Chances of Second Vertebral Fracture Increase with Steroid Use

Our senior adults are at risk for vertebral compression fractures (VCFs) due to low bone density and brittle bones (osteoporosis). Other risk factors include advancing age, steroid use, tobacco use (smoking), sex (female), and thoracic kyphosis (forward curve of the mid-spine).

Treatment is important in order to reduce pain, prevent disability, and maintain independence. Kyphoplasty is one treatment option but there’s a concern about a second (or third) vertebral compression fracture (VCF) after kyphoplasty. This study explores how often additional VCFs requiring another kyphoplasty procedure occur. They also track how soon this happens.

Compression fractures are the most common type of fracture affecting the spine. A compression fracture of a spine bone (vertebra) causes the bone to collapse in height. Kyphoplasty to treat the problem involves inserting a deflated balloon into the fractured and collapsed vertebral body.

Hydraulic pressure is used to inflate the balloon. The balloon is inflated until the vertebral body height is restored to normal or until the balloon is fully inflated. The balloon is then collapsed and removed. The empty space left by the inflated balloon is quickly filled in with cement that is injected into the area.

Kyphoplasty procedures are minimally invasive — that’s one good advantage. They aren’t supposed to be a “quick fix”. They really are used to stabilize the spine and prevent further problems. But all too often, patients go on to develop another compression fracture. In most cases, the second fracture affects the adjacent vertebral body (next spine bone above or below the original compression fracture).

Can these additional fractures be prevented? Are they caused by the kyphoplasty or something else? To find out, the authors of this study followed 256 cases of vertebral compression fracture treated with kyphoplasty. They gathered all kinds of data on each patient in order to analyze it for any possible risk factors.

Besides information on the typical risk factors, they also paid attention to the use of bisphosphonates and patient outcomes. Bisphosphonates are used to prevent bone fractures. They keep bone cells from being absorbed or destroyed.

You may be taking one of these or heard about them on TV. Boniva (ibandronate sodium) and Fosamax, known to the pharmacist and doctor as alendronate are the most commonly prescribed bisphosphonates. Others include Actonel (risedronate), Aredia (pamidronate), and Zometa (zolendronate).

Do bisphosphonates help prevent future vertebral compression fractures? That’s another question the researchers raised and tried to answer. The study was done at a single medical center. Three surgeons participated. Patients who had kyphoplasty for vertebral compression fractures over a period of seven years were included.

Two-thirds were women and the remaining one-third of the patients were men. Participants were divided into two groups based on age (over or under 75 years old). Data was also analyzed from the viewpoint of smoker vs. nonsmoker, bisphosphonate user vs. nonbisphosphonate user, and steroid user vs. nonsteroid user.

About one-fourth (22 per cent) of the entire group had a second vertebral compression fracture after the first was treated with kyphoplasty. All were treated conservatively (without kyphoplasty) at first. The kyphoplasty was only done when symptoms did not improve with nonoperative care.

Second fractures were more common in the thoracic spine compared with the lumbar spine (low back). There may be some reasons for this difference. The authors suggest perhaps the smaller sized thoracic bones just can’t support the same pressure inch-for-inch that the larger lumbar vertebrae can.

The fact that many patients who suffer thoracic vertebral compression fractures tend to be in a position of kyphosis (forward curve of the spine) might be an added factor. The kyphotic position shifts the center of gravity forward. This posture can change the dynamic shift of energy and force through the spine.

Smoking and age did not seem to factor in to additional compression fractures. Bisphosphonates did not prevent future fractures (at least not in the short-run). And the single most important risk factor for second fractures was the chronic (long-term) use of steroid medications.

What are the clinical implications of this study? First, patients who have had one vertebral compression fracture (VCF) should be monitored closely. Any signs of additional fractures must be reported and checked out right away. Older patients taking steroids who have already had one fracture are already at increased risk of another fracture and should be watched closely.

Second, if the cement used to stiffen up the vertebral segment transfers load to the next segment, is there a better way to get the same results without adding pressure above or below the fractured level? This is something surgeons may want to consider for future studies.

This study raises some interesting questions. If bisphosphonates don’t prevent additional vertebral compression fractures, does the patient benefit by taking them? Based on results of other studies, it’s possible that only long-term use (three years or more) of bisphosphonates makes a difference. But it’s something that should be investigated further.

Can dual energy x-ray absorptiometry (DXA) scans predict vertebral compression fractures? DXA scan is a bone density text to see if someone has decreased bone density (osteopenia) or brittle bones (osteoporosis). And if so, what can be done to prevent them?

With 44 million Americans expected to develop vertebral compression fractures in the next year, the answers to these questions could help prevent fractures, save lives, and reduce medical costs.

Reference: Robert L. Tatsumi, MD, et al. Predictors and Prevalence of Patients Undergoing Additional Kyphoplasty Procedures After An Iinitial Kyphoplasty Procedure. In The Spine Journal. November 2010. Vol. 10. No. 11. Pp. 979-986.