Osteoporosis and Compression Fractures

Osteoporosis refers to softening of the bones, a result of a metabolic derangement. Essentially, there's an imbalance of bone production and bone resorption. This can be primary, which is most common, or secondary to corticosteroid use or other conditions. Postmenopausal women are at an increased risk for primary osteoporosis. There are a number of medications currently available to treat and prevent osteoporosis.

Increased bone fragility can lead to fractures of the spine, hip, and other bones. Osteoporotic spine fractures typically occur with axial loading (downward force), usually with a fall. However, spontaneous fractures can occur with simple, low-impact activities as well. Fractures can occur as a gradual loss of bone height, or the bone can collapse suddenly and cause more acute symptoms.

The typical osteoporotic compression fracture (OCF) or vertebral compression fracture (VCF) involves collapse of the vertebral body, one of the bones in the spinal column. The bone collapse is usually most significant in the anterior (front) part of the bone. This results in a deformity of the spine referred to as kyphosis. Kyphosis is an abnormal angulation which, if severe enough, can lead to a "hunched over" appearance.

Symptoms

Compression fractures of the spine typically cause severe back pain, which often worsens with movement. As the bone collapses, the nerve exiting the spinal canal can be compressed. This can result in pain, numbness, and tingling in the distribution of that nerve. If in the thoracic spine, it can cause shooting pain across the chest or abdomen. In the lumbar spine, it can cause pain that shoots across the groin or down the leg.

Severe fractures can result in bone projecting posteriorly into the spinal canal. Fortunately, this is less common. If significant enough, this can result in compression of the spinal cord or nerves which may cause neurologic impairment.

Treatment

Initial treatment of a pathologic compression fracture usually involves medication to treat the pain. In some cases, a brace may be prescribed to help support the spine while the fracture heals.

Ironically, bedrest or inactivity may help with the pain in the short-term, but in the long run, this can accelerate bone loss. In other words, the spine can become more fragile, leading to more fractures and disability.


When pain persists despite conservative measures, surgical intervention may be considered. There is a minimally invasive procedure that allows for percutaneous treatment of the fracture. The procedure is called a kyphoplasty, and it is performed under x-ray guidance. The fractured bone is accessed through the skin, re-expanded with a special balloon, and then filled with a cement-like substance. This can not only restore the normal anatomical configuration and reduce the kyphotic deformity, but also provide a solid re-enforcement for what was previously a weakened bone.

The procedure works well for acute and subacute pathologic compression fractures, but not for chronic (old) fractures or those that occur in normal bone (i.e. traumatic fracture in a younger patient). The discomfort from the procedure is limited, and improvement in back pain usually starts soon after the procedure. The procedure is short and minimally-invasive, so it is tolerated in fragile patients or those with complicating medical conditions.

As with any procedure, there are risks involved. It is a low-risk procedure and if you are a candidate, these will be reviewed with you in detail.

Kyphoplasty Versus Vertebroplasty

Kyphoplasty differs from vertebroplasty, which involves the direct injection of cement into a fractured bone without the use of a balloon. The balloon not only acts to restore the normal anatomical configuration, but it also creates a cavity within the bone to accommodate the cement. In theory, more cement can be placed within the fractured bone with a kyphoplasty, resulting in a more solid repair. In addition, filling the cavity created by the balloon is thought to be safer and have less risk than direct injection into the bone, which has a higher risk of cement leakage outside of the vertebral body.

Additional research is ongoing, comparing these two techniques with regard to safety, efficacy, and cost.

*illustrations courtesy of Kyphon, reprinted with permission