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Vertebroplasty and Kyphoplasty
What are spinal fractures?
Spinal fractures are the collapse or compression of the vertebrae, the bones that make up the spine, or backbone. This can be caused by a number of factors, including cancer, failure of kidney function, reduction of bone density caused by drugs taken for other problems, and other issues.
However, the overwhelming cause is the loss of bone mass due to osteoporosis. It's estimated that as many as 85 percent of the 700,000 spinal fractures experienced in the United States each year — often called compression fractures — are a result of the thinning of bone mass in the vertebrae caused by osteoporosis.
A vertebra that has experienced compression fracture frequently causes severe pain, and loses height — a moderate amount of loss at first but eventually as much as 70 percent. Results of this can be loss of overall height, deterioration of posture and development of a "humpback."
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What are vertebroplasty and kyphoplasty?
Vertebroplasty and kyphoplasty are two minimally invasive, nonsurgical medical procedures to stabilize and strengthen vertebrae that have experienced fractures with the result of intractable pain. While neither procedure cures the underlying problem that caused the fractures, both have very high success rates for ending the pain and restoring mobility and function to the patient.
Vertebroplasty uses a straw-sized hollow needle to inject medical cement into a fractured vertebra to reinforce it. Additionally, as the cement is injected, it heats up and essentially cauterizes inflamed nerve tissue to eliminate the pain it causes.
Kyphoplasty relies on the same technique — after first using an inflatable balloon inserted within the fragments of the compressed disc to elevate the endplates of the vertebral structure, restore some or all of its previous height to it and create a cavity into which cement can be injected.
Vertebroplasty, developed in France in 1984 and introduced into the United States in the mid-1990s, is viewed as a successful procedure to end pain and stabilize the vertebral fragments, but it does not affect the height of the vertebral structure itself.
A refinement developed only in the last several years, kyphoplasty represents an advantage for patients experiencing "humpback" or "hunchback" due to the effects of spinal degeneration. Restoring the height of fractured vertebrae reduces the exaggerated curvature of the spine and improves posture. It also reduces the risk of additional fracture of adjacent vertebrae by reducing pressure on them.
It's estimated that as many as 90 percent of patients who undergo vertebroplasty have substantial or complete reduction of pain, and that results are frequently experienced immediately or within a few days of treatment. It's important to note that the procedure is suitable for compressed vertebrae, but is not applicable to patients with general back problems or herniated spinal discs.
The interventional radiologists of Connecticut Surgical Group have strong expertise in the use of vertebroplasty and kyphoplasty, and have been leaders in developing techniques for their use.
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What causes spinal fractures?
Osteoporosis — the loss of bone mass — is by far the most common cause of compression fractures in the vertebrae that make up the spine, although other factors may include cancer, kidney failure, long-term use of some medications for other problems that may cause thinning of bone density, excessive alcohol consumption, trauma and other issues. Osteoporosis is estimated to be responsible for as many as 85 percent of compression fractures.
A vertebral fracture is often referred to as a compression fracture because it essentially is a collapse of the weakened vertebra. These events most often occur in the middle (or thoracic) area of the spine, or in the lower (or lumbar) area.
When one vertebra collapses, the initial effect is generally pain, caused by the way the fragments of broken bone rub against each other and inflame nerve endings that are present. When more than one vertebra collapses, any pain may be accompanied by loss of height, stooped posture or deformities such as kyphosis — commonly known as "humpback."
If the fractured bone fragments stabilize over a period of time, the pain may resolve by itself. If the pieces of bone continue to move and break up, however, pain is likely to continue.
It should be noted that while osteoporosis is a common cause of kyphosis, there are other causes as well, including congenital and neuromuscular problems, Scheuermann's disease and arthritis, infections, trauma and cancer.
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How common are osteoporosis — and compression fractures?
Osteoporosis is estimated to affect more than 30 million Americans, and it's often called a "silent disease" because many people don't realize they have it until a fracture occurs. Areas most often at risk are the hip, wrist and spine, and while 300,000 people experience hip fractures due to osteoporosis each year, some 700,000 experience vertebral fractures.
Osteoporosis affects women far more than men, principally due to the loss of bone mass women experience with menstruation and following menopause. It's estimated that during their lifetime some 50 percent of women over the age of 50 will have osteoporosis-related fractures as opposed to 10 percent of men.
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What are the risk factors for compression fracture?
Bone mass is like a trust fund into which one puts resources early on to draw out in the future. Normally, a person reaches peak mass by age 30 and then begins a natural, gradual process of bone mass loss. While a lifestyle emphasizing calcium in the diet, avoidance of factors that cause bone mass depletion and regular exercise can help offset loss of bone density, it is a lifelong challenge.
Since compression fractures result from the thinning of bone mass, risk factors for them include experiencing osteoporosis and any other issues that deplete calcium from the bones. These can include cancer, kidney failure, trauma and prolonged use of medications such as corticosteroids and anticonvulsants.
Risk factors include simply being female, especially being female and past menopause, being over age 50, being anorexic or bulimic, not ingesting enough calcium, smoking, excessive consumption of alcohol, lack of exercise and a family history of osteoporosis.
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How does vertebroplasty repair compression fractures?
Vertebroplasty is performed as a fluoroscope-guided procedure, with the patient under either general or local anesthetic. With the patient lying on his or her stomach on a special table flanked by a fluoroscopic imaging "C-arm" and a bank of video monitors to assist in real-time positioning, the interventional radiologist guides a hollow needle about the width of a drinking straw through the soft tissues of the back and into the targeted vertebral section. A small amount of medical dye is continually injected to allow visualization of the needle and its location.
Orthopedic cement called polymethylmethacrylate, or PMMA (and sometimes just methylmethacrylate), is conveyed through the needle into the vertebral structure. Used for orthopaedic joint implants for some years, PMMA has the form of a thick paste when it is introduced through the needle into the targeted boney structure. Injections are made on both the right and left sides of the vertebra. Mixed in with the PMMA is an antibiotic as a precautionary measure and a substance such as barium to permit visualization on the fluoroscope.
The PMMA hardens in about 15 minutes once in the vertebral body. In addition, the heat it generates once injected deadens inflamed nerve tissue to diminish or eliminate the pain it causes.
Following the procedure, the patient is required to remain in the recovery room lying flat for a couple of hours to give the cement time to solidify. Once up, however, he or she is often walking around without difficulty within a short period, although it can take some 48 hours for the final results to be realized. Vertebroplasty is often performed as an outpatient procedure but may entail an overnight hospital stay.
Usually, more than one vertebra can be treated in the same procedure, if necessary. The process generally takes one to two hours, depending on the number of vertebrae dealt with.
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How does kyphoplasty differ from vertebroplasty?
Like vertebroplasty, kyphoplasty involves the injection of medical cement into the collapsed vertebral structure through a hollow needle inserted under fluoroscopic guidance in order to stabilize and strengthen the targeted bone.
Beyond this, however, kyphoplasty adds a capability for dealing with structural deformity, working to restore some or all of the previous height to the collapsed vertebral structure before the cement is injected. An inflatable balloon — much like the inflatable balloon systems used in angioplasty to widen narrowed coronary arteries — is introduced into the vertebral structure through a catheter. Inflated, it pushes the endplates of the vertebra to restore size to the structure — and create a cavity within the vertebra to be filled with the cement.
The degree of vertebral height restored varies depending on the patient, the extent of damage and the volume of the balloon that can be used. In several recent studies, the average vertebral height restored was 38 to 47 percent.
Kyphoplasty offers a secondary benefit over vertebroplasty — the option to be performed with lower-pressure injections. For vertebroplasty, injection of the cement is done under high pressure, with the risk of leakage outside the vertebra and possible complications. Kyphoplasty, able to be performed with lower pressure injection and a more viscous form of cement, presents less of a risk of leakage outside the bone.
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What are the criteria for undergoing vertebroplasty or kyphoplasty?
It's important to remember that vertebroplasty and kyphoplasty are procedures related to strengthening and stabilizing vertebrae that have experienced compression fractures, and reducing or eliminating the pain specifically associated with those problems. It is not a procedure useful or appropriate for chronic back pain or herniated spinal discs.
The sooner a compression fracture can be treated with vertebroplasty and kyphoplasty after it occurs the better, and some sources suggest that treatment is optimum when it occurs less than a year after the fracture, and when back pain related to it has been present for less than a year.
Treatment is possible for older fractures, although it is likely the success in pain reduction will be reduced. It's likely that your doctor will seek to initially deal with your pain with medical management before recommending vertebroplasty or kyphoplasty.
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Will vertebroplasty or kyphoplasty cure my spine problems?
Vertebroplasty and kyphoplasty can reduce or eliminate pain and restore a capability for mobility and function, but they are not a cure for osteoporosis or any other disorder.
For that, and to reduce the likelihood of additional compression fractures, you should discuss with your doctor medications and changes in lifestyle that can reduce your risk. While osteoporosis can't be cured, there are now several medications available to deal with its bone-thinning effects.
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How safe are these procedures?
From its original development in France, vertebroplasty has been performed since the mid-1980s and has proven to be a safe, effective procedure with few complications. The risk of complications will vary with the situation of the patient — other serious medical problems may increase the risk.
And, you should keep in mind that any medical procedure carries with it very small-but-possible risks of complications such as a reaction to anesthesia, bleeding and infection.
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How should I prepare for vertebroplasty or kyphoplasty?
You should prepare for your procedure by making sure you don't take certain vitamins or aspirin, ibuprofen or other blood-thinning analgesics for at least two weeks in advance. Any herbal remedies you are using may need to be discontinued.
If you smoke, you should also stop for at least three weeks before and after your surgery, as nicotine interferes with blood supply.
You will be asked not to eat or drink after midnight of the night before your procedure.
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What happens following the procedure?
You'll be prescribed pain medications, muscle relaxants and other drugs to take as appropriate. You may be given a back brace to wear in the period following your procedure. Your incisions will be covered by bandages, which should remain in place for 24 hours. After that period, you may remove them. Be sure to keep your incisions dry for at least 24 hours.
You may be able to resume activities such as walking — and in fact walking is a beneficial activity — but you should be careful to avoid strenuous exertion such as heavy lifting or exercise for several months, and then you should increase your level of exertion gradually.
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What are other considerations related to vertebroplasty or kyphoplasty?
Most importantly, you should discuss with your doctor the risk of fracture present in other vertebrae, and to what extent you should be cautious about your physical activities. In some cases, vertebroplasty to strengthen and stabilize other vertebrae may be an option as a preventive measure in advance of a likely compression fracture.
As stated, vertebroplasty and kyphoplasty are procedures to cure pain and stabilize damaged vertebrae, but they do not cure the underlying problem that led to the loss of bone mass in the first place. Aggressive therapy may be needed to deal with these problems, whether changes in diet, exercise patterns, consumption of alcohol or use of medications that may contribute to loss of bone mass.
Therapy with new drugs such as Actonol and Fosamax that offset the bone thinning of osteoporosis, calcium supplements, vitamins and hormone treatments may be appropriate.
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For additional information
You can find additional information about vertebroplasty and kyphoplasty at web sites sponsored by government agencies, societies and healthcare institutions. It should perhaps be noted that the World Wide Web is open to many sources posting questionable information and promises, and you are encouraged to seek information from established, reputable organizations.
Likely sources include:
The Society of Interventional Radiology
www.sirweb.org
Emedicine
www.emedicine.com
Spine Universe
www.spineuniverse.com
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