Physical Medicine and Rehabilitation

Osteoporosis and Spinal Fractures

Anatomy

The spinal column is made up of small bones (vertebrae) stacked on top of one another, creating the natural curves of the back. Between the vertebrae are flat, round, rubbery pads (intervertebral disks) that act as shock absorbers and allow the back to flex or bend. Muscles and ligaments connecting the vertebrae allow motion while providing support and stability for the spine and upper body. Each vertebra has an opening (foramen) in the center and these line up to form the spinal canal. Protected by the vertebrae, the spinal cord and other nerve roots travel through the spinal canal. Nerves branch out from the spinal column through vertebral openings, carrying messages between the brain and muscles. Facet joints align at the back of the spinal column, linking the vertebrae together and allowing for rotation and movement. Like all joints, cartilage covers the surface where facet joints meet.

The spine contains three segments: lumbar, thoracic and cervical. The lumbar spine consists of five vertebrae located in the lower back; lumbar vertebrae are larger because they carry more of the body's weight. The thoracic spine consists of 12 vertebrae and begins at the upper chest, extending to the middle back and connecting to the rib cage. The cervical spine includes the neck and consists of seven small vertebrae, beginning at the base of the skull and ending at the upper chest. Disks in the lumbar spine are composed of a thick outer ring of cartilage (annulus) and an inner gel-like substance (nucleus). In the cervical spine, disks are similar but smaller in size.

Description

Osteoporosis is a disease of progressive bone loss that can develop unnoticed over many years, without producing symptoms or discomfort until a fracture occurs. As osteoporosis progresses, the vertebrae weaken and narrow, often causing a loss of height and a severely rounded upper back (dowager's hump), or a "bent forward" appearance to the spine. When too much pressure is placed on a vertebra weakened by osteoporosis, the patient may suffer a vertebral compression fracture. Fractures caused by osteoporosis often occur in the spine. These vertebral compression fractures occur in nearly 700,00 patients each year and are almost twice as common as other fractures typically linked to osteoporosis, such as broken hips and wrists.

Cause

Vertebrae weakened by osteoporosis are at high risk for fracture. Patients with the disease can suffer a vertebral compression fracture as a result of a fall, or while doing everyday things, such as reaching, twisting, coughing or sneezing. Vertebral compression fractures are not always a result of osteoporosis. However, when osteoporosis is involved, these fractures are often the first sign that the disease has weakened the patient's skeleton.

The exact medical causes of osteoporosis have not yet been determined, however, many factors that can lead to the disease have been identified. Increased risk for osteoporosis has been associated with: aging, heredity (small, slender build; fair skin; Asian or Caucasian ethnicity; family history of fractures), poor nutrition, low-calcium diet, low body weight, sedentary lifestyle, tobacco use, excessive alcohol consumption, certain medications (including steroids), and other illnesses (including some thyroid problems).

Symptoms

A vertebral compression fracture causes back pain, typically near the vicinity of the break. Vertebral compression fractures most commonly occur near the waistline, as well as slightly above (mid-chest) or below (lower back). The pain becomes more intense with standing or sitting for a period of time, and is frequently relieved by rest or lying down. Although the pain may move to other areas of the body, such as the abdomen or down the legs, this is uncommon.

Diagnosis

After reviewing your medical history and discussing your symptoms, your physician will perform a physical examination, checking your posture and the alignment of your spine, and pressing on certain areas of your back to determine if the source of your pain is from an injury to muscle or bone. Your physician will also check for injury to spinal nerve roots by conducting a neurologic exam that includes evaluation of your reflexes and muscle strength. To fully assess your condition and confirm your diagnosis, additional imaging studies may be required, such as X-rays, magnetic resonance images (MRI), computed tomography (CT), bone scan, and bone density testing.

When you have a vertebral compression fracture, it is important to assess whether you also have osteoporosis, and if so, how severe the condition is. X-rays will often show thinning of the bone throughout the spine (osteopenia), which is a forerunner to osteoporosis and causes bone to become much more fragile. A bone mineral density scan (DEXA) can determine the extent of your bone loss and help your physician estimate your risk for additional fractures, as well as determine appropriate medications to treat any bone density loss.

Nonsurgical Treatment

Most patients who suffer a vertebral compression fracture improve within 6 to 8 weeks without specific treatment to repair the fracture. Simple measures, such as a short period of rest and limited use of pain medications, are often all that is prescribed. Certain patients must wear a brace that restricts movement, allowing the fracture to heal. If you have also been diagnosed with osteoporosis, you are at increased risk for additional vertebral compression fractures, as well as other fractures in other areas, such as hip and wrist. Your doctor will address treatments for bone density loss during this time.

Surgery

For severe pain that does not respond to initial treatment measures, vertebral augmentation surgery may be considered. The best candidates for these procedures are patients who suffer severe pain due to a recent vertebral compression fracture. As with all surgeries, there are specific advantages, disadvantages and risks associated with each approach and none are ideal for every patient. Discuss these surgical treatments with your physician to find out if either is appropriate for the type of vertebral fracture you have, and if there is a minimally invasive option available for you. If surgery is recommended, talk to your surgeon about what to expect regarding your recovery and final outcome.

• Kyphoplasty—During surgery, a small device called a balloon tamp is inserted into the fractured vertebra. The balloon tamp is inflated from within the vertebra, restoring the height and shape of the vertebral body. When the balloon tamp is removed, the remaining cavity is filled with special bone cement that strengthens the vertebra. Kyphoplasty can be performed using general anesthesia (puts you to sleep) or with a local anesthesia (numbs your body around the fracture). The surgeon accesses the spine from the back while the patient lies face down on the operating table. After surgery, patients can return to normal daily activities as soon as possible, with no restrictions.
• Vertebroplasty—This technique similar to kyphoplasty, but the bone cement is injected directly into the narrowed vertebra, without using a balloon tamp. Vertebroplasty can be performed using general anesthesia (puts you to sleep) or with a local anesthesia (numbs your body around the fracture). The surgeon accesses the spine from the back while the patient lies face down on the operating table. After this surgery, patients are encouraged to return to normal daily activities as soon as possible.

Complications

As with any surgery, there are some risks, and these vary from person to person. Complications are typically minor, treatable and unlikely to affect your final outcome. For most people, surgery can provide relief of symptoms and return to function with relatively low risk of complications. Overall, elderly patients have higher rates of complications from surgery, as do patients who are overweight, diabetics, smokers, or suffering from multiple medical problems. Among the general, potential risks associated with surgery are infection, bleeding and blood clots, and reactions to anesthesia. Be sure to discuss the potential risks and benefits with your surgeon prior to surgery.