standing back-to-front (PA) thoracolumbar spine radiograph on a single film. Sagittal plane concerns are evaluated by side view radiographs (Fig.24ab). Treatment varies according to the deformity's cause, location, magnitude, patient maturity and evidence of progression. Treatment decisions are based on a complex equation taking such factors into account. Modern bracing techniques provide cosmetic braces which allow patients to continue their routine activities including sport participation. Modern methods of surgical management allow for patients' rapid mobilization and return to routine daily activity.