A healthy human spine has a gentle curvature that optimally distributes our body weight, allowing us to walk, bend, stretch, and rotate. An excessive or distorted curvature, or spinal deformity, redistributes body weight in a way that can cause pain, limit mobility, reduce range of motion, and force other structures, such as the pelvis, to compensate. A spinal deformity may be evident at birth or develop during adolescence. We’ll confine our discussion to curvatures that develop during adulthood. This phenomenon is sometimes called adult spinal deformity (ASD).
What is a spinal deformity?
Spinal deformity is an umbrella term covering an extensive list of diagnoses associated with irregularities in the shape or curvature of the spine. Depending on their shape, location, and direction, these curvature disorders are known as scoliosis, lordosis, or kyphosis:
- Scoliosis is an abnormal S- or C-shaped sideways curve.
- Lordosis is an exaggerated front-to-back curvature affecting the lumbar, thoracic, or thoracolumbar spine.
- Kyphosis is an abnormally convex (rounded), humplike curvature, usually affecting the cervical spine.
How common is spinal deformity?
The incidence of spinal deformity varies, depending on its cause. Overall, this phenomenon is increasing as the nation’s 11 million Baby Boomers reach age 60. In fact, the average age of a patient undergoing surgery for spinal deformity is 59½ years. Six in 10 patients are women, and eight in 10 are white.1 These statistics suggest that women and whites are more likely to develop spinal deformities; however, people in these groups might simply be more likely to receive treatment.
What causes spinal deformity?
Spinal deformity is characterized by degeneration, misalignment, or malformation of spinal structures. Scientists are investigating various genetic predispositions, and disorders such as osteoporosis (fragile bones), osteopenia (low bone mineral density), degenerative disc disease, and arthritis are associated with the development of spinal deformity. But usually no cause can be found, and the disease is said to be idiopathic.
What are the symptoms of a spinal deformity?
The cardinal symptom of spinal deformity is back and leg pain.2 This pain often intensifies over the course of the day, as you become fatigued. You may also be stiff in the morning or have pain when walking. Some patients are unable to walk at all.3
Your doctor will probably ask you to rate your pain at each visit. This rating is subjective. A patient with severe, disabling pain might give it a 5 or 6 out of 10, while a patient with only moderate pain might report a score of 8 or 9. The purpose of this rating, though, is not to compare patients to each other, but to compare your own scores over time. In other words, asking you to rate your pain will help your doctor gauge how well your treatment is working.
How is spinal deformity diagnosed?
Your doctor will ask about your medical, family, and social history; perform a thorough physical examination to determine your range of motion; measure your height and weight; and ask about your activities of daily living (ADLs). Treatment becomes more urgent if your spinal deformity is making it hard for you to perform simple tasks like grocery shopping, cooking, or showering.
Documenting spinal curvature
When you get a blood test for diabetes, the lab returns a value—let’s imagine your blood sugar level was reported to be 170. This value means nothing unless you know that the normal range for blood sugar is 70 to 140. Thus a level of 170 may indicate that you have diabetes.
Likewise, your spine doctor must not only measure your spine, but also figure out how much its curvature deviates (that is, departs or diverges) from the curvature of a healthy spine. Your spine, of course, can be examined by the doctor. X-rays, too, are important in diagnosing spinal deformities. But is there such thing as a standard spine against which your spine can be compared?
Well, yes and no. It would do no good to compare your spine with that of, say, a 6’1″ man unless you’re a 6’1″ man. Instead, by dividing your body into imaginary planes (flat slices), the doctor can determine the natural position and curvature of your own spine and construct picture of what it would look like if it were healthy.
Analyzing the spine in three dimensions
Your physician will analyze your spine not just by itself, but also relative to the position of other structures, such as the pelvis. That’s important, since the body may compensate for a spinal deformity by recruiting other structures for help in walking, weight bearing, and the like. This compensatory mechanism may affect the tilt of the pelvis or the flexion of the hips, knees, or ankles.
Slicing and dicing the body into different imaginary planes, or layers, makes it easier for doctors to measure various three-dimensional angles and positions:
- The coronal plane splits the body in half from front to back.
- The sagittal plane splits the body into left and right halves.
- The transverse plane slices a cross-section through the body.
Notice that all of these planes create right angles—perfectly straight L shapes or T shapes. The doctors can then measure the amount of deviation from any of these straight lines.
In the past, your doctor would simply have formed a mental picture of the geometry of your spine. Perhaps he or she would’ve jotted down a few angles and measurements, or even made a little sketch. But thanks to advances in biocomputing, your doctor can now create a 3D rendering of your actual and ideal spine. This electronic model of your anatomy is invaluable in surgical planning.
Classifying spinal deformities
The Scoliosis Research Society (SRS)–Schwab classification system categorizes spinal curvature using a letter system:4
T = Thoracic only
L = Thoracolumbar only
D = Double curve
N = No curve
We’ve oversimplified this system here—it also includes a series of precise modifiers to indicate global alignment, identify the angle of pelvic tilt, and so on. The important thing to know is that the SRS–Schwab designations are widely used in diagnosis and surgical planning.
How are spinal deformities treated?
The treatment of a spinal deformity depends on the specific diagnosis, its severity, the patient’s age and comorbidities (coexisting chronic conditions), its rate of progression, and other factors.
Medications, along with heating pads and ice packs, are frequently recommended to relieve the pain associated with spine deformities. But treatment always targets the underlying deformity, not just its signs and symptoms.
Physical therapy is often used in the management of spinal conditions. The goal of therapy is usually to strengthen the musculature surrounding the spine, thereby strategically redistributing some of the spine’s workload. In patients with spinal deformity, biofeedback may be helpful to improve posture.
For pain relief, your doctor can recommend over-the-counter pain relievers or prescribe effective non-opioid medications, including nonsteroidal anti-inflammatory drugs (NSAIDs). In addition, certain antidepressant agents are useful for pain management even in patients without depression. Opioid (narcotic) pain relievers may be prescribed if necessary, depending on your diagnosis and medical history.
Doctors sometimes prescribe specially fitted braces to reduce pain by immobilizing the spine and supporting trunk muscles. Little reliable scientific research is available on the effectiveness of using back braces to treat spinal deformities. And if a brace is used, it’s not clear whether a rigid brace or a soft one is more effective. One thing is certain: No brace can help if the patient doesn’t wear it, and compliance—that is, the patient’s willingness to comply with doctor’s orders to wear the brace—can be lacking.5
Extreme curvature (over 50 degrees), neurological issues, or severe pain may indicate the need for surgical intervention. The surgery typically involves discectomy and fusion to relieve pain, to straighten and stabilize the spine, and keep the deformity from progressing.6
Advances in radiographic (x-ray) technology allow doctors to see how the spine looks under weight-bearing conditions (sometimes called standing x-rays, upright radiographs, or stereoradiographs). In addition, surgical planning software has made it easier and faster for doctors to set targets for postsurgical alignment and simulate the steps necessary to achieve these goals. If a simulation falls short, the surgeon can make adjustments and manipulate the electronic model until he or she has developed a solid operative plan.
Traditional (open) surgery for adult spinal deformity poses a risk of significant blood loss and serious complications. Keyhole surgery, however, particularly in the hands of an experienced surgeon, minimizes blood loss, reduces time under anesthesia, lowers the risk of infection, shortens recovery time, and reduces the rate of complications.9 Studies show that patients who receive operative treatment for spinal deformity generally have better outcomes than those who follow a nonsurgical course of treatment.10
- Have a relatively flexible spinal curvature
- Have minimal or no osteoporosis
- Have no serious spondylolisthesis
- Have no serious comorbidities, such as hypertension, COPD, or a clotting disorder
Nevertheless, there are few absolute rules in determining suitability. Many patients in poor health who cannot undergo traditional surgery are surprisingly good candidates for keyhole surgery. Your surgeon will consider many variables in deciding which approach is best for you. Be sure to talk over your options with your provider, take notes, and speak up if there’s anything you don’t understand.