Vertebral compression fractures
An estimated 10 million Americans have osteoporosis, and an additional 34 million are estimated to have low bone mass, placing them at increased risk for developing vertebral compression fracture (VCF), the most common fracture in people with osteoporosis. VCFs affect an estimated 25 percent of all postmenopausal women in the United States. Although far more common in women, VCFs are also a major health concern for older men. People who have sustained one osteoporotic vertebral compression fracture are at five times the risk of sustaining a second VCF.
VCFs occur when the bony block or vertebral body in the spine collapses, which can lead to severe pain, deformity and loss of height. These fractures more commonly occur in the thoracic spine (the middle portion of the spine), especially in the lower part. While osteoporosis is the most common cause, fractures may also be caused by trauma or metastatic tumors.
In people with severe osteoporosis, a VCF may be caused by simple daily activities, such as stepping out of the shower, sneezing vigorously or lifting a light object. In people with moderate osteoporosis, it usually takes increased force or trauma, such as falling down or attempting to lift a heavy object to cause a VCF. People with healthy spines most commonly suffer a VCF through severe trauma, such as a car accident, sports injury or a hard fall.
Metastatic tumors may be the cause in patients younger than 55 with no history of trauma or only minimal trauma. The bones of the spine are a common place for many types of cancers to spread. The cancer may cause destruction of part of the vertebra, weakening the bone until it collapses.
- Sudden onset of back pain
- An increase of pain intensity while standing or walking
- A decrease in pain intensity while lying on the back
- Limited spinal mobility
- Eventual height loss
- Eventual deformity and disability
Complications related to VCFs include:
- Segmental Instability
- Neurological Complications
When a fracture leads to a vertebral body collapse of more than 50 percent, there is a risk of segmental instability. The spinal segments work together to enable weight bearing, movement and support of the entire spine. When one segment deteriorates or collapses to the point of instability, it can produce pain and impair daily activities. The instability ultimately results in quicker degeneration of the spine in the affected area.
Kyphosis is a common disorder in older women who have osteoporosis and frequent VCFs. The front of the vertebrae will collapse and "wedge" due to the lack of normal vertebral space. Kyphosis leads to a more rounded thoracic spine. This deformity is sometimes referred to as hunchback or dowager’s hump.
Severe kyphosis may cause extreme and debilitating pain. The deformity may eventually compress the heart, lungs and intestines, which in turn can lead to fatigue, shortness of breath and loss of appetite.
If the fracture causes part of the vertebral body to place pressure on the spinal cord, the nerves and spinal cord can be affected. The normal space between the spinal cord and beginning of the spinal canal can be reduced if pieces of the broken vertebral body push into the spinal canal.
The narrowing of the spinal canal due to a VCF can lead to immediate injury to the spinal nerves, or can cause problems later from irritation of the nerves. The lack of space can also lower the supply of blood and oxygen to the spinal cord. This can lead to numbness and pain in the affected nerves. The nerves may lose some of their mobility when the space around them decreases, which can lead to nerve irritation and inflammation.
While a diagnosis can usually be made through history and a physical examination, diagnostic imaging can confirm a vertebral compression fracture.
- CT scan
- Dual-energy x-ray absorptiometry (DEXA) or bone densitometry
Traditionally, people with severe pain from VCFs have been treated with bed rest, medications, bracing or invasive spinal surgery, often with limited effectiveness. Pain secondary to acute vertebral fracture appears to be caused in part by vertebral instability (nonunion or slow-forming union) at the fracture site. VCF-related pain that is allowed to heal naturally can last as long as three months. However, the pain usually decreases significantly in a matter of days or weeks.
Your doctor may order bed rest for a short period of time, followed by a limitation on some activities. However, prolonged inactivity should be avoided.
Your doctor may also recommend the over-the-counter pain medications acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs), which are often effective in relieving pain. Narcotic pain medications and muscle relaxants may be prescribed, but only for short periods of time, due to the risk of addiction.
Back bracing can provide external support to limit the motion of fractured vertebrae, similar to the support a cast provides on a leg fracture. The rigid style of back brace limits spine-related motion greatly, which may help reduce pain.
While immediate treatment is essential to alleviating the pain and risks of the fracture, prevention of subsequent fractures is very important. Your doctor may prescribe bone-strengthening drugs known as bisphosphonates (Actonel, Boniva, and Fosamax) to help stabilize or restore bone loss.
When conservative treatment options prove ineffective, two minimally invasive procedures, called vertebroplasty and kyphoplasty may be treatment options for some patients. Recent advances in spinal procedures have reduced the need for invasive surgery in many cases.
Vertebroplasty and Kyphoplasty
Vertebroplasty for the treatment of VCFs was introduced in the United States in the early 1990s. The procedure is usually done on an outpatient basis, although some patients stay in the hospital overnight. Vertebroplasty takes from one to two hours to perform, depending on the number of vertebrae being treated.
The procedure may be performed with a local anesthetic and intravenous sedation or general anesthesia. Using x-ray guidance, a small needle containing specially formulated acrylic bone cement is injected into the collapsed vertebra. The cement hardens within minutes, strengthening and stabilizing the fractured vertebra. Most experts believe that pain relief is achieved through mechanical support and stability provided by the bone cement.
A newer procedure, called kyphoplasty, involves an added procedure performed before the cement is injected into the vertebra. First, two small incisions are made and a probe is placed into the vertebral space where the fracture is located. The bone is drilled and one balloon (called a bone tamp) is inserted on each side. The two balloons are inflated with contrast medium, and are visualized using image guidance x-rays, until they expand to the desired height. The balloons are removed, and the spaces created by the balloons are filled with the cement. Kyphoplasty has the added benefit of restoring height to the spine.
Complication rates for vertebroplasty and kyphoplasty have been estimated at less than 2 percent for osteoporotic VCFs and up to 10 percent for malignant tumor-related VCFs. The benefits of surgery should always be weighed carefully against its risks. Although a large percentage of patients report significant pain relief after these two procedures, there is no guarantee that surgery will help every individual.
Source: American Association of Neurological Surgeons