What Is Scoliosis?

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Scoliosis is an abnormal C-shaped or S-shaped curve of the spine that is usually diagnosed in childhood or early adolescence. Besides having an uneven waistline and/or one shoulder that appears higher than another, a person with scoliosis may look like they are leaning to one side. Rarely, severe cases of scoliosis may cause rib deformity and breathing problems. In most cases, scoliosis is permanent without medical intervention, although treatment is not always necessary.

when does scoliosis require treatment?
Verywell / Gary Ferster

Spine Anatomy

Your spine can be divided into three main parts—your neck (cervical spine), your chest and mid-back (thoracic spine), and your lower back (lumbar spine). Vertebrae are the bones that make up your spine, and they are stacked one upon the other like blocks.

When looking at your spine from the back, the vertebrae normally form a straight line. With scoliosis, however, the vertebrae curve to one side and rotate or twist, making the hips or shoulders appear lopsided and uneven.

While scoliosis can occur in any part of the spine, the thoracic and lumbar spines are the most commonly affected. Typically, a sideways curvature or "C" shape of the thoracic or lumbar spine forms. Less commonly, the spine may curve twice (once in the neck and once in the lower back) and form an "S" shape.

Scoliosis Symptoms

Here are some of the more common signs of scoliosis:

  • Uneven shoulders, arms, rib cages, and/or hips (meaning one is higher than the other)
  • A shoulder blade that sticks out farther than the other
  • The body may appear to be leaning to one side
  • The head may not seem like it is centered right above the pelvis

If scoliosis progresses, the spine deformity may press on adjacent nerves, leading to weakness, numbness, and electric shock-like sensations in the legs. Walking or posture abnormalities may also occur. Rarely, if the lungs are unable to expand due to ribcage deformity, breathing problems may occur.

Scoliosis does not generally cause severe back pain. If present, an evaluation for an alternative diagnosis is warranted.

Causes

Experts generally divide the causes of scoliosis into three main categories due to their underlying causes—idiopathic, congenital, and neuromuscular.

Idiopathic Scoliosis

Idiopathic scoliosis is the most common form of scoliosis; it accounts for around 85% of cases. The word idiopathic simply means that the precise cause is not known, although experts believe that genetics may play a role in some cases.

Idiopathic scoliosis is further classified by age group:

  • Infantile (birth to 2 years)
  • Juvenile (3 to 9 years)
  • Adolescent (10 years or older): This is the most common type of scoliosis. It occurs at the growth spurt of puberty.
  • Adult: A progression of adolescent idiopathic scoliosis

Congenital Scoliosis

Congenital scoliosis is rare and is the result of an abnormality of the development of the vertebrae. For instance, one or more vertebrae may fail to form or may not form normally.

Congenital scoliosis means that the bony abnormality is present at birth. However, the actual lateral curve of the spine (scoliosis) may not develop till later in life.

While congenital scoliosis may occur on its own, sometimes it's associated with other health issues, such as bladder, kidney, or nervous system problems.

Examples of such syndromes include:

Neuromuscular Scoliosis

Neuromuscular scoliosis develops as a result of an underlying nervous or muscular system disorder. The spine curvature occurs because various nerves and muscles cannot maintain proper spine alignment.

Examples of common conditions associated with neuromuscular scoliosis include:

Other

Besides idiopathic, congenital, and neuromuscular scoliosis, there are two additional categories that scoliosis may fit into:

  • Degenerative scoliosis is most common in people age 65 years or older and occurs as a result of the degeneration ("wear and tear") of the joints and discs of the spine. This type of scoliosis is most common in the lumbar spine (lower part of the back) and may be associated with back pain and nerve symptoms like tingling and/or numbness.
  • Functional scoliosis occurs when there is a problem with another part of the body that is making the spine appear curved, even though structurally it is normal. For example, a discrepancy in leg length can make the spine seem curved, as can muscle spasms and inflammation from appendicitis or pneumonia.

With functional scoliosis, once the underlying problem is fixed, the curve will go away. In other words, since the spine is normal, no specific spine treatment is ever needed.

Diagnosis

If you suspect you or your child has scoliosis, make an appointment with your primary care physician. You may then be referred to a doctor who specializes in spine disorders, like an orthopedic surgeon or a physiatrist.

The diagnosis of scoliosis is generally made from a medical history, physical exam, and one or more imaging tests.

Medical History

During the medical history, a doctor will inquire about your past medical history, family history, and when you first noticed problems with your (or your child's) spine. They will also ask about symptoms, including whether they cause any emotional distress and/or affect daily activities.

Physical Examination

During the physical exam, the doctor will carefully inspect the spine to determine whether there is any lateral curvature present, which means that the vertebral column curves or bends from side-to-side. This may be evident from observing an asymmetry of the hips or shoulders.

In addition to a lateral curvature, a doctor will also look for a rotational or twisting spine deformity, which is also present in scoliosis (although it's often more subtle).

In order to do this, a doctor will perform the Adam's forward bend test. During this test, you are observed from the back while you bend forward at the waist until your spine is parallel to the floor. The test is positive if an asymmetry is present, like if a rib sticks out on one side of the body (what's called a "rib hump.")

The next step, after inspection of the spine, is to use a tool called a scoliometer to determine the angle of trunk rotation (ATR). While you are in the same bent position, the scoliometer is run along your spine from top to bottom. If the measurement of the scoliometer is 10 degrees or greater, an imaging test is required.

A slight degree of lateral curvature of the spine is not necessarily abnormal. In fact, a lateral curvature of the spine that is less than 10 degrees is within the limits of normal.

Imaging Tests

Various imaging tests may be used to diagnose scoliosis. Doctors almost always start with an X-ray, where the Cobb angle—a measurement of the spine curvature—is calculated. A Cobb angle of at least 10 degrees is necessary to diagnose scoliosis.

Besides measuring the Cobb angle, imaging tests like a magnetic resonance imaging (MRI) of the spine may be used for better visualizing the spinal curvature and for diagnosing a specific type of scoliosis, such as degenerative scoliosis.

Children with congenital scoliosis may have an increased chance of having other body system abnormalities. Because of this, other imaging tests—such as an ultrasound of the kidneys or bladder (called a renal ultrasound) or the heart (called an echocardiogram)—may be recommended.

Treatment

Scoliosis treatment is a subject that has been the cause of great debate for many year. As such, and unfortunately, there is not a definitive course of action for all cases.

In addition, the treatment of scoliosis really varies from person to person, depending on factors like age, the severity of the curve, the likelihood of the curve worsening, and the impact the condition is having on a person's quality of life and daily functioning.

For instance, mild scoliosis generally requires no treatment. However, scoliosis that causes breathing problems does.

That said, the three main scoliosis treatment options are observation, bracing, and surgery.

Observation

Patients are observed when the curvature of the spine is minimal. The cutoff is debatable, but depending on the age of the patient, the stage of skeletal development, and symptoms, it is somewhere between 20 and 30 degrees of curvature.

Over this cutoff, more aggressive scoliosis treatment is usually pursued. When being observed, patients are seen by a spine specialist about every six months until skeletal maturity is reached.

Bracing

Braces can help control any worsening of spine curvature but do little to correct an existing deformity. Bracing is most effective for scoliosis treatment when used in children that are rapidly growing and have worsening scoliosis curves.

Surgery

Surgery is often the best options for more severe curves. Depending on the site of the curve, the degree of curvature, a patient's specific symptoms, and the type of scoliosis, different surgical procedures may be performed:

  • Spinal fusion is a procedure in which a surgeon fuses vertebrae in a more normal anatomic position.
  • Microdecompression is a minimally invasive procedure that helps relieve pressure on nerves. Since this procedure may worsen your curve, especially if you go into the procedure with a curve that is greater than 30 degrees, this type of surgery is generally done only at one vertebral level—not multiple levels.
  • Surgical stabilization entails using various instruments—screws, wires, anchoring hooks, and rods—to stabilize the spine so it can fuse in the right position.
  • Osteotomy involves removing and realigning vertebrae to allow for proper spine alignment.

For congenital scoliosis, a surgeon may recommend a type of surgery where growth rods are attached to the spine above and below the curve. These growth rods correct the spine as it continues to grow.

Other Treatment Options

Studies are investigating the effectiveness of many other scoliosis treatments, including electrical stimulationchiropractic manipulation, and physical therapy. However, the jury is still out on these therapies, as research backing up their effectiveness is lacking.

That said, for individual patients, one or more of these therapies may provide some relief.

A Word From Verywell

While it may seem alarming to hear that you or your child's spine has a side-to-side curve, it's important to remember that not every person with scoliosis needs treatment. Furthermore, scoliosis is not something you can prevent. For example, it is not caused by wearing a heavy backpack or maintaining poor posture.

Scoliosis should not limit your life plans, including playing sports, exercising, or getting pregnant. Have an open conversation with your doctor about your symptoms and how they are affecting your life.

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