Risks for Osteoporosis in Spinal Rod Surgery

The number of spinal rod surgeries (also called spinal fusion and spinal instrumentation) more than doubled during the 1990s, according to the September 2007 issue of the medical journal Spine. Studies by Brook I. Martin, M.P.H., and colleagues of the Center for Cost and Outcomes Research at the University of Washington, Seattle, showed that between 1990 and 1993, approximately 9 percent of spinal surgeries were fusions. The study also showed between 1997 and 2000, the percentage increased to 19 percent. Patients with osteoporosis often suffer from compression fractures in their vertebrae that cause severe pain and loss of mobility. Conservative treatment through medication alone might not be effective, and spinal fusion surgery might be recommended. While these surgeries have become commonplace, they are not without risk and warrant careful consideration.

Condition

• Osteoporosis (which literally means 'porous bones') is a disease that causes excessive bone density loss. This results in bones becoming brittle and vulnerable to fractures. When osteoporosis affects the spine, weakened vertebrae can develop stress fractures and even collapse.

Goal

• The goal of a spinal rod surgery procedure is to stabilize the spine by immobilizing one or more affected vertebrae and repairing the fracture by fusing them with a bone graft. Bone cells (osteoprogenitor cells), usually taken from the pelvis, are grafted onto the fractured vertebrae where they will develop into mature cells and grow into bone, fusing the targeted area. To provide support and stability while the fusion grows and takes hold, a rod is inserted and attached to other vertebrae with screws, says Medical News Today.

Effectiveness

• Bone affected by osteoporosis is difficult to graft and may not heal well. The success of the bone graft depends upon growing new bone, and this is hampered by the osteoporosis. In addition, the screws that hold the spinal rod in place must be anchored to bone that, due to osteoporosis, is weakened. Even if the osteoporosis is not advanced at the time of the surgery, if the vertebrae become brittle or fragile with the advancement of the disease, the screws could become destabilized, causing severe pain and requiring another operation. The study published in the September 2007 issue of Spine reported that from 1997 to 2000, 14 percent of the patients who had this surgery required a second operation within four years.

Risks

• If the osteoporosis is not advanced, surgery may supply needed pain relief in the short term and the osteoporosis, while not curable, can be successfully treated with medications to arrest its progression. However, this procedure is major surgery and as such carries with it the risks of infection, nerve damage and even paralysis, says the Surgery Encyclopedia.

Other Options

• A recently developed procedure called kyphoplasty is especially promising for persons with osteoporosis. Two ½-inch incisions are made on either side of the affected vertebrae and, guided by X-ray equipment, the surgeon inserts a balloon-like tool that slowly expands the fractured vertebrae into normal position. Bone cement is injected into the vertebrae, immediately repairing the fracture. Complications from this procedure are rare and the success rate is 90 percent, says the Sonoran Spine Center. Although promising, this procedure is not appropriate for everyone.