Also known as degenerative joint disease (DJD), osteoarthritis (OA) typically affects the joints in the spine, hip, knees, feet, and hand. The condition is also considered the most common form of arthritis. OA is a chronic disease of the bone and the joint cartilage secondary to “wear and tear.”
When the cartilage in the joint deteriorates, osteoarthritis occurs. The process is usually gradual.
- In its early stages, the cartilage’s surface becomes swollen and inflamed. The joint also loses proteoglycan molecules alongside other tissues. It will also begin to lose water. Pits and fissures will appear in the cartilage.
- As the disease progresses, the cartilage will start to get hard. It then becomes more prone to damage from injury and repetitive use.
- Over time, a large amount of the cartilage will be destroyed, leaving the bone ends unprotected.
When abnormalities in the bone around arthritis joints develop, the process can get more complicated. As the body attempts to repair the cartilage damage, other problems can occur:
- Clusters of fluid-filled cysts or damaged cells can form near the fissures or around the bony areas in the cartilage.
- Fluid pockets may also form within the bone marrow and may result in swelling.
- Bone cells may also respond to the damage by growing, forming, and multiplying misshapen and dense plates around the areas exposed.
- At the joint margins, the bone may produce outcroppings where chondrocytes (cartilage cells) will grow and multiply abnormally.
The exact causes of the condition are not known. However, scientists believe it develops from a combination of factors, including:
With increasing age, the body’s ability to repair the cartilage also deteriorates. While OA typically accompanies ageing, osteoarthritic cartilage has been found out to be chemically different from normal cartilage of the same age. As chondrocytes age, they also lose their ability to produce more cartilage and make repairs. This process is believed to play a crucial role in the development as well as the progression of the condition.
Joint damage from recurrent stress or injuries is considered one of the typical starting points in the OA disease process. Osteoarthritis can sometimes develop years after a single traumatic injury to or near the joint. Patients with hip injuries are three times more likely to develop OA in the injured hip while those with knee injuries are up to five times more likely to develop the condition in the injured knee. Proper treatment of injuries (i.e. surgical repair of ligament tears) together with a strong rehabilitation approach may help prevent the condition from developing. Eccentric overload like bowed legs or “knock-knees” may also lead to accelerated wear-and-tear on the side of the bend.
OA tends to run in families. Genetic factors are believed to be involved in at least half of OA cases in the hips and hands. To date, genes that are known to contribute to the inherited risk are still under investigation.
The overreaction of the immune system to an injury or infection is called an inflammatory response. This response can also cause specific immune factors (cytokines) to gather in the area injured and cause damage and inflammation to the cells and body tissues. Inflammation is believed to play a minor role in the early stages of the disease but it is considered more of a result as opposed to a cause. However, inflammation has been known to contribute to the condition’s progression.
Treatment for OA
Osteoarthritis has no cure. However, there are treatment options available that can help relieve the symptoms and improve the patient’s quality of life significantly. The primary goals of OA treatment include enhancing joint function and minimizing pain. Treatment interventions for osteoarthritis include:
A long period of inactivity may cause the arthritic joint to stiffen. It can also cause the adjoining muscles to waste away (atrophy). A moderate exercise program that includes strength training and low-impact aerobics is considered beneficial for patients with OA. While exercise won’t be able to slow down the progression of the disease, it can help:
- Increase flexibility and reduce stiffness. It may also help enhance the elasticity and strength of the knee cartilage.
- Promote weight loss.
- Improve balance and endurance.
- Reduce stress and promote feelings of well-being.
Three types of exercises are recommended for people with osteoarthritis:
- Resistance or strengthening exercises
- Range of motion (ROM) exercises
- Endurance or aerobic exercises
Exercise is known to be especially beneficial for patients with mild to moderate OA in the knee or hips. However, all weight-bearing exercises must be of the “low-impact” type. Many patients who participate in resistance and aerobic programs report less pain and disability compared to their inactive counterparts. They are also better able to perform routine tasks and remain more independent. However, older patients and those with other medical problems are required to check with their doctors first before starting any exercise program.
Physical and Occupational Therapy
Apart from exercise, treatment of muscles and joints by a physical therapist is considered beneficial. An occupational therapist can also teach patients ways of performing daily tasks easier and without putting any stress on the joints. This is especially applicable to arthritis affecting the hands. Physical and occupational therapists can also recommend changes in the home or workplace so repetitive or damaging motions are avoided.
Several devices are available that can help protect and support the joints. These devices include shoe inserts, splints, and braces. A device called offloading brace is also available for those with knee osteoarthritis caused by bowed legs or knock-knees.
Nonsteroidal Anti-Inflammatory Drugs (NSAIDs)
Nonsteroidal anti-inflammatory drugs (NSAIDs) work by blocking prostaglandins. Prostaglandins are the substances that dilate the blood vessels and cause pain and inflammation.
There are several NSAIDs currently available, including:
- Over-the-counter (OTC) NSAIDs – ibuprofen (Motrin Advil), ketoprofen (Orudis KT, Actron), and naproxen (Naprosyn, Aleve).
- Prescription NSAIDs – tolmetin (Tolectin), diclofenac (Cataflam, Voltaren, Arthrotec), ketoprofen (Orudis), indomethacin (Indocin), and meloxicam (Mobic).
- Topical NSAIDs (OTC or prescription creams, gels, or patches) – trolamine salicylate (Myoflex, Aspercreme).
When pain is severe and pain medications have proven ineffective, doctors may recommend corticosteroid injections. The injections can be given every 3-4 months. However, corticosteroid shots are often only beneficial when there is joint inflammation. It often provides only short-term relief and is rarely recommended for chronic osteoarthritis.
Diverse surgical procedures are available as last resort to relieving pain and increasing function in patients with OA. While certain surgical procedures have been known to help alleviate the pain, in some cases, joint replacement surgery might still be recommended at the end-stage of disease.
Arthroscopy and Debridement
Arthroscopy is carried out to clean out cartilage and bone fragments that may have caused the inflammation and pain. It is also used to remove loose bodies which can cause locking. The procedure is believed to benefit those patients with mild to moderate OA and those with evidence of cartilage and bone fragments in the joints. A tight lateral ligament of the patella (knee cap) can also be released so as to relieve frictional forces.
Arthroplasty (Joint Replacement)
When OA becomes so severe that immobility and pain make normal functioning impossible, the patient may become a candidate for artificial (prosthetic) joint implant using a procedure known as replacement arthroplasty. Hip replacement is considered the most successful and established procedure, followed by knee replacement. Other joint surgeries (elbows, wrists, fingers, and shoulders) are less common, while some arthritic joints (in the spine) have not been treated in the same manner. When two joints (for instance, both knees) needs replacement, doing the operations sequentially rather than at the same time is recommended to merit fewer complications.