USC Spine Center
Scoliosis & Kyphosis
Scoliosis refers to an S-shaped or C-shaped spinal deformity in the coronal plane (when looking directly at the person).
Kyphosis is used to describe the condition of increased forward spinal angulation in the sagittal plane (looking at someone from the side).
Patients may develop scoliosis or kyphosis spinal deformities in adulthood, or the deformity may have been present since childhood and become progressively worse. Generally, a mild scoliosis and/or kyphotic curvature does not cause significant pain or disability. However, when the deformity is progressive and/or associated with other spinal conditions, it may cause significant pain and disability, and require extensive treatment.
There are many causes of adult scoliosis and kyphosis. The most common cause of scoliosis is degenerative spinal arthritis, which can cause slight instability and eccentric loading of the spine, causing it to curve. This is referred to as de novo degenerative scoliosis (DDS). Most often, the curvature is mild and does not, in and of itself, require treatment. Other patients may have had scoliosis as a child. This is referred to as adolescent idiopathic scoliosis of the adult (ASA). Natural history studies have demonstrated that many patients, especially those with a curvature greater than 50 degrees in childhood, tended to increase at nearly 1 degree per year even after puberty. Adults may also present with scoliosis or kyphosis that was also present in childhood due to a congenital spinal abnormality.
The most common cause of adult kyphosis is osteoporosis compression fractures, yet this is typically a mild deformity unless there are multiple fractures. Other patients develop kyphosis because of degenerative spondylosis (arthritis of the spine) or due to post-surgical changes. Some patients have kyphosis due to Scheuermann's disease that was present since childhood, and others have a postural kyphosis.
There are other musculoskeletal conditions and neurologic diseases that can also cause scoliosis and kyphosis, such as pelvic obliquity, leg length discrepancy, and polio.
Pain and difficulty walking and standing are the most common symptoms of patients with a severe spinal deformity. Patients often feel as if they are "off balance," which occurs because their head and torso is frequently shifted forward and/or to the side. Patients may also have sciatica, neurogenic claudication, and leg symptoms if there is associated spinal stenosis.
The most prominent finding on physical examination is the spinal deformity and truncal shift, either in the coronal plane or sagittal plane, or both. Patients with scoliosis from childhood will often have a marked rib hump and rotational deformity of the rib cage. There may be spinal tenderness and spasm. Patients with significant spondylosis will often have decreased range-of-motion of the lumbar spine. The neurologic examination is usually always normal unless there is neurologic compression. This may occur with severe spinal stenosis, disc herniation, or rarely because of tumor or infection.
X-rays are the most important imaging study to obtain when evaluating scoliosis. Long plate, tri-fold anteroposterior (AP - x-ray is taken facing the patient directly) and lateral (x-ray is taken from the side view) x-rays should be taken with the patient standing in order to adequately evaluate a spinal deformity - both scoliosis and kyphosis. Side-bending x-rays are also obtained to understand how flexible a spinal curvature is before surgery is undertaken. A magnetic resonance imaging (MRI) test may also be indicated if there is concomitant degenerative disc disease, spinal stenosis, or other abnormalities. A computed tomography (CT) scan with or without a myelogram may also be required to adequately evaluate the presence of stenosis or neurologic compression.
There are no laboratory tests used to diagnose scoliosis and kyphosis. Occasionally, specific tests are ordered to rule out infection or other medical/rheumatologic conditions.
The diagnosis of scoliosis and/or kyphosis may be suspected, particularly if the above-mentioned physical findings are present. An x-ray is required to confirm the diagnosis, as well as to evaluate the severity of the deformity and curvature. Occasionally, patients may have another musculoskeletal abnormality, such as pelvic obliquity or a leg length discrepancy that is the underlying cause of the spinal deformity, and care must be taken to identify these other causes so as to render treatment appropriately.
The treatment of adult patients with scoliosis and/or kyphosis depends on the severity of the pain, nerve compression, and spinal deformity. A patient's age and general medical condition also is an important consideration, since the surgical treatments are often large operations. Nearly all patients are recommended for conservative treatment initially unless there is a severe neurologic deficit such as leg weakness and numbness. Physical therapy, chiropractic care and oral medications (non-steroidal anti-inflammatory medications, pain medications, and muscle relaxant medications) are frequently prescribed. Epidural steroid injections and/or nerve root blocks may also be utilized for severe pain or moderate pain that is no longer responding to other conservative measures. Patients who fail these conservative measures are usually candidates for surgical intervention.
A critical aspect of surgical decision-making is to determine what is causing the patient's pain and disability. Sometimes, a scoliosis patient may have one focal region of nerve compression or stenosis, which may be relieved by a small microscopic decompression surgery without correction of the spinal deformity. However, if there is significant spinal imbalance causing difficulty walking and standing, a deformity correction should be performed so as to address this problem. The surgical treatment of adult scoliosis and/or kyphosis is spinal fusion (mending the spine bones together) with instrumentation (metal rods and screws). A correction of the deformity is necessary if there is spinal imbalance or uncompensated curvature in either the coronal or sagittal plane. To put it simply, the patient's head should be balanced over the sacrum and pelvis when looking at the patient from the front view and the side view. The spinal curvature in the adult is rarely as flexible as that of a child or adolescent, therefore an anterior discectomy and release (incision through the stomach area or chest area) or a posterior osteotomy (cutting through the spine bone using the back incision) must be performed to facilitate adequate correction of the deformity.
The success rate of surgical correction is quite high if coronal and sagittal balance is achieved and a solid fusion is obtained. In 1999, Bradford reported that nearly 90% of patients were satisfied with their surgical results for adult scoliosis surgery. Although the risks of complications of scoliosis surgery are higher for adults than for children, most of the complications that do occur resolve and do not prevent the patient from achieving a satisfactory outcome.
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