What Are The Causes Of Kyphosis?

It is often called hunchback or humpback. Kyphosis, the medical term for an abnormally rounded upper back or the thoracic spine, is a common spinal abnormality.¹

The thoracic spine is made up of the middle 12 vertebrae of your spine. It has a natural curve in the 20-40 degrees range which varies from person to person. Anything more than that is often classified as kyphosis. In case of kyphosis, the upper back looks more rounded than normal.²

While in adolescents and young adults, kyphosis is largely postural, in adults, there are various other causes as well. Here is a detailed look at each cause.

Poor Posture

It is very common to see adolescents, especially teenage girls, slouching while sitting or standing. This is often referred to as postural kyphosis because it is a problem of poor posture and has very little to do with any abnormalities of the spine. For that reason, it can be corrected easily by paying attention to the posture. “Stand up straight” is all that the person needs to do. Postural kyphosis is rarely painful and does not cause further problems.³

Scheuermann’s Disease

Scheuermann’s disease or Scheuermann’s kyphosis is another type of kyphosis seen among children. Unlike postural kyphosis, this one is serious and is considered a developmental disorder which gets carried on to adulthood. Also known as juvenile kyphosis, juvenile discogenic disease or vertebral epiphysitis, here, the thoracic curve is usually between 45 and 75 degrees. Moreover, there will be a vertebral wedging of more than five degrees of a minimum of three vertebrae. These vertebrae take a triangular appearance. The disorder is also marked by Schmorl’s nodes, which are small herniations of intervertebral disc (the cushion between each vertebra), at the end of the affected vertebrae. Scheuermann’s, the Danish radiologist who recognized the problem first, believed that the disorder was due to the death of the cartilage of the spinal bone’s ring due to the lack of blood supply. While the exact reason is unclear, experts have come to the conclusion that some sort of damage to the growth area of the vertebrae starts the process. The abnormal growth that follows causes the excessive kyphosis.⁴

Congenital Disorder

Kyphosis could also be congenital, that is, you could be born with this spinal deformity. A deformity that is severe and catastrophic, there is no known treatment for congenital kyphosis.⁵

Congenital kyphosis is not genetic. It is believed that it happens sometime in the six to eight weeks of the embryonic life. Due to some genetic mistake at this phase, the front part of one or more vertebral bodies and disc fails to form or segment which causes the spine to develop a sharp forward angulation as it grows.⁶

Age-Related Hyperkyphosis

Kyphosis is often seen in old age. Also called Dowager’s hump or gibbous deformity, hyperkyphosis impairs mobility and increases the risks of fall and fractures. Though the exact cause is not known, hyperkyphosis could be the result of either muscle weakness and degenerative disc disease, leading to vertebral fractures and worsening hyperkyphosis, or from initial vertebral fractures that precipitate its development.⁷

Kyphosis From Diseases/Injuries

Kyphosis could also occur as a result of an injury or a spinal disease. Here are some instances.

From paralysis: Kyphosis can happen as a secondary result of paralysis. This paralysis could be from disorders like polio, spinal muscle atrophy, cerebral palsy, etc. Kyphosis does not happen immediately in these cases; it is more gradual.⁸

Post-traumatic disorder: Any trauma to the spine like an injury could result in kyphosis. Post-traumatic kyphosis could happen anywhere from mid to lower back. This kyphosis is often accompanied by severe pain in the region.⁹

Degenerative kyphosis: The kyphosis in the lumbar region of the spine, lumbar degenerative kyphosis is characterized by abnormal kyphosis in the lumbar region due to degenerative changes of the spine and supporting structures. In this case, the trunk stoops while walking and pain and dullness are noticed in the lumbar region. Patients will also find it impossible to lift their trunk up from the prone position. Vertebral wedging and multiple disk space narrowing are commonly seen in degenerative kyphosis. Lumbar extensors could also experience atrophy.¹⁰

Spinal infection: Any kind of serious spinal infection like spinal tuberculosis can lead to the kyphosis of the spine.¹¹ A spinal infection is rare and often involves the intervertebral disc space, the vertebral bones, the spinal canal, or adjacent soft tissues. These infections are mostly bacterial in nature and spread to the spine through the bloodstream.

Spinal cancer/tumor: Spinal deformities like scoliosis or kyphosis are one of the symptoms of a tumor in the spine. This tumor could be benign; it could be malignant too, in which case it will develop into cancer of the spine.¹²

Arthritis: Osteoarthritis is a degenerative form of joint arthritis. In the spine, it can affect the facet joints, the intervertebral discs, and the ligaments supporting the spine. In severe cases of spinal osteoarthritis, standing upright becomes difficult due to severe pain in the region. These can lead to changes in the structure and shape of the spine. Kyphosis could appear in the advanced stages of OA of the spine.¹³

Kyphosis can affect every facet of your life. It is not just another deformity, it could also be painful and uncomfortable. While certain kyphosis cannot be treated, some of them at least can be avoided with timely medical intervention. If you suspect changes in your spinal structure, do not delay consulting a medical expert.