- Clinical science
Idiopathic scoliosis is a deformity of the spine characterized by lateral deflection and rotation of the vertebral bodies. The disease typically presents in patients 10–12 years of age and is seen more commonly in girls. The most common pattern of scoliosis is a right convex curvature of the thoracic spine, resulting in forward rotation and protrusion of the right shoulder. Initially, patients do not experience any symptoms. The disease is often diagnosed incidentally or following manifestation of obvious skeletal deformities. Since scoliosis is a progressive condition, later symptoms can include pain and reduced mobility due to degenerative lesions of spinal discs and vertebrae. In severe cases of spinal deformity, patients may show signs of pulmonary restriction, including dyspnea and difficulty breathing. Scoliosis is a clinical diagnosis that is confirmed by typical findings on x-ray (e.g., Cobb angle > 10°). Treatment initially consists of observation and the use of braces. In cases of severe or rapidly progressing scoliosis, surgical treatment is necessary.
- Sex: ♀ > ♂ (∼ 5:1)
- Peak incidence: 10–12 years
- The spinal curvature deformity can progress in ∼ ⅔ of skeletally immature patients as they grow.
Epidemiological data refers to the US, unless otherwise specified.
- Exact etiology unknown; genetic factors are likely
- Mismatch in growth of dorsal and ventral parts of the vertebrae; : growth of vertebral arches lags behind that of vertebral bodies → impaired longitudinal growth with rotation of vertebrae; → lateral curvature of the spine
- Primary muscle or connective tissue disorders
- Abnormal growth hormone secretion
According to age
≥ 10 years: adolescent idiopathic scoliosis
- ♀ > ♂
- Most frequent type (∼ 80% of cases)
- Usually manifests as a right convex thoracic curvature
4–9 years: juvenile idiopathic scoliosis
- ♂ > ♀
- Usually manifests as a left convex thoracic curvature
- Deteriorates progressively
0–3 years: infantile idiopathic scoliosis
- ♂ = ♀
- Often manifests as a convex thoracic curvature with bending to the left
- Special type: congenital functional scoliosis ; usually heals spontaneously
- ≥ 10 years: adolescent idiopathic scoliosis
According to the apex of the major curvature
- Cervical: C2 to C6
- Cervicothoracic: C7 to T1
- Thoracic: T2 to T11
- Thoracolumbar: T12 L1
- Lumbar: L2 and L4
- Lumbosacral: L5 or below
- According to the pattern of the curvature: C-shaped scoliosis, S-shaped scoliosis, double S-shaped scoliosis (triple scoliosis)
- Patients present because of noticeable deformities, which are especially visible on physical examination.
- Evaluation of the spinal shape from the back of the head to the intergluteal cleft
- Adam's forward bend test (most important clinical test) may show ;:
- Assessment of severity based on scoliometer measurements (see “Diagnosis”)
- Respiratory and cardiopulmonary impairment in cases of severe thoracic deformity
- Pain occurs secondary to degeneration, compression, or irritation of spinal discs and nerves.
The elevated part of the rib cage and the lumbar hump are always seen on the convex side of the deformity! In the most common form of scoliosis, the right convex thoracic curvature results in forward rotation and elevation of the right scapula!
- Indicated to evaluate necessity for treatment (see “Treatment” below”); performed in cases of deviations > 7° on scoliometer measurements
Evaluation of the lateral curvature (in anterior-posterior projection, full-length views)
- Major curvature: highest deviation from the perpendicular
- Minor curvatures: compensatory deviations from the midline above and below the major curvature
Cobb angle: refers to the angle between the following lines
- 1. Perpendicular to a line drawn across the superior endplate of the highest affected vertebra
- 2. Perpendicular to a line drawn across the inferior endplate of the lowest affected vertebra
- Estimation of vertebral rotation (Nash and Moe method): assessment of the position of the vertebral pedicles is relation to the vertebral bodies
- Evaluation of skeletal maturity based on lateral ossification of the apophysis across the iliac crest (Risser sign) → relevant for prognosis
|Grade 0||Apophysis not yet identifiable|
|Grade 1||Ossification of apophysis ≤ 25% of the iliac crest|
|Grade 2||Ossification of apophysis ≤ 50% of the iiliac crest|
|Grade 3||Ossification of apophysis ≤ 75% of the iliac crest|
|Grade 4||Ossification of apophysis > 75% of the iliac crest|
|Grade 5||Fusion of the apophysis to the iliac crest|
Every school-aged child should undergo a physical examination of the spine in order to rule out scoliosis. Scoliosis is frequently an incidental finding!
- Congenital (e.g., unilateral fusion of L5 with the sacrum)
- Neuromuscular diseases; (e.g., muscular dystrophy, spina bifida, Friedreich ataxia)
- Metabolic diseases (e.g., rickets)
- Connective tissue disease (e.g., Marfan syndrome; , Ehlers-Danlos syndrome, osteogenesis imperfecta)
- Anatomic malformations (e.g., isolated difference in leg length, secondary to trauma or tumors)
The differential diagnoses listed here are not exhaustive.
- Treatment based on the Cobb angle
- 18 hours/day, if possible
- Bracing is usually able to halt progression, but cannot cure the underlying condition.
- Goal: correct spinal arching and rotation
- Various surgical techniques and approaches exist (ventral, lateral, dorsal, or combined approach).
- Spondylodesis: fusion of the vertebrae by bridge plating or by internal fixation
- Risks: paraplegia (< 1% of cases), development of pseudarthroses, infection of surgical material