Q: Tell me about balloon kyphoplasty to treat a spinal compression fracture. I read about this on-line but it sounds too good to be true. What's the downside?

A: Vertebral compression fracture refers to a mini-collapse of a vertebra in the spine. Tiny fracture lines in the bone (usually the front half of the vertebra) result in the bone taking on a wedge- or pie shape when viewed on X-rays from the side.

This type of fracture is most common in older adults who have osteoporosis (decreased bone mass or brittle bones). Just the weight of the body and pressure from postural changes (stooped head and shoulders) can put enough pressure (or compression, hence the name compression fracture) on the bone to cause a collapse.

The balloon kyphoplasty procedure is designed to restore height of the fractured and collapsed vertebra.

Two long needles are inserted through one or both sides of the spinal column into the fractured vertebral body. These needles guide the surgeon while drilling two holes into the vertebral body. The surgeon uses a fluoroscope (special 3-D real-time X-rays) to make sure the needles and drill holes are placed in the right spot.

The surgeon then slides a hollow tube with a deflated balloon on the end through each drill hole. Inflating the balloons restores the height of the vertebral body and corrects the kyphosis deformity. Before the procedure is complete, the surgeon injects bone cement into the hollow space formed by the balloon. The cement is injected a little bit at a time until the cavity is filled. They try to keep most of the cement in the front three-fourths of the vertebral body. This fixes the bone in its corrected size and position and supports the front part that has collapsed the most.

This procedure halts severe pain and strengthens the fractured bone. However, it also gives the advantage of improving some or all of the lost height in the vertebral body, helping prevent or correct kyphosis. It does not, however, prevent a second or subsequent fracture from occurring at the next (adjacent) level. In fact, there is some concern that the kyphoplasty might actually increase the risk of another vertebral compression fracture.

There is no doubt that the kyphoplasty procedure reduces acute pain and improves mobility because of the pain reduction. This is an important feature for the older adult who is also concerned about losing function and independence. But as you suggested, there are some potential complications with this procedure. Bleeding, cement leakage, spinal infection, rib fractures, and pulmonary embolism (blood clot to the lungs) head the list of possible problems.

When cement injected into the vertebral body leaks out, it hardens and can put pressure on the spinal cord and/or spinal nerves. Leakage into the disc space puts pressure on the vertebral bodies potentially increasing the risk of adjacent segment collapse. Studies show that about 20 per cent (one in five patients) will experience a second (recurrent) vertebral compression fracture after kyphoplasty.

Many patients consider it worth the risk in order to gain pain relief and improved quality of life and maintain their current level of activity and independence.

Reference: Christos P. Zafeiris, MSc, MD, et al. Hypovitaminosis D as a Risk Factor of Subsequent Vertebral Fractures After Kyphoplasty. In The Spine Journal. April 2012. Vol. 12. No. 4. Pp. 304-312.