Scoliosis

By admin On Oct 29, 2023

Ovid: 5-Minute Sports Medicine Consult, The

Scoliosis

Cherise Russo

Basics

Not a diagnosis but a description of a structural change in anatomy

Description

Lateral curvature of the spine measuring 10° of curvature by Cobb angle, usually accompanied by rotation
3 categories:
- Neuromuscular scoliosis develops in patients with neurologic or musculoskeletal abnormalities and may be structural or nonstructural.
- Congenital scoliosis is usually evident before adolescence and is a result of congenital asymmetry in the vertebrae.
- Idiopathic scoliosis is a diagnosis of exclusion; infantile (0–3 yrs) and juvenile (4–9 yrs) are considered early-onset, and children 10 yrs and older are considered to have adolescent idiopathic scoliosis (AIS):
  - AIS is the most common type of idiopathic scoliosis (80–85%).

Epidemiology

Generally considered 1.9–3% for curves exceeding 10°
Only 10% of adolescents with AIS require treatment: 0.3% of the population.
Males and females affected equally, but the risk of curve progression is 10 times higher in females.

Prevalence

Cobb angle 10–19°: 2–3%
Cobb angle 20–29°: 0.3–0.5%
Cobb angle 30–39°: 0.1–0.3%
Cobb angle >40° is ≤0.1%

Risk Factors

Etiology of AIS is unclear at this time.
Believed to be multifactorial
Genetics have been proposed to play a role.
Other proposed factors: Growth hormone secretion, connective tissue structure, paraspinal musculature, vestibular function, melatonin secretion, platelet microstructure

Genetics

2 studies show a higher concordance rate in the incidence of scoliosis in monozygotic twins vs dizygotic twins.
Chromosomes 17 and 19 have been identified as having genetic loci for AIS.
Inheritance pattern is not known.
Expression of familial AIS may be linked to the X chromosome, with a dominant inheritance pattern.

General Prevention

No prevention recommendations exist at this time.
Benefit of preclinical detection not proven at this time
U.S. Preventive Services Task Force recommends against the routine screening of asymptomatic adolescents for idiopathic scoliosis (1)[D].

Etiology

Lateral curvature of the spine with rotation
By definition, causes are unknown; listed are some theories, none proven in isolation.
Genetic:
- Positive familial history for scoliosis in 30% (not predictive for severity)
Connective tissue disorder:
- Platelet calmodulin levels may be predictive of curve progression.
Neurological (equilibrium system):
- Most widely supported theory
- Abnormalities noted in vestibular, ocular, proprioceptive, and vibratory functions.
Hormonal:
- Lower levels of melatonin secreted from pineal body in those with AIS.
- Growth-stimulating hormone: More of an influential factor than etiologic factor studies

Diagnosis

Neuromuscular scoliosis:
- Occurs in patients with neurologic or musculoskeletal conditions
May be seen with cerebral palsy, myelomeningocele, muscular dystrophy, or leg length discrepancy
Congenital scoliosis:
- Occurs from vertebral asymmetry secondary to congenital abnormalities
- Hemivertebrae, wedge vertebrae, failure of segmentation
- Usually manifests before adolescence
Idiopathic scoliosis:
- No definite etiology
Age 0–3 yrs: Infantile
Age 4–9 yrs: Juvenile
Age ≥10 yrs: Adolescent
Criteria for AIS:
- Age ≥10 yrs
- Curvature of spine in coronal plane that has a Cobb angle of ≥10°
- Exclusion of neuromuscular and congenital causes

Pre Hospital

Identify underlying etiologies
Assessment of the curve clinically
Determine need for radiographs
Determine risk of progression

History

Consider:

Onset: Consider when 1st noted, by whom, rate of worsening, previous treatment, associated signs or symptoms, familial history, etc.
Rate of progression: Rapid progression is suggestive of a nonidiopathic cause.
Pain: Patients with idiopathic scoliosis should not have pain.
Night pain: If pain, consider tumor such as osteoid osteoma or other tumor
Are there symptoms suggestive of neuromuscular etiology? Bowel or bladder problems? Muscle weakness? Headache? Neck pain?
- Neurologic symptoms increase likelihood of nonidiopathic causes.
Does the patient have difficulty breathing?
- Severe thoracic scoliosis may affect respiratory function.
Has the pubertal growth spurt started?
- Important for determining remaining linear growth and need for intervention
Has the patient entered puberty?
- Tanner grade 2 precedes the onset of pubertal growth spurt in boys. Tanner 2 follows the onset of pubertal growth spurt in girls.
Has menarche occurred?
- Pubertal growth spurt occurs just before menarche.
Is there a history of lower limb fracture, joint infection, or arthritis?
- This may result in a leg length discrepancy.
Is there a family history of scoliosis?
- A family history may suggest AIS.
Other signs or symptoms?
- Review of systems (especially neurological)

Physical Exam

Plot height and weight on growth curve.
Spine inspection, head should be balanced in line over the center of the sacrum
Assess Tanner stage (risk for progression is greatest during the pubertal spurt)
General inspection to look for skin changes such as:
- Café au lait, pigmentation, or other signs of neurofibromatosis, for example, dysraphic signs (hairy patches, etc.)
Assess for maturity, hyperelasticity, contracture, congenital anomalies.
Assess for deformity, symmetry of spine, symmetry of iliac crests, shoulders and trunk, including decompensation, abnormalities of thoracic kyphosis, or cervical or lumbar lordosis.
The Adam forward bending test is used to look for rib or paraspinous elevations, demonstrates rotational component
Assess for leg length discrepancy, congenital anomalies, and neurological abnormalities (including abdominal reflex).
Findings:
- Crankshaft phenomenon: Progression of curve size and rotation following posterior spinal fusion due to continued anterior spinal growth
- Patient is Risser 0, open triradiate cartilages, <10 yrs old, and is prior to the occurrence of peak height velocity (the time of maximum spinal growth).
  - Consider anterior fusion in addition to posterior fusion.
Physical examination tools:
- Scoliometer: To measure trunk rotation, an angle of 7° generally corresponds to Cobb angle of 20°.
  - Important note: Not all patients with radiographic scoliosis have trunk rotation.
- Abnormal abdominal reflex: May suggest intraspinal pathology, including syrinx

Diagnostic Tests & Interpretation

Lab

Usually not helpful unless to rule out associated metabolic conditions
Pulmonary function testing is useful preoperatively.

Imaging

Plain standing full-length PA and lateral scoliosis films on a long 3-foot x-ray cassette (2)[B].
Direction of curve labeled by convexity (left thoracic curves have been associated with nonidiopathic causes)

P.523

Location is identified by vertebra that is most deviated and rotated from midline.
Cobb angle, formed by the intersection of a line parallel to the superior end plate of the most cephalad vertebra that has the greatest tilt with the line parallel to the inferior endplate of the most caudad vertebra of the curve. Not proportionate to the severity.
Curve patterns are classified according to the King-Moe and Lenke classification systems.
Risser sign is a visual grading of the degree of ossification and fusion of the iliac apophysis (lower Risser grade indicates more growth remaining).
MRI is not routinely necessary, but indicated in patients with neurologic symptoms, early age of onset with rapid progression, and for abnormalities found on plain radiographs.
Renal US or IV pyelogram are for evaluation of patient with congenital scoliosis.

Differential Diagnosis

Scoliosis: Neuromuscular, congenital, idiopathic
Postural abnormalities
Leg length discrepancy
Pain that results in splinting

Treatment

Concepts for treatment are based on the severity of the deformity present and on the likelihood of progression:

Risk for progression:
- Gender: Females have a 3–10-fold increased risk for progression.
- Curve magnitude: Initial Cobb angles of 20–29° are more likely to increase by at least 5°.
- Curve pattern: Double and thoracic curves have a 3-fold increased risk of progression.
- Maturity (remaining growth potential): For example, the lower the Risser sign, the greater the risk for progression
Options for treatment include observation, bracing, and surgery.
Guidelines for management (3)[B]:
- Patients with trunk rotation <7° are followed every 6 mos and standing full-length PA views are repeated if trunk rotation increases.
- Cobb angles <20° may be observed every 6–8 mos; younger children and patients with curves closer to 20° should be followed more frequently.
- Risser sign 0–2 with Cobb 20–29° should be followed closely and brace if angle increases by 5° or more over 3–6 mos.
- Risser sign 0–2 with Cobb angles of 30–40° should be braced.
- Risser sign 0–2 with Cobb angles between 40° and 50° may be braced or considered for surgery.
- Risser sign 0–2 with Cobb angle >50° at time of diagnosis typically require surgical evaluation and intervention.
- Risser sign ≥3 should be followed for at least 1 yr past skeletal maturity with radiographs every 6–9 mos.
- Skeletally mature with Cobb angles <40° can be reassured and discharged
- Skeletally mature with Cobb angles between 40° and 50° are managed on an individual basis

Medication

Postoperative continuous epidural infusion helpful for pain control

Additional Treatment

General Measures

Bracing recommendation:

Does not correct curve, but may prevent further progression
Only indicated for skeletally immature
Indicated if patient has a Risser sign of 0–2 and Cobb angle of 30–40° at time of diagnosis
Indicated if patient has Risser sign of 0–2 and has progression of 5° or more over 6–8-mo period of observation
No need for bracing if skeletally mature or Cobb angle ≥50°
Thoraco-lumbar-sacral orthosis underarm brace is useful for most curves.
Cervico-thoraco-lumbar-sacral orthosis (Milwaukee brace) indicated for curves with apex above T8 and double thoracic curves
Braces should be worn for 23 hr/day until the end of growth.
After discontinuation of brace, monitor patient every 6–8 mos.

Referral

Trunk rotation angle >7° and inability to assess Cobb angle
Cobb angle between 20° and 29° in premenarchal girls and boys 12–14 yrs of age
Cobb angle >30°
Progression of Cobb angle <5°
Surgical referral for skeletally immature patients with curves ≥50°

Surgery/Other Procedures

Posterior spinal fusion (PSF) with instrumentation and bone grafting
Current implants are segmental as opposed to older Harrington rods.
Segmental instrumentation affords the surgeon a better option for positioning.
Thorascopic procedures utilized for restrictive anterior soft tissue barriers
Anterior spinal fusion and PSF is needed at times to prevent the anterior spine from continuing to grow after the PSF (crankshaft phenomenon).
Bony fusion is paramount; pseudoarthrosis or failure to fuse is a complication of surgery.
Sports restriction for 9–12 mos following surgery, and contact sport clearance should be assessed by surgeon.

Ongoing Care

Follow-up 2 yrs after onset of skeletal maturity.
Skeletally mature patients do not need routine follow-up if Cobb angle >40°; beyond 40° should be individualized.
Back pain associated with idiopathic scoliosis
Pain in 23% at time of initial evaluation (additional 9% during follow-up)
Of those with back pain, only 9% found to have identifiable cause, such as spondylolysis, Scheuermann, syrinx, disc herniation, tumor, tether cord
Increased suicidal thoughts and self-image concerns among patients; address on individual basis
Pregnancy does not impact curve progression, nor does curve progression affect pregnancy outcome.

Prognosis

Risk of curve progression is related to patient's maturity (Risser sign, menarcheal status) and to the size of the curve.
Curves l <20–25° have a low risk of progression, even if patient is Risser 0 or Risser I.
Curves 25–45° have higher risk of progression, particularly in the immature.
Curves >45–50° have much higher risk of progression, regardless of maturity.
Overall, good prognosis for the majority of patients

Complications

Reduced pulmonary function for patients with thoracic curves >60°
Progression of lumbar curves >50° in adult life with degenerative disc disease and pain
Psychosocial factors
No increased mortality rates compared with general population

References

1. U.S. Preventative Task Force. Screening for idiopathic scoliosis in adolescents: recommen-dation statement. Am Fam Physician. 2005;71: 1975–1976.

2. Scherl SA. Clinical features; evaluation; and diagnosis of adolescent idiopathic scoliosis. www.uptodate.com. May 21, 2009.

3. Scheral SA. Treatment and prognosis of adolescent idiopathic scoliosis. www.uptodate.com. June 9, 2009.

Additional Reading

Greiner KA. Adolescent idiopathic scoliosis: radiologic decision-making. Am Fam Physician. 2002;65:1817–1822.

Reamy BV, Slakey JB. Adolescent idiopathic scoliosis: review and current concepts. Am Fam Physician. 2001;64:111–116.

Weinstein SL. Adolescent idiopathic scoliosis: prevalence and natural history. Instr Course Lect. 1989;38:115.

Codes

ICD9

737.30 Scoliosis (and kyphoscoliosis), idiopathic
737.31 Resolving infantile idiopathic scoliosis
737.32 Progressive infantile idiopathic scoliosis