Kyphosis, the rounding of the back or the presence of a hump, may be clearly visible in moderate to severe cases. Mild cases may be harder to diagnose. Getting an accurate diagnosis of kyphosis starts with a doctor getting a complete medical history, including reviewing past X-rays for comparison, in addition to watching a person move in various positions and learning about the following:
- Onset of symptoms, or when the rounding of the spine was first noticed
- Changes in a person’s height
- Family history, since some types of kyphosis tend to run in families
- Bowel or bladder dysfunction, which may indicate nerve damage
- Pain, what intensifies it, and if any pain radiates from the spine itself, as well as tingling, numbness, impaired reflexes, and muscle weakness, indicating compression of nerves
- Past surgeries, as kyphosis can be a result of previous back surgeries. Iatrogenic kyphosis (caused by prior medical treatment) — such as when a spinal fusion does not heal properly and the ligaments are not strong enough to support the spine, which causes the vertebrae to collapse — often requires a second, revision surgery to correct the kyphosis. Post-laminectomy (surgery to relieve pressure on the spine) kyphosis is the most common type of iatrogenic kyphosis. A very common cause of kyphosis in the cervical spine, or neck, is iatrogenic.
X-rays are usually ordered to visualize the spine and confirm the diagnosis, as well as to determine the extent of the curvature. These and the following tests may be ordered to diagnosis kyphosis and its severity and cause:
- X-rays from different angles can be compared and checked for changes from past X-rays to determine progression of the curve (a curve that is greater than 45 degrees is considered abnormal) or visualize any other bony abnormalities.
- Front-view full-length X-rays of the spinal column are taken as the individual stands with arms extended forward while keeping the head erect.
- Lateral-bend X-rays may be taken from the side while an individual is bending sideways or backwards to visualize wedging of the vertebrae and determine flexibility.
- Traction-film X-rays are taken while an individual’s spine is pulled and held in a particular position and are ordered only occasionally.
- Computerized tomography (CT) is a noninvasive procedure that uses X-rays to produce a three-dimensional image of the spine. A CT shows more details than an X-ray and can reveal the nerves, spinal cord, and any possible damage to them.
- Magnetic resonance imaging (MRI) uses magnetic fields and radio-frequency waves to create an image of the spine that reveals the discs, nerves, spinal canal, and other details that can’t normally be seen on an X-ray. An MRI may also be used to check for spinal cord compression. Sometimes a contrast agent is injected into a vein in the hand or arm during the test, which highlights certain tissues and structures to make details even clearer.
- Myelograms involve a dye that is injected directly into the spinal column and are used in conjunction with CT scans.
- Electromyogram and nerve-conduction studies (EMG/NCS) measure the electrical activity in the nerves and muscles. They may identify nerve damage or nerve compression.
- Blood may be tested for the HLA-B27 gene, which is carried by more than 95 percent of those with ankylosing spondylitis, a form of arthritis in which chronic inflammation causes stiffness and pain in the spine.
- Pulmonary function tests may be ordered to determine if lung function is restricted due to decreased space in the chest from the kyphosis.
Reviewed by: Kai-Ming Fu, MD, PhD
Last reviewed/last updated: August 2021