Juvenile idiopathic scoliosis
Juvenile idiopathic scoliosis
ANATOMY OF THE SPINE
The human spine is formed by individual vertebrae and connective tissue discs in between. The vertebrae form the spinal canal. There are seven cervical, twelve thoracic, and five lumbar vertebrae. The intervertebral discs are the link between the individual vertebral bodies.
Normal anatomy of the spine. Longitudinal section and cross sections through the cervical, thoracic and lumbar spine.
The little joints that link the vertebrae together are known as facet joints. They help to stabilize the spine and, together with the intervertebral discs, allow a certain degree of mobility of the spinal cord. The spinal canal should be wide enough to allow nerve roots to float freely in cerebrospinal fluid.
The front border of the spinal canal is built by the vertebral bodies and intervertebral discs, the side by the intervertebral joints (facets) and back by the ligamentum flavum (yellow band) and vertebral arches. Discs consist of an outer fibrous ring (annulus fibrosus), which surrounds an inner gel-like center (nucleus pulposus).
The spinal cord and nerve roots lie within the spinal canal. The spinal cord extends downwards approx. to the 1st lumbar vertebra. Below, only nerve roots are present in the spinal canal. At the level of the intervertebral disc the nerve roots pass through the neural root foramina to exit the spinal canal. The spinal cord and nerve roots conduct electric-like signals from the skin and joints to the brain, and process of movement is initiated from the brain to the muscles.
Juvenile idiopatic scoliosis occurs between the 4th and 10th years and affects most of the thoracic and lumbar spine. The causes of development of juvenile scoliosis are not known. Genetic factors, accelerated growth and body posture might play a role. Often associated with plagiocephaly, congenital defects, neural axis abnormalities, thoracic insufficiency syndrome. Often associated with neural axis abnormalities, syringomyelia, Arnold-Chiari syndrome, tethered cord, dysraphism, spinal cord tumors. Juvenile scoliosis has a high risk of progression. About 70% of the patients require treatment (50% bracing, 50% surgery). Spontaneous resolution is rare.
CAUSE OF SYMPTOMS
Gradually progressing compression of nerve roots
Gradually progressing deformation of the spine
Gradually progressing inflammation and degeneration in the intervertebral joints
SYMPTOMS AND SIGNS
Total/partial paralysis and numbness from the site of the spinal cord damage downwoads
Visible spine deformity
Chest deformity (protrusion on one side and concavity on the other)
Waist asymmetry and pelvic tilt
Shoulder height differences
Inclined head position
Pain and stiffness along the spine
THE DIAGNOSIS IS BASED ON Medical history Clinical exam Radiographs Magnetic resonance imaging (MRI) Spirometry
The treatment may be non-surgical or surgical.
Non-surgical treatment may include
Observation: Cobb angle <20°
Bracing: Cobb angle 20° 50°
Goal to stop the progression, not to correct the deformity
Thoracic hypokyphosis is a relative contraindication
WHEN SHOULD AN OPERATION BE PERFORMED?
Cobb angle >50 °
The scoliosis angle increases
There is an abnormal sagittal profile
WHAT IS THE GOAL OF SURGERY?
HOW IS SURGERY PERFORMED?
Non-fusion procedures (e.g. growing rods) in small children, allow for continued spinal growth.
Anterior/posterior spinal fusion in younger patients, prevents crankshaft phenomenon.
Posterior spinal fusion (most performed) in patients near skeletal maturity
Anterior spinal fusion thoracolumbar and lumbar cases with a normal sagittal profile
WHICH OTHER DISEASES SHOULD BE EXCLUDED (DIFFERENTIAL DIAGNOSIS)? Congenital scoliosis Neuromuscular scoliosis Syringomyelia Spina bifida Tethered cord syndrome
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