The human spine has natural curvatures. In the frontal plane (looking at the patient from behind) the spine should be straight. Kyphosis affects the sagittal plane (looking at the patient from the side view). When looking from the side, the spine has normal curvatures. In the neck (cervical spine) and low back (lumbar spine) there is normally an inward curvature or sway back known as lordosis. In the thoracic spine there is an outward curvature known has kyphosis or hunchback. These curves normally balance out each other so that when the patient stands the spine is balanced with the head straight above the hips when viewed from the side. Standing in this position minimizes the effect of gravity and allows the patient to stand with the best posture and use the least energy when moving or walking [Figure 1].
The thoracic spine should have a gentle rounding of the curve 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 [Figure 2].
There are several types of kyphosis. The most common form of kyphosis is due to poor posture. Patients with postural kyphosis can conscientiously correct the curve by standing straight. For these patients, no actual structural abnormality of the spine is present. Patients with postural curve are treated with reassurance in that their curvature is unlikely to progress and appropriate posture and spinal alignment are reinforced.
Structural kyphosis refers to an increase in the curvature of the spine that is not related to posture or slouching. Patients with structural kyphosis cannot straighten the spine consciously. The most common type of structural kyphosis is Scheuermann's kyphosis. Scheuermann's kyphosis is most commonly diagnosed between the ages of 12 to 14 years of age. For more details on Scheuermann's kyphosis and its treatment, please refer to the specific section entitled Scheuermann's Kyphosis.
An increasing kyphosis can occur as the result of another problem or abnormality in the spine. Any condition that leads to a loss of the height in the front part of the spine can cause an increase in kyphosis. The most common causes are conditions such as vertebral fractures or disc degeneration. 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 the patient develops [Figure 3].
Figure 3: In patients with kyphosis, a loss of normal curvature causes an imbalance of the spine. The patient’s head begins to lean forward, away from the body and they may have trouble standing upright. This imbalance can cause muscle fatigue and pain.
Most patients with kyphosis do not require surgical intervention. 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. Also, physical therapy and spinal manipulation can be used by patients to treat their symptoms of kyphosis. These treatments can help to relieve the symptoms related to kyphosis, but do not usually cause a change in the actual structure of the spine.
Spine surgery for kyphosis reconstruction is recommended for patients whose curvatures continue to progress or cause symptoms despite non-operative conservative treatment. Surgery for correction of thoracic kyphosis is usually recommended for curves that have progressed and are larger than 80° to 90° when measured on x-rays. For kyphosis extending into the mid or lower back (thoracolumbar spine) surgery is recommended for curves that are larger than 60° to 70° of kyphosis. Surgery is also an option for patients who have disabling back pain or for patients whose limited kyphosis is leading to some compression of the spinal cord or nerves of the spine. Case Example: [Figure 4]
Figure 4: This patient is a 64-year old man with severe progressive kyphosis. He lost the ability to stand erect or to hold his head upright to look forward while walking. He suffered from severe neck, thoracic and low back pain even when taking heavy doses of pain medicine. The patient underwent staged spinal reconstruction with kyphosis correction with Dr. Good at the Virginia Spine Institute and has noted significant improvement in his pain after surgery. He is now able to stand up straight and look forward while walking. X-rays taken before surgery show >100° kyphosis from the neck down to the low back and x-rays after surgery show normal spinal alignment. Case note from Dr. Good: “This patient's condition was very severe and the surgery performed is not common; however, his story serves as an inspiring example of the power of spinal deformity surgery to help someone who is suffering from terrible pain and disability.”
The goal of spinal reconstruction surgery for patients with kyphosis is to decrease the patient's pain and to place the spine in a more natural position. Most commonly this surgery is performed through a posterior approach in the back of the spine. During the surgery, spinal implants including rods and screws are placed next to the spine. These implants are used to correct the spinal deformity and stabilize the spine in its new position while those segments of the spine fuse together or mend. These bones ultimately heal into one solid piece leading to spinal stability and preventing further progression. The physicians at the Virginia Spine Institute use bone graft harvested from the patient's spine as well as biologic protein to achieve spinal fusion. These techniques make it much more likely that the spine fusion will occur correctly. The physicians at the Virginia Spine Institute do not routinely harvest bone graft from the patient's hip or iliac crest as this leads to increased pain and prolongs recovery time.