Osteoarthritis

Osteoarthritis in general, is the most common type of arthritis, and affects middle-aged or older people more frequently. It can cause a breakdown of cartilage in joints and can occur in almost any joint in the body. It most commonly affects the hips, knees, hands, lower back and neck. Cartilage is a firm, rubbery material that covers the ends of bones in normal joints. It serves as a kind of ‘shock absorber” – helping to reduce friction in the joints.

When osteoarthritis affects the spine, it is known as spondylosis. Spondylosis is a degenerative disorder that can cause loss of normal spinal structure and function. Although aging is the primary cause, the location and rate of degeneration varies per person. Spondylosis can affect the cervical, thoracic, and/or lumbar regions of the spine, with involvement of the intervertebral discs and facet joints. This can lead to disc degeneration, bone spurs, pinched nerves, and an enlargement or overgrowth of bone that narrows the central and nerve root canals, causing impaired function and pain.

When spondylosis affects the lumbar spine, usually several vertebrae are involved. Because the lumbar spine carries most of the body's weight, activity or periods of inactivity can both trigger symptoms. Specific movements, sitting for prolonged periods of time, and lifting and bending may all increase pain.

A patient may develop spinal stenosis when spondylosis worsens. Spinal stenosis is a narrowing of spaces in the spine which results in pressure on the spinal cord and/or nerve roots. The narrowing can affect a small or large area of the spine. Pressure on the upper part of the spinal cord may produce pain or numbness in the shoulders and arms. Pressure on the lower part of the spinal cord or on nerve roots branching out from that area may cause pain or numbness in the legs.

Degenerative spondylolisthesis (slippage of one vertebra over another) is caused by osteoarthritis of the facet joints. Most commonly, it involves the L4 slipping over the L5 vertebra. It most frequently affects people age 50 and older. Symptoms may include pain in the low back, thighs, and/or legs, muscle spasms, weakness, and/or tight hamstring muscles.

Incidence and Prevalence

• Close to 21 million people in the United States have osteoarthritis.
• By 2030, 20 percent of Americans, or about 70 million people age 65 and older will be at risk for osteoarthritis.
• Fifty percent of people age 65 and older exhibit evidence of osteoarthritis in at least one joint on x-ray studies.
• Osteoarthristis is more prevalent in men age 45 and younger, but more prevalent in women age 50 and older.

Symptoms

• Pain and stiffness in the neck or low back
• Pain that radiates into the shoulder or down the arm
• Weakness or numbness in one or both arms
• Pain or morning stiffness that lasts for about 30 minutes due to inactivity
• Pain that worsens throughout the day due to activity
• Limitation of motion

Causes

While the cause of osteoarthritis is unknown, the following factors may increase the risk of developing the condition:

• Age
• Heredity
• Being overweight
• Joint injury
• Nerve injury
• Repeated overuse of specific joints
• Lack of physical activity

Diagnosis

A diagnosis can usually be made based on specific symptoms, a thorough physical examination, and x-ray results. On occasion, magnetic resonance imaging (MRI) may be ordered to determine the extent of damage in the spine. MRI can reveal damaged cartilage, loss of joint space, or bone spurs.

Nonsurgical treatment

• Anti-inflammatory medications to reduce swelling and pain, and analgesics to relieve pain. Most pain can be treated with nonprescription medications, but if pain is severe or persistent, your doctor may recommend prescription medications.
• Epidural injections of cortisone may be prescribed to help reduce swelling. This treatment is not recommended repeatedly and usually provides only temporary pain relief.
• Physical therapy and/or prescribed exercises may help stabilize your spine, build your endurance, and increase your flexibility. Therapy may help you resume your normal lifestyle and activities. Yoga may be effective for some people in helping to manage symptoms.
• Maintaining a proper weight is crucial to effective management of osteoarthritis. Being overweight is a risk factor for osteoarthritis.

Surgical treatment for spondylosis is uncommon, unless the condition has lead to severe spinal stenosis. Surgery may be recommended if conservative treatment options, such as physical therapy and medications do not reduce or end the pain altogether, and the pain greatly impairs the person’s daily functions. As with any surgery, a patient’s age, overall health, and other issues are taken into consideration when surgery is considered.

Copyright, the American Association of Neurological Surgeons, June 2006.