Compression Fractures of the Spine
In a compression fracture of the spine, the drum-shaped part (body) of one or more back bones (vertebrae) collapses into itself and becomes squashed (compressed) into a wedge shape.
Most compression fractures result from slight or no force in older people with osteoporosis.
In most people, compression fractures due to osteoporosis do not cause any symptoms, but when pain occurs, walking, standing, or sitting for a long time worsens the pain.
Doctors diagnose spinal compression fractures with x-rays.
Treatment can include braces, comfort measures, and sometimes injection of bone cement into the fractured bone.
The spine consists of 24 back bones plus the tailbone (sacrum). The back bones bear most of the body's weight and thus are under a lot of pressure. A back bone consists of a drum-shaped part (body) in the front, a hole for the spinal cord, and several projections of bone (called processes) in the back. Disks of cartilage between each back bone help cushion and protect the bones.
In compression fractures, the body of a back bone collapses, usually because of too much pressure. These fractures usually occur in the middle or lower back. They are more common among older people, typically those with osteoporosis, which weakens the bone. Sometimes these fractures occur in people who have cancer that has spread to the spine and weakened it (called pathologic fractures). When bone has been weakened, compression fractures can result from very slight force, as may occur when people lift an object, bend forward, get out of bed, or stumble. Sometimes people do not remember any event that might have caused the fracture.
Occasionally, compression or other types of spinal fractures result from great force, as may occur in a car crash, a fall from a height, or a gunshot wound. In such cases, the spinal cord may also be injured (see Injuries of the Spinal Cord and Vertebrae), and the spine may be fractured in more than one place.
About two thirds of the people with compression fractures due to osteoporosis do not have any symptoms. They feel no pain when the fracture occurs.
Sometimes when a compression fracture occurs, it causes sudden, sharp pain in the back. Or pain may develop gradually. The pain may be mild or very severe. It may be constant and dull and may worsen when people stand, walk, bend forward, or sit for a long time. Gently tapping along the back, as doctors do during the examination, causes discomfort.
The pain typically decreases after about 4 weeks and disappears after about 12 weeks.
If several back bones fracture, people may become shorter, and the back may become rounded and bent—a condition sometimes called a dowager's hump (kyphosis). People may be unable to stand up straight. They may have difficulty bending, reaching, lifting, climbing stairs, and walking.
Rarely, the spinal cord or spinal nerve roots (which pass through the spaces between the back bones) are injured. This injury is more likely when the compression fracture results from great force, as occurs in a motor vehicle crash or a fall from a great height.
Spinal cord injuries can cause numbness and loss of sensation, weakness in the legs, and paralysis (see Figure: Where Is the Spinal Cord Damaged?). People may become unable to control urination or bowel movements (incontinent).
Spinal nerve root injuries are usually much less serious. They tend to cause pain that radiates to the leg and sometimes cause slight weakness of one leg or foot.
Doctors suspect compression fractures based on symptoms. They then do a physical examination. They gently tap along the middle of the back to see if pain results. X-rays are taken to confirm the diagnosis.
Doctors may measure bone density to determine whether osteoporosis is present and, if so, how severe it is (see Tests for Musculoskeletal Disorders : Dual-Energy X-Ray Absorptiometry (DXA)).
Treatment focuses on relieving pain, enabling people to function normally, and preventing other fractures. Most compression fractures heal on their own, although slowly.
Pain relievers (analgesics), such as acetaminophen, can relieve pain. Occasionally, when the pain is severe, doctors prescribe opioid pain relievers.
If fractures occur in the lower spine, wearing a brace is sometimes recommended to relieve pain and make walking less painful. How effective bracing is unclear. Sometimes bed rest is needed for a few days. However, people are encouraged to sit up and walk for short periods and to resume normal activities as soon as possible. Doing so helps prevent loss of muscle tone and additional loss of bone density.
Physical therapists can help by teaching people how to lift correctly and teaching them exercises to strengthen muscles around the spine, but therapy may need to be delayed until the pain is controlled.
Two minimally invasive procedures can sometimes be done to help relieve pain and possibly restore height and improve appearance:
Vertebroplasty: After injecting a local anesthetic near the fractured back bone, doctors inject an acrylic bone cement into the collapsed back bone. The cement hardens in about 2 hours and stabilizes the back bone. This procedure takes about an hour for each back bone. People can go home the same day.
Kyphoplasty: In this similar procedure, a balloon is inserted into the back bone and is expanded to restore the bone to its normal shape. Then bone cement is injected.
Neither of these procedures helps prevent fractures in adjacent bones in the spine or ribs. This risk of other fractures may even increase. Other possible problems may include leakage of the cement and possibly heart or lung problems if the cement leaks into blood vessels and travels to arteries of the lungs.
If a fracture is putting pressure on the spinal cord, surgery is done to relieve the pressure within hours if possible. Prompt treatment is needed to prevent permanent injury to the spinal cord.