Osteoarthritis

What is it?

Osteoarthritis (OA), or degenerative joint disease, is the most common form of arthritis. It most often affects middle-aged and older people, involving the neck, lower back, knees, hips and fingers. Nearly 70 percent of people over the age of 70 have x-ray evidence of the disease, but only half of these people ever develop symptoms. It may also occur in joints that have suffered previous injury, been subjected to prolonged heavy use, or damaged by prior infection or inflammatory arthritis. Patients with OA experience pain and loss of function.

What causes it?

OA results from degeneration of the joint cartilage. The causes of cartilage loss are multiple. Some kinds of OA are known to be hereditary, including the common form that causes enlargement of the knuckles. Current research focuses on this genetic abnormality as well as new methods studying cells, chemistry and function of cartilage. These efforts are creating rapid progress in our understanding of OA. In most people, cartilage breakdown is due to both mechanical ("wear and tear") effects and biochemical effects.

Who gets it?

  • OA affects more than 21 million Americans.
  • OA is the most common type of arthritis and a leading cause of disability in the U.S.
  • Virtually everyone over the age of 75 is affected in at least one joint.
  • Women are generally affected at a younger age than men. Diagnosis OA is suspected when pain develops in the commonly involved joints. It may be confirmed by a physical examination, x-rays and by ruling out other types of arthritis. Since it is so common, it may be present simultaneously with other types of arthritis.

What are the symptoms?

Stiffness is the most common symptom of osteoarthritis. The pain is localized, that is, felt only in the joints affected. The pain varies from person to person. For some, the discomfort is an occasional twinge, while others experience constant pain. Some people feel pain only when they move, whereas others also experience it while resting.

The pain is usually worst at the end of the day, because you have been using the joints for hours and they have been wearing on one another. However, pain may also intensify when the joints have been under-used; you may become very stiff if you remain still for a long period. In severe cases, the muscle around the affected joints may weaken and affect coordination. A few people feel constant, nagging pain, which seriously impedes their movement.

Osteoarthritis of the hands is usually heralded by swelling and redness. These symptoms tend to disappear as the disease progresses. The fingers are prone to developing bony growths, with finger joints becoming knobby with bony spurs (called Heberden’s nodes) appearing in the joints nearest the nails. The most common complaint is stiffness in the fingers and thumb.

The spine is the next main area. With the loss of cartilage, spurs can grow over the openings through which nerves emerge from the spinal cord to innervate different parts of the body. These bony growths appear mainly in the neck area or lower back. There is also wearing of the discs between the vertebrae, which can put pressure on nerves and possibly cause extreme pain. You may also feel what is known as “referred” pain, which is felt down the arm or leg, as a result of nerve irritation. The hip and knee joints are commonly afflicted areas because they support most of the weight of our bodies and are subject to a great deal of wear and tear over the years. Osteoarthritis in the hip can be felt in the groin or the front of the thigh, right down to the knee. Pain varies from spasmodic to constant. In the knees, the condition may strike the inner or outer part of the joint, forcing the knees to bow inwards or outwards and making the legs unstable. In severe cases, walking may become painful or even impossible.

How is it treated?

Therapy for OA includes both medication and other treatments that help to relieve pain and improve joint function.

Drug therapy should begin with simple pain relievers (Paracetamol) and progress to nonsteroidal anti-inflammatory drugs (NSAIDs eg Voltaren, Synflex) or Tramadol. The NSAID class of drugs should be avoided in patients with gastric or renal problems. A new group of NSAIDs, called coxibs (eg Celebrex, Arcoxia), have been shown to provide efficacious pain relief with far fewer gastric complications.

Apart from symptom relief, there is growing evidence suggesting that some dietary supplements (Glucosamine, Chondroitin) may have a beneficial effect in relieving pain, improving function and even in retarding the rate of cartilage degeneration. Certain medications like Doxycycline and Hydroxychloroquine may also play similar roles in modifying the course of the disease.

Corticosteroid injections into swollen and painful joints, when used judiciously (not more than 4 times a year) and under strict aseptic conditions, provide excellent albeit temporary relief. Recently, several thick liquids (eg Arthrum, Synvisc) that resemble normal joint fluid have been approved for use by repeated injection in the knee joints, giving pain relief and improved function of up to 1 year. Other therapies include patient education, occupational and physical therapy to restore joint movement and increase strength and aerobic capacity, reduction of weight on painful joints and application of heat and cold to relieve pain.

Joint surgery to repair or replace seriously damaged joints may be required to end pain and restore functional mobility.

For More Information

If you want more information on this or any other form of arthritis, visit the Arthritis Foundation web site at www.arthritis.org


Musings

Avascular Necrosis of Hip

Pre-Op DMARD Use

Hip & Knee Surgery

Predicting OA Progression

Targeted OA Treatments

Orthobiologics for Knee OA

Risk Factors for Knee OA

Running & Knee OA

Knee OA: Repair, Regenerate

Knee OA: Physical Therapy

Knee OA: Pain Management