Types of Kyphosis
Kyphosis is a description of one of the spinal curves you should see when looking at the spine from the side. Your mid-back, or thoracic spine, should curve outward. Your pelvis region should also curve outward; your neck and low back have an inward curve, also known as lordosis. You can learn more about these curves in the Anatomy of Kyphosis article.
However, you can develop too much of a kyphotic curve, especially in your thoracic spine. That's hyperkyphosis, a name usually (and somewhat confusingly) shortened to just kyphosis.
There are several types of kyphosis. This article will break them out for you. The type of kyphosis determines the treatment plan your doctor develops for you.
If you can correct the hump in your back, then you most likely have postural kyphosis. As the name implies, it's related to poor posture. The hump in postural kyphosis is very round and smooth.
A hump caused by structural kyphosis can't be corrected just by thinking about your posture. Structural kyphosis involves a problem with a part of the spine, such as a deformity in the vertebrae. The hump caused by structural kyphosis is much more angular than a hump caused by postural kyphosis. A particularly sharp, angular curve is called a gibbus deformity. In diagnosing structural kyphosis, the doctor will look for a gibbus.
Structural kyphosis is further divided into two types:
- Primary Structural Kyphosis: This type of kyphosis isn't caused by another condition.
One type of primary structural kyphosis is congenital kyphosis. That means that you're born with defects in the spine that cause it to curve too much. Often, heart and kidney problems are associated with congenital kyphosis because the spine, heart, and kidneys develop around the same time (third to sixth week of pregnancy).
The best example of primary structural kyphosis is Scheuermann's kyphosis, also known as Scheuermann's disease or juvenile kyphosis. It affects adolescents, and it develops when the front of the vertebrae don't grow as quickly as the back of the vertebrae. Instead of being rectangular, they become wedge shaped, and the spine starts to curve too much.
Doctors diagnose Scheuermann's kyphosis based on the following criteria: the kyphotic curve is greater than 50º, at least three adjacent vertebrae are wedged by at least 5º per vertebra, and there are small disc herniations called Schmorl's nodes.
- Secondary Structural Kyphosis: This type of kyphosis is caused by another condition. For example, osteoporosis in the spine may weaken to the vertebrae to the point of fracturing. The spine can then curve outward too much because it has structural problems. Osteoporosis is the primary condition; kyphosis is the secondary condition caused by the primary condition.