What is it?
Vertebral augmentation is a minimally invasive procedure which treats pain and deformity associated with vertebral body fractures. Patients with osteoporosis, whether primary or due to an underlying cause (such as use of steroids to treat another medical condition), are at risk of bone fractures. Common fractures include hip, wrist, and back (vertebral compression). The low amount of calcium in bones of patients with osteoporosis reduces bone strength. A fracture can follow either from seemingly minor trauma, or even without apparent cause. The simple act of standing can cause a bone in the spine to collapse under the weight of the body it is holding. This usually causes a wedge-shaped compression, such as in this CT image:
Many patients with compression fractures actually do not develop significant pain, at least not enough to warrant a medical evaluation. In many other instances, however, these fractures can be very painful. The pain limits patient mobility and often requires relatively strong pain medications, which can have many serious side effects, especially in the elderly. Patients who become bedbound due to fracture-related pain are at high risk for other medical complications, such as infection, skin breakdown, and blood clots.
Other patients who develop compression fractures include those with an underlying malignancy. Certain cancers, such as multiple myeloma, are more prone to involve the bones, weakening them and ultimately causing bone collapse.
Apart from pain, vertebral compression fractures result in loss of overall body height and angulation deformity, whereby the spinal column at the point of fracture becomes abnormally bent, usually forward. This often results in significant posture changes, which can lead to more pain due muscle spasm and other adjustments.
This patient’s CT scans, done 8 months apart, show how a pre-existing fracture (black arrows), first seen in March, healed spontaneously without much progression by December. However, in the same time interval, two new fractures developed (yellow arrows) of previously normal-appearing vertebral bodies (white arrows). These new fractures led to marked change in the patient’s posture, as can be seen from the angulation of the spinal column.
Some patients with compression fractures will successfully heal, either spontaneously or with help of bracing, such as the TLSO (Total Lumbar Support Orthotic) Brace. Patients who cannot tolerate bracing may benefit from vertebral augmentation.
How is vertebral augmentation performed?
During the vertebral augmentation procedure, the patient is placed on his or her stomach. Under sedation, one or two cannulas (large needles) are directed into the broken bone under x-ray guidance. A toothpaste consistency substance, known as “cement”, is then injected under x-ray visualization into the broken vertebral body. In a few minutes, the cement hardens, fusing broken pieces of bone to each other, restoring strength to the broken vertebral body. Sometimes, a portion of the lost vertebral body height can be restored, though this is not the primary purpose of the procedure, nor is the restoration typically complete, as can be seen in the following patient with a severe single level compression fracture (white arrow) partially narrowing the spinal canal:
Treatment images show metal cannulas placed into the broken bone under x-ray fluoroscopic guidance. Temporary balloons are inflated in the vertebral body, which sometimes leads to some height restoration, as in this case. The balloons are deflated, removed, and cement injected into the cavity, with the final result shown in the rightmost image. The patient experienced immediate pain relief.
The procedure can be done on one or multiple broken bones at the same time, since many patients have more than one fracture. Normally, the patient is able to leave the hospital later on the same day.
What are the risks, benefits, and alternatives of the procedure?
The principal risks are infection, bleeding, and nerve damage. The risk of bleeding is very low in patients who are adequately monitored. Nerve damage (paralysis) is extremely rare though, of course, highly concerning. The risk of infection is small; however utmost precautions are taken to minimize it. The benefits include pain control, which can be achieved in the vast majority of patients with acutely painful fractures, and concomitant return to mobilization and daily activities, which reduces all manner of immobility-related complications. Alternatives include bracing (TLSO brace) or open surgery with instrumentation. Although the latter alternative is almost never willingly chosen, some patients with vertebral fractures develop compression of the spinal cord or its nerves – which cannot be remedied by vertebral augmentation and requires emergency surgery in attempt to restore function.
The physicians at the Bernard and Irene Schwartz Interventional Neuroradiology Center routinely perform vertebral augmentation. The center can be contacted by calling 212-263-6008.