Understanding Osteoarthritis

Osteoarthritis is the most common form of arthritis affecting over 20 million Americans, and is one of the leading causes of disability and pain.

What is osteoarthritis?

Osteoarthritis (OA) is the most common joint disease affecting middle-age and older people worldwide. It is characterized by progressive damage to the joint cartilage (the slippery material at the end of the bones) and causes changes in the mechanics of the joint and also changes around the joint. These changes can lead to pain, stiffness, swelling, weakness and limitations to daily function.

OA can affect any joint but most commonly the weight-bearing joints of the knees, hips and spine. Osteoarthritis in the knee and hip areas can generate chronic pain or discomfort during standing or walking. Deterioration of disks between spine vertebrae can cause back and neck stiffness and pain.

OA also can affect the fingers and any joints with previous injury from trauma, infection or inflammation. Some patients may develop bony knobs or “nodes” that enlarge finger joints, causing pain, and stiffness and later restrict use of the fingers.

Most people with osteoarthritis describe the onset of their pain as gradual and experience joint pain during activity which can be relieved by rest. Most people also experience morning stiffness of the involved joints, often less than 30 minutes in duration. Articular gelling, or stiffness after a period of rest or inactivity, is common with osteoarthritis and resolves within several minutes of physical activity. Most osteoarthritis patients experience worsening symptoms with changes in the weather. Characteristically, their symptoms are worse in damp, cool, and rainy weather. Changes in barometric pressure may also create discomfort.

Those with later stage OA may suffer more severe pain and unstable joints, causing a sensation in the knees of giving way or “locking.” Pain at rest may mean that the disease is worsening.

What causes osteoarthritis?

OA arises from problems with the cartilage that cushions the ends of bones. This slippery material serves as the body’s “shock absorber,” providing a smooth gliding surface for joint motion that reduces friction in the joints as the body moves. When the cartilage is damaged or worn, tendons and ligaments can stretch painfully or, worse, bones can come into contact. Joint damage leads to misalignment of joint surface, which can further compound joint damage.

Phases of OA

Cartilage loses elasticity and is more easily damaged by injury, and excessive use. These changes may be influenced by age, heredity, and trauma.

As the cartilage breaks down, changes occur in the underlying bone, including bone spurs and bone cysts.

Small pieces of bone and cartilage become displaced and float loosely in the joint space.

Finally, the joint capsule lining, or synovium, becomes inflamed because of the cartilage breakdown. Along with this inflammation, inflammatory proteins called cytokines, and enzymes are produced that may further damage the cartilage. This inflammation may decrease the quality of the synovial fluid, which may reduce its protective function.

Although the cause of osteoarthritis is not known, risk factors include heredity, obesity, joint injury, repeated overuse of joints, muscle weakness, nerve injury, and age. Age, in and of itself, is not a definitive cause of OA, but can worsen the deterioration process. To help prevent OA it is important to maintain muscle strength and a healthy weight.

Who gets osteoarthritis?

OA strikes people of all ages, but is more common in older populations. Two-thirds of people over the age of 65 have X-ray evidence of OA of the knees. However, only half ever develop symptoms. Women are affected more often than men, especially with OA of the fingers and the knees.

How is osteoarthritis diagnosed?

The diagnosis of osteoarthritis can be made by clinical history and physical examination, and confirmed by plain x-rays. Additionally, routine laboratory tests are helpful in screening for associated conditions and for establishing a baseline for monitoring therapy. OA is suspected when patients have pain in the commonly involved joints. Bony enlargement is common and limitation of motion increases with arthritis severity. Malalignment of the joint, crepitus, a gravelly noise on joint motion, joint warmth, and joint swelling may also occur. Since osteoarthritis is so common, it may be present simultaneously with other types of arthritis. There are more than 100 diseases that cause arthritis and other potentially disabling disorders of the joints, muscles, and bones. Appropriate therapy requires an accurate diagnosis.

How is osteoarthritis treated?

Because of the variable nature of this serious disease, the treatment of osteoarthritis must be individualized. Selecting the best treatment requires a mutual effort by the patient and the physician. The underlying principles of managing osteoarthritis include relieving symptoms, maintaining and/or improving function, limiting physical disability, and avoiding drug toxicity. A good treatment program includes patient education, physical and/or occupational therapy, exercise, weight control, and medication.

Physical measures such as exercise, support devices and heat or cold therapies are usually effective. Some forms of alternative treatment such as spa, massage, acupuncture, and chiropractic manipulation can help relieve pain for a short duration, but usually are costly and require repeated treatments.

There are many available forms of drug therapy for the treatment of OA. Topical agents such as capsaicin cream, work by reducing Substance P, a chemical that sends pain signals to the brain. Aspirin or salicylate-based creams work by stimulating blood flow. Skin irritant creams stimulate nerve endings in the skin to cause feelings or cold or warmth, which distract from the actual pain.

Oral pain relievers such as acetaminophen or Tylenol do not reduce the inflammation or swelling sometimes associated with OA, but when used appropriately they are useful when pain is the main problem. For most people, acetaminophen is a safer alternative than nonsteroidal anti-inflammatory drugs.

Nonsteroidal anti-inflammatory drugs, or NSAIDs, help reduce joint pain, swelling and inflammation. Over the counter NSAID examples include aspirin, ibuprofen, naproxen sodium, and ketoprofen. Whether using a prescription or over the counter nonsteroidal anti-inflammatory drug, these medicines are not without significant potential side effects. To ensure safety and avoid drug interaction, consult your doctor before using any of these agents, especially in combination with any prescribed drugs.

For more serious pain, stronger medications such as narcotics may be considered occasionally for moderate to severe pain. Long-term use can cause dependency and tolerance which can cause a need to increase the dose over time to maintain benefit.

Joint injections with synthetic corticosteroids are related to cortisone, a natural body hormone, and are commonly used in the treatment of OA. Corticosteroid injections in the same joint are usually limited to three to four injections a year.

Hyaluronic acid therapy, a form of lubricant found naturally in joint fluid and in cartilage, have proven effective for some patients. In people with knee OA, inflammation causes hyaluronan to break down and become defective. Hyaluronan injections are given directly into the joint once a week for 3-5 weeks depending on which product is used.

Surgical options such as arthroscopy or joint replacement are considered when the joint is seriously damaged, or the patient is in intractable pain and experiencing significant loss of function.

Many nutritional supplements have been used for treatment of OA, but most lack good research data to support their effectiveness and safety. Recent studies have shown that patients with moderate to severe pain from knee OA might benefit from chondroitin/glucosamine sulfate supplementation. Again, to ensure safety and avoid drug interaction, consult your doctor before using any of these agents.

Living with osteoarthritis?

There is no cure for OA, but you can help manage how it impacts your lifestyle. For instance, giving proper positioning and support to the neck and back during sitting or sleeping; adjusting furniture such as raising a chair or toilet seat; and avoiding trauma and repetitive motions of the joint, especially frequent bending, are excellent starts.

Adding regular exercise to your daily activities will improve muscle strength. Exercises that increase strength of the quadriceps muscles or the thigh muscles can also help prevent knee OA. Working with a physical or occupational therapist can help you learn the best exercises and assistive devices, such as a cane, for your joints.

Weight loss in obese people can reduce pain and progression of OA, achieving and keeping an ideal weight will make a substantial difference in comfort levels.

In Conclusion

Osteoarthritis (OA) is characterized by a gradual loss of cartilage from the joints and, in some people, joint inflammation. OA can affect almost any joint, although it occurs most frequently in the hands, knees, hips, and spine. Common symptoms include pain, stiffness, and decreases in joint mobility. Changes in the appearance of affected joints can occur and may be bothersome. OA is a chronic condition that gradually worsens over time. However, treatment can often reduce the symptoms, sustain a person’s level of physical activity, and possibly slow the progression of this condition. The treatment of OA is tailored to many individual factors, including the severity of the condition, the specific joints affected by arthritis, and the effectiveness of a treatment. It is important to work with a rheumatologist to create an effective and acceptable long-term plan for living with OA.

Thank you for taking the time to learn more about Osteoarthritis. Our team of Mayo Clinic trained and Board Certified Rheumatologists at the Arthritis Center of Nebraska consider it our privilege to help people with arthritis and autoimmune diseases. We invite you to call 402-420-1212 for more information or to schedule an appointment.

Fast Facts

Osteoarthritis is caused by cartilage breakdown in one or more joints in the fingers, hips, knees, feet, and the spine in the neck and lower back.

Being overweight, age, injury and/or stress to the joints, and family history can predispose you to osteoarthritis.
Your rheumatologist can make medical and physical treatment recommendations that will increase your comfort level.
Points to Remember

OA, the most common arthritis, affects more than 21 million Americans and is a leading cause of disability.
Because it is so common, OA can also occur together with other types of arthritis.

Evaluation is needed by your doctor to confirm the diagnosis and develop an appropriate treatment plan to help relieve the pain and restore function.

At present, there is no available therapy that can reverse the damage of OA in the joint, but many studies are underway.

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About the Author

A Texan by birth, Dr. Rick Chatwell was born and raised in San Antonio. He graduated with Honors from what is now the University of the... Read more.