How is scoliosis diagnosed?
How does my spine work?
In order to understand how scoliosis affects the body and how a doctor will examine the spine for the presence of the condition, one needs to understand the way in which the spine works.
The spinal column is divided into three different sections of vertebrae, these include:
- Cervical (C) vertebrae – These consist of seven spinal bones that support the neck.
- Thoracic (T) vertebrae – These consist of 12 spinal bones connecting to the rib cage.
- Lumbar (L) vertebrae – These consist of the five largest and lowest bones of the spinal column.
When scoliosis occurs, it may develop in the following ways:
- As one single curve – This curve has a C-shape and is known as a single primary side-to-side curve.
- As two curves – These curves consist of one primary curve as well as an additional compensatory secondary curve which together form an S-shape.
The severity of scoliosis will be determined according to the extent of the spinal curve/s present, as well as the angle of trunk rotation, also known as ATR. Curves that are less than 20 degrees are usually considered mild. When they progress beyond this degree of curvature, then they may require medical treatment.
Scoliosis diagnostic process
If scoliosis is suspected, a medical examination is required. A doctor is likely to ask a number of questions, some of which may revolve around family history of the condition, whether any weakness or pain is being experienced and if any other medical conditions exist.
A physical examination will involve examining the curve of the spine from the front, back and side. It is usually necessary for the patient to undress from the waist up in order for a doctor to get an accurate view of the spine’s curvature, and detect any abnormal curves, an uneven waist or any physical deformities.
The person being examined will be asked to bend over and try to touch their toes. This position helps to make any abnormal curves more visible. The doctor will also examine the symmetry of the patient’s body and try to see if the shoulders and hips are at the same height or if they have any sideways curvature or are leaning to one side. A doctor may also check muscle strength, range of motion and reflexes.
If any noticeable changes in the skin are evident, for example, café au lait spots, which are the colour of milk and coffee, this may suggest that scoliosis, if present, is the result of a birth defect5.
Identifying spinal curvature
Obtaining an accurate diagnosis when suffering from scoliosis is vital as a misdiagnosis may lead to unnecessary X-rays and stressful treatment for children who are not at risk of the disorder progressing. Although measurements of spinal curves are useful, there is no actual test to determine whether curvature will progress or not4.
A doctor may use an instrument known as an inclinometer (sometimes referred to as a scoliometer) to measure any distortions of the torso (while the patient bends over with their arms dangling in front of them). This device will be placed on the back to measure the apex of the upper back curve. This will be done on the lower back as well. These measurements will be repeated twice with the person being examined returning to a standing position between measurements.
Although scoliometers are a helpful way to measure and identify curvature, they are not accurate enough to guide treatment.
Doctors will group the curves of the spine by their shape, location, cause and pattern. This information will then be used to identify how best to treat a patient’s scoliosis.
- Shape – This refers to whether the curve is an “S” or “C” shape.
- Location – In order for a doctor to identify a curve’s specific location, he or she will determine the apex of the curve, this refers to the vertebrae within the curve that are the most off-centre. The location of the curve’s apex is the position of the patient’s curve. A curve that is thoracic, will have its apex in the area of the spine where the ribs attach, known as the thoracic area. A lumbar curve will have its apex in the lower back. A curve that is thoracolumbar has its apex where the lumbar and thoracic vertebrae meet.
- Pattern – Curves follow specific patterns. The larger the curve, the more likely it is to progress (depending on the amount of growth that is remaining).
Defining scoliosis according to the shape of spinal curvature
Scoliosis will often be categorised by the shape of the spinal curve present, this can be either of the following:
- Structural scoliosis – This classification of scoliosis involves the vertebrae rotating and twisting the spine in addition to the spine developing a side-to-side curve. As the spine begins to twist, one side of the rib cage will be pushed outwards to allow for the spaces between the ribs to widen, this leads to shoulder blade protrusion, creating a hump or rib-cage deformity. In addition, the other half of the rib cage will be twisted inwards, thus compressing the ribs.
- Nonstructural scoliosis – This involves the spinal curve being a simple side-to-side curve and not twisting.
As previously mentioned, a doctor will also look for other abnormalities of the spine that may occur alone or in combination with scoliosis, these include:
- Hyperkyphosis – This refers to the abnormal exaggeration of the outward rounding of the upper spine.
- Hyperlordosis – This refers to the exaggerated inward curving of the lower spine, also known as swayback.
X-ray evaluation (screening tests)
A doctor may suggest that an X-ray be done if a patient suffers from significant spinal curvature and a doctor suspects scoliosis, abnormal back pain or presents with any signs of the involvement of the central nervous system (this refers to the brain and spinal cord), such as bladder and bowel control issues. These abnormalities will usually be detected during a physical examination and discussion of symptoms.
An X-ray will be conducted with the patient standing with their back facing the X-ray machine. An image of the entire spine will be created.
Measurements can be made from the X-rays obtained and help a doctor to determine the size of the curve present. This will guide him or her regarding whether treatment options are necessary and which of these to consider. X-ray images can also be used as a point of reference during future visits and to identify any changes due to curvature progression if further X-rays are conducted in follow-up consultations.
If a doctor detects any changes in the functioning of the nerves, then he or she may conduct other imaging tests of the spine such as an MRI (magnetic resonance imaging) or CT (computerised tomography) scan to get a closer look at the vertebrae and spinal nerves.
The more growth that an adolescent or a child with scoliosis has remaining, the higher the chances of the condition progressing. Because of this, a doctor may also measure a patient’s weight and height and compare these statistics during future visits. There are other clues that can indicate the amount of growth remaining, these include signs of puberty such as the presence of pubic hair, the development of breasts and if a girl has started her menstrual period.
A doctor may perform additional X-rays of the wrist, hand or pelvis to determine how much growth a patient still has to do.
4. The University of Rochester. Scoliosis. Available: https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=85&contentid=p07815 [Accessed 05.09.2017]
5. Niams. 2002. Scoliosis in children and adolescents. Available:https://www.niams.nih.gov/health-topics/scoliosis [Accessed 06.09.2017]