Vertebroplasty 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 Liquid bone cement is injected into the affected vertebrae and the needle is withdrawn.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.