The human spine has natural curvatures. When you look at the spine from behind, the spine should be straight and keeps the body centered over the pelvis. However, when you look at the spine from the side it has curves designed to maintain balance as the spine is located behind the organs in the chest and abdomen. The spine has two kyphotic curves and two lordotic curves which alternate to create an “S” like shape. In the neck and low back there is normally an inward curvature or sway back known as lordosis. In the thoracic spine and sacrum there is an outward curvature known has kyphosis or hunchback. These curves normally balance out each other so that when we stand we are well balanced with our head straight above our hips when viewed from the side. Standing in this position minimizes the effect of gravity and allows us to stand with the best posture and use the least energy when moving or walking.
Kyphosis affects the sagittal plane, or side view. The thoracic spine should have a gentle rounding behind the shoulders. Normal thoracic kyphosis ranges from 20° to 40° when viewed from the side. If the curvature grows larger than that, a kyphosis is present.
There are several types of kyphosis.
The most common form of kyphosis is from poor posture. Patients with postural kyphosis can conscientiously correct the curve by standing up straight. For these patients there is no actual structural abnormality of the spine and their curve is unlikely to progress.
Structural kyphosis refers to an increased curve of the spine not related to posture or slouching. Patients with structural kyphosis cannot consciously straighten the spine. Patients with kyphosis may notice difficulty with standing upright or have ongoing back or leg pain. Symptoms usually worsen as the day goes on and the patient will feel they lean further and further forward the longer they try to stand erect. The severity of the symptoms usually depends on the amount of kyphosis present.
The most common type of structural kyphosis is Scheuermann's kyphosis. It is most commonly diagnosed between the ages of 12 to 14 years of age. Scheuermann's kyphosis is a thoracic kyphosis measuring more than 40° with wedging of three or more vertebrae in a row. The cause of Scheuermann's kyphosis is unknown; however, researchers believe it is related to abnormal bone growth and development. This condition has a genetic predisposition and is most typically seen and diagnosed during periods of rapid bone growth such as in adolescence. Most patients first note poor posture or slouching and can develop pain in the increased curvature.
Kyphosis can occur from another problem or abnormality in the spine. Any condition that leads to a decreased height in the front part of the spine can cause an increase in kyphosis. Common causes stem from conditions such as compression fractures due to osteoporosis, other spinal fractures or degenerative disc disease.
Diagnosis is based on physical examination and x-ray evaluation. A full medical history is noted to rule out other potential causes of kyphosis. X-rays are used to evaluate the alignment of the spine and to measure the overall curvature when viewed from the front and back.
Scheuermann's kyphosis disease is diagnosed with thoracic kyphosis measuring more than 40° with wedging of three or more vertebrae in a row. If an MRI is ordered, patients commonly have Schmorl's nodes, small disc herniations through the endplates of the vertebra. These disc herniations are different than herniations that occur into the area where spinal nerves are located.
Treatment depends on the patient's age, the size of the curve, the symptoms the patient may be experiencing and the underlying cause of kyphosis. Most patients with kyphosis are first observed to see if the curve increases in size over time. During this time physical therapy and exercise programs improve posture and help strengthen spine muscles. For patients with mild kyphosis, formal treatment is not always required. For patients who have pain or stiffness from their kyphosis, a physical exercise routine including core muscle strengthening and aerobics can be beneficial. Physical therapy and spinal manipulation can be used to treat symptoms of kyphosis. These treatments can help relieve symptoms related to kyphosis, but do not usually cause a change in the actual structure of the spine.
For curves that progress, or in initially severe cases, a brace may be used to help straighten the spine and try to prevent further progression during growing years. Brace treatment for kyphosis is only used for patients who are still growing and is not an effective treatment for adult patients. Brace treatment for Scheuermann's kyphosis in growing adolescents is similar to bracing for patients with scoliosis, however, the location and type of the brace may vary depending on the location of the kyphosis. For patients who need a brace, a light weight thoracolumbosacral (TLSO) brace or Boston brace is most commonly used. This light weight brace is custom molded to the patient's body, can be worn under clothes and allows patients to still participate in most sports and activities. A TLSO brace is a lightweight plastic brace that is molded to fit a person with a spinal curvature. The goal of a brace is to keep the curve from getting bigger during the years of growth.
Most patients with kyphosis do not require surgical intervention. Spine surgery for kyphosis is recommended for patients whose curvatures continue to progress or cause symptoms despite non-operative treatment. Corrective surgery for thoracic kyphosis is usually recommended when curves are larger than 80° to 90° when measured on x-rays. Kyphosis can extend into the mid or lower back and in those cases surgery is recommended for curves larger than 60° to 70° of kyphosis. Surgery is also an option for patients with disabling back pain or when kyphosis leads to compression of the spinal cord or nerves. Learn more about surgical options.