Spinal fracture treatment leads to more fractures

In elderly people with spinal fractures related to osteoporosis, a treatment procedure called kyphoplasty may actually increase the short-term risk of another fracture, reports a study in a recent issue of the journal Spine.

Dr. David Fribourg and colleagues of St. John's Health Center, Santa Monica, Calif., analyzed 38 patients undergoing kyphoplasty for fracture of one of the spinal bones (vertebrae). In the kyphoplasty procedure, a balloon is used to line up the fragments of the fracture, then an acrylic cement is injected to hold the fragments in place. The patients were mostly women, who have higher rates of the bone-wasting disease osteoporosis. The average age was 81 years.

An average of eight months after kyphoplasty, 10 of the 38 patients suffered an additional vertebral fracture. In eight of these patients, fracture occurred within the first two months after kyphoplasty, a rate of 21%. In contrast, for patients not undergoing kyphoplasty after a vertebral fracture, the estimated risk of additional fracture was five percent.

Of the total 17 fractures, 76% occurred at a neighboring spinal bone – one above or one below the original fracture. All of the fractures in neighboring vertebrae happened within the first two months after kyphoplasty.

Fractures of the spinal bones are a major complication of osteoporosis. Kyphoplasty is a relatively new, minimally invasive treatment that effectively reduces pain after vertebral fractures. In their first few years performing the procedure, Dr. Fribourg and colleagues noticed an apparent increase in subsequent fractures of neighboring vertebrae after kyphoplasty.

The new study supports this clinical impression: at least in the first two months after kyphoplasty, patients seem to be at increased risk of fracture of adjacent vertebrae. This risk may be related to the fact that the injected cement makes the treated vertebra stiffer, placing additional strain on the bone of neighboring vertebrae. After several weeks, fracture risk may decrease as the bone adapts.

SOURCE: “Incidence of Subsequent Vertebral Fracture after Kyphoplasty,” Spine 29(20):2270-2276, October 15, 2004.