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Symptoms And Side Effects - Orthopedic Interventions


Orthopedic Interventions


Approximately 75% of patients with multiple myeloma experience bone pain. (Body JJ. Cancer. 97(3 suppl):859-865.) Orthopedic interventions may be required to help control pain or retain function or mobility. These may include physical therapy, splinting of bones to prevent or treat fractures, or surgical procedures (minor or major) to repair fractures.

Simply stated, patients with myeloma experience bone destruction because rapidly growing myeloma cells push aside normal bone-forming cells and produce substances that activate bone-resorbing cells. Both of these cause areas of bone weakness that can increase the risk of broken bones.

The skeletal site most often affected by myeloma is the spine. Fractures of the bones of the spine (vertebrae) are associated with bone pain in more than half of patients when they are first diagnosed. (Body JJ. Cancer. 97(3 suppl):859-865.) New vertebral fractures occur in approximately 15 to 30 percent of patients with myeloma every year. The vertebrae become so weakened that they collapse upon themselves, resulting in a compression fracture. These fractures are very painful and can lead to a stooped posture, loss of height, immobility, and further fractures. Consequently, they have a significant impact on quality of life. Compression fractures, by reducing space in the chest and abdominal cavities, can also reduce lung capacity and cause loss of appetite.

Treatment for spinal fractures includes the use of painkillers to control pain and increasing physical activity, preferably under professional supervision in the form of physical therapy. Water exercises are also very useful in the management of spinal fractures.

Symptoms of spinal fractures are sometimes treated with bed rest and braces. However, these methods may lead to further deterioration in a patient’s condition and are now being used less frequently. For example, bed rest and inactivity can lead to further weakening of the bone and decreased incorporation of new calcium into bone. Braces, although they provide significant comfort, may weaken muscles, which can also lead to further weakening of bone.

Although treatments for myeloma help control the disease, they do not correct any structural damage that may have already occurred with a fracture or stop continued worsening of the condition. Two surgical procedures - vertebroplasty and kyphoplasty - are used to treat spinal fractures due to osteoporosis (generalized bone weakening), bone metastases, or myeloma. By stabilizing the bone, these procedures help address the structural damage seen with spinal fractures, help relieve pain, and improve function and quality of life.

The sections below describe each of these procedures.

Vertebroplasty

What It Is. Vertebroplasty (ver-tee-bro-plas-tee) is a minimally invasive surgical procedure whereby the vertebrae are reinforced with a cement-like substance. The procedure is performed under general or local anesthesia. A special bone needle is injected through the skin into the affected bone while the patient is under a fluoroscope, which allows viewing of the bone during the process. Liquid bone cement is injected into the affected vertebrae and the needle is withdrawn. As the cement hardens, usually within 15 minutes, the bone is stabilized. The procedure may be repeated on the other side of the vertebrae if necessary.

Potential Side Effects. Although all surgical procedures carry some degree of risk, the risks associated with vertebroplasty are minimal in trained hands. When used in the treatment of vertebral fractures due to osteoporosis, metastasis, or myeloma, complications that have been rarely reported in the literature include increased pain, compression of a spinal nerve or the spinal cord, infection, blockage of a blood vessel in the lung, and rib fractures. (Garfin et al. Spine. 2001;26(14):1511-1515.) Further fracture of the vertebrae is also possible if excess pressure is applied. Cement leakage has been reported more commonly. In general usage, rates of cement leakage vary widely from center to center (some examples are cited below) and are dependent on technique and the type and amount of cement used.

In most cases, cement leakage usually does not cause any symptoms or problems. However, in rare cases, cement that has leaked outside the bone can put pressure on the spinal cord or a spinal nerve. This complication has been reported to occur more frequently in fractures related to metastasis or myeloma than to osteoporotic fractures. (Garfin et al. Spine. 2001;26(14):1511-1515.) In some of these cases, surgery may be required to remove the cement and relieve the pressure. Patients may be monitored by x-ray or computed tomography (CT) for up to an hour following the procedure in order to detect any cement leakage.

It is thought that the change in bone density that occurs with the introduction of cement into a vertebra may put pressure on adjacent vertebrae and increase the risk of future fractures. For this reason, patients are often monitored for new fractures following the procedure. There has also been some suggestion that cement leakage into the spinal discs (the spongy cushion between the vertebrae) following vertebroplasty may increase the risk of spinal fractures in adjacent vertebrae. (Lin et al. Am J Neuroradiol. 2004;25(2):175-180.)

Use in Myeloma. One of the first reports of use of vertebroplasty in the treatment with spinal fractures in patients with bone metastases or myeloma was reported in 1996. (Weill et al. Radiology. 1996;199:241-247.) A total of 37 patients underwent 52 vertebroplasty procedures. Seventy-three percent of the injections resulted in pain relief. Three patients experienced transient pressure on a spinal nerve due to cement leakage and one patient required surgery.

Results of another study of vertebroplasty in patients with myeloma (8) or metastatic cancer (29) demonstrated partial or complete relief after 97% of the procedures. (Cotton et al. Radiology. 1996;200:525-530.) In this study, cement leakage occurred in 29 of 40 procedures (73%), two of which required surgery.

A more recent study evaluating the use of vertebroplasty and kyphoplasty for painful vertebral fractures in patients with myeloma or other cancers showed that both procedures provided significant pain relief in 84% of patients. (Fourney et al. J Neurosurg. 2003;98(1 suppl):21-30.) Relief was immediate in most patients and appeared durable over time. A total of 97 vertebrae were treated in 56 patients at M.D. Anderson Cancer Center (TX), including 21 patients with myeloma. Asymptomatic cement leakage was seen in 6 of 65 vertebroplasty procedures (9%) and 0 of 32 kyphoplasty procedures. There were no early or delayed complications related to the procedures and no patient was worse after treatment. The authors attribute the low rates of cement leakage with both procedures in this study to the use of cement that hardens rapidly and injection of smaller volumes of cement.

Kyphoplasty

Kyphoplasty (kye-foe-plas-tee), a new technique developed for treating spinal fractures due to osteoporosis, also appears to offer benefit for patients with myeloma. It offers an additional benefit over vertebroplasty in that it helps restore the height of the compressed vertebra. The medical devices used in the procedure were developed by Kyphon Inc. and have been marketed in the United States since 1998 for use in the treatment of spinal fractures and certain other fractures.

What It Is. Like vertebroplasty, kyphoplasty is a minimally invasive procedure that is performed using local or general anesthesia. The physician makes a small incision on each side of the fractured vertebrae using x-ray guidance and creates a path into the bone using special instruments. He or she then inserts two tiny tubes, each containing a small inflatable KyphX® balloon, into the compressed vertebra (see figure). The balloons are inflated with a radiopaque dye for visualization, attempting to restore the vertebra to its original height. The balloons are removed and the cavities created by the balloons are then filled with bone cement. The bone cement usually hardens within 15 minutes. This stabilizes the bone and preserves the re-established height, relieving pain and restoring spinal alignment that may help prevent future fractures. On average, it takes about 30 to 45 minutes to treat each fracture.

[INSERT FIGURE: http://www.themmrf.org/treatments/3.07.04.php]

Figures courtesy of Kyphon Inc.

Potential Side Effects. As with vertebroplasty, the risks associated with kyphoplasty are minimal in trained hands. Although infrequent and usually clinically insignificant, cement leakage may occur. In rare cases, cement that has leaked outside the bone can put pressure on the spinal cord or a spinal nerve. In some of these cases, surgery may be required to relieve the pressure. Patients may be monitored by x-ray or computed tomography (CT) for up to an hour following the procedure in order to detect any cement leakage. Other complications that have been reported in the literature include a single case of transient fever and a blood clot in the space surrounding the spinal cord. (Garfin et al. Spine. 2001;26(14):1511-1515.)

It is thought that cement leakage may be less likely to occur during kyphoplasty than vertebroplasty because compared to vertebroplasty, the injections during kyphoplasty are performed under relatively low pressures into the preformed cavity in the bone. For this reason, a more viscous cement mixture (which may be less likely to leak) can also be used. It is thought that the change in bone density that occurs with the introduction of cement into a vertebra may put pressure on adjacent vertebrae and increase the risk of future fractures. For this reason, patients are often monitored for new fractures following the procedure.

Use in Myeloma. Data from 55 kyphoplasty procedures performed on 18 myeloma patients at the Cleveland Clinic show that that the procedure was well tolerated and resulted in rapid clinical improvement in pain and function. In addition, patients recovered about a third of the vertebral height they lost as a result of the compression fractures. No major complications were seen and asymptomatic cement leakage occurred in 2 (4%) of the procedures. (Dudeney et al. J Clin Oncol. 2002;20(9):2382-7.)

As noted above, a study evaluating the use of vertebroplasty and kyphoplasty for painful vertebral fractures in cancer patients showed that both procedures provided significant pain relief in 84% of patients. (Fourney et al. J Neurosurg. 2003;98(1 suppl):21-30.) Relief was immediate in most patients and appeared durable over time. A total of 97 vertebrae were treated in 56 patients at M.D. Anderson Cancer Center (TX), including 21 patients with myeloma. Asymptomatic cement leakage was seen in 0 of 32 kyphoplasty procedures and 6 of 65 vertebroplasty procedures. The authors attribute the low rates of cement leakage in this study to the use of cement that hardens rapidly and injection of smaller volumes of cement. There were no early or delayed complications related to the procedures and no patient was worse after treatment. Patients receiving kyphoplasty recovered an average of 42% of the vertebral height lost due to the fracture.

Although both kyphoplasty and vertebroplasty are effective treatments for spinal fractures, some clinicians prefer kyphoplasty to vertebroplasty due to the reduced incidence of cement leakage, the injection of cement under lower pressure (which may reduce the risk of further fracture of the vertebrae), and the restoration in vertebral height achieved.

Get more information about kyphoplasty and locate a physician who has been trained in the use of Kyphon devices.