Osteoarthritis: causes, symptoms, and comprehensive treatment approaches

Osteoarthritis is the most common form of arthritis mostly affecting senior citizens progressively with age though trauma-induced osteoarthritis is also observed in younger people. Osteoarthritis occurs at the joints -- elbows, shoulders, knees and the digits of the hand. A projected 20 million people are in the United States are assumed to have osteoarthritis with about 50% of people over the age of 65 suffering, as evidenced by radiology studies. Osteoarthritis affects different people differently. In some cases, it progresses more rapidly than others. Researchers have not specifically identified the cause-effect circumstances for osteoarthritis; however, besides trauma, diet, weight, and work or activity related stress on the joints (long or short-term) are said to be contributory. (Hosie and Dickson 2000; Arthritic Foundation 2002)

The consequences of osteoarthritis are varied -- physical and psychological (Wildner and Sangha 1999). Besides the financial costs and loss of wages due to disability, osteoarthritis takes its toll. Depression, anxiety, feeling of helplessness, limitations on ability to work -- feelings of inadequacy, and the loss of daily activities and responsibilities with the family have to be included in the ill-effects of osteoarthritis.

The treatment modalities then have to address, besides pain, the psychological ramifications of the disease.

The obvious treatment steps would have to include addressing the issue of constant and acute pain. On occasion surgery may be performed to reposition bones.

These can be achieved through drugs. The disease affects the joints -- therefore, joint care has to be improved through rest and a properly (custom) designed exercise regimen. Stress on joints often exacerbates the effects of the osteoarthritis; hence, an acceptable body weight has to be maintained. Patients have to be convinced to live a healthy lifestyle while also adopting an optimistic attitude.

Osteoarthritis: Cartilage and Bone

Osteoarthritis is the biochemical degeneration of the joints caused by the progressive wearing away of the cartilage in those joints. Cartilage is the slippery tissue that covers the ends of bones in a joint. The joints of the bones and the cartilage are housed in a tough membrane sac called the joint capsule. On the inner side of the joint capsule is a membrane called the synovium. This entire cavity is filled with the synovial fluid that keeps the constituents of the capsule lubricated and smooth. In addition, muscles, ligaments, and tendons keep the bones stable and allow the joint to bend and move. Ligaments are tough, cord-like tissues that connect one bone to another. Tendons are tough, fibrous cords that connect muscles to bones. (Hammerman 1989)

There are two types of osteoarthritis which pathologically manifest similarly though for different reasons. The less common type -- secondary osteoarthritis -- occurs from stress on bones of the hand, hips and knees which are typically involved in manual or weight bearing operations. The secondary kind is often seen in younger people. The reasons for occurrence of the more common type -- primary osteoarthritis -- observed in seniors are ambiguous at best. There is no apparent initiation for primary osteoarthritis.

In either of the above two cases, osteoarthritis is characterized by wearing away of the cartilage which, under normal circumstances, helps the bones in the joint glide more easily, enabling movement. As the cartilage wears away, the bones under the cartilage rub together. This absence of the lubrication causes pain, swelling, and loss of motion in the joint. Some researchers believe that over time excess stress on a healthy joint or normal stress on a previously (for known or unknown reasons) disturbed joint might cause osteoarthritis (Radin and Paul 1971). External forces accelerate the breakdown of the chondrocytes (the cells that compose the cartilage). Over time, the joint may lose its normal shape. As the cartilage wears away the amount of collagen (which maintains elasticity) also decreases. The elasticity in the joint reduces putting greater stress on the joint eventually leading to mechanical failure -- bending, lifting etc.

The underlying bone is exposed. Microscopic cracks appear on the bones; these cracks expose the inner layers of the bone to contact with the synovial fluid resulting in further bone-degeneration. Also, bone spurs -- small growths called osteophytes -- may grow on the edges of the joint. Bits of bone or cartilage can break off and float inside the joint space. (Howell 1986)

Frequency and Demographics

In the U.S., approximately 80-90% of individuals older than 65 years have evidence of primary osteoarthritis. Osteoarthritis typically develops slowly and progresses over several years. Usually, the pain slowly worsens over time, but it may stabilize in some patients. Osteoarthritis of the knee is a leading cause of disability in elderly persons. Osteoarthritis also causes millions of Americans to miss work because of back pain.

Ethnographically, primary osteoarthritis does not discriminate racially. Native Americans however, are more likely to suffer than the general population. An important example is Hong Kong where Caucasians are more likely to exhibit osteoarthritic symptoms than Chinese patients (Hoaglund, Yau et al. 1973). In persons older than 65 years, osteoarthritis is more common in whites than in blacks.

In individuals older than 55 years, the prevalence of osteoarthritis is higher among women than men especially in the distal interphalangeal joints of the fingers. Women also complain about osteoarthritis in the knee joints more frequently than men. Problems in the hips however, have a greater preponderance in men than women, as in osteoarthritis in those below the age of 45. One might attribute the secondary arthritis due to greater stress on the joints brought on by more manual-intensive labor performed by men than women.

Osteoarthritis occurrence appears to increase with patient age, in a nonlinear fashion. The prevalence of the disease increases dramatically after the age of 50 years, likely because of age-related alterations in the joint that decreases the tensile strength of the joint cartilage and diminished nutrient-supply to the cartilage. (Roberts and Baruch 1966)

Signs and Symptoms

Primary osteoarthritis is a common disorder of the elderly, and patients are often asymptomatic. Patients with symptoms usually do not notice them until after they are aged 50 years. They experience stiffness after long periods of inactivity. Deep, achy, joint pain exacerbated by extensive use is the primary symptom. Joint swelling or tenderness in one or more joints is also noticed. Also, reduced range of motion and crepitus are frequently present. After extensive wearing away of the cartilage, patients experience a crunching feeling or sound of bone rubbing against bone. Inflammatory changes are typically absent or at least not pronounced: some times the hot, red and tender feeling around a joint might be misdiagnosed or misinterpreted as osteoarthritis -- and is probably rheumatoid arthritis. Joint misalignment may be visible. Heberden nodes and/or Bouchard's nodes, which represent osteophytes in the interphalangeal joints, are characteristic in women but not men. In some cases, pain is not one of the symptoms. (Veys and Verbruggen 1999)

Diagnosis and Radiology

In X-rays and other radiology reports, a chief limitation is that the wearing away of the cartilage is not recorded. Radiology identifies problems with bones and osteoarthritis might be diagnosed after bone degeneration has already occurred -- occasionally too late to address the consequent disability.

Radiographs find different abnormalities in the stressed and non-stressed areas of the affected joint. In the highly stressed areas of the joint, radiographs can depict joint (capsule) space loss, as well as bony sclerosis and cyst formation. In the areas without high contact pressures, osteophytes can be detected. The net loss of cartilage appears as a reduction of the joint space on radiographs. In major weight-bearing joints, a greater loss of joint space occurs at those areas subjected to the greatest pressures. In the osteoarthritic knee, for example, one commonly observes the greatest loss of joint space in the medial femorotibial (between the femur and tibia) compartment although the lateral femorotibial compartment and patellofemoral compartment may also be affected.

Radiographs of the entire lower extremity are also useful for demonstrating bone misalignment. Axial projections are best for evaluating the patellofemoral (patella and femur) joint. When the patellofemoral compartment is involved, the lateral facet of the patella is more frequently affected than the medial facet, and lateral patellar subluxation (bone misalignment that cause pressure on the surround nerves) may be noted.

In the osteoarthritic hip, the superior aspect of the joint space is typically the most narrowed; axial and medial migration of the femoral head is less commonly seen. In the small joints of the hand, radiographs often show loss of joint space across the entire joint. In some cases, the interphalangeal joint may be asymmetrically affected, and radial or ulnar deviation is observed. Sclerosis is often the most prominent radiographic finding when osteoarthritis affects the facet joints of the spine.

Cyst formation is a fundamental radiographic finding in patients with osteoarthritis. Osteoarthritic cysts are also referred to as subchondral cysts and pseudocysts. Later in the disease, the subchondral bone weakens and compresses; bony collapse may be seen radiographically. This finding is commonly seen in advanced cases of osteoarthritis of the hip, in which flattening of the superior aspect of the femoral head typically occurs.

The primary radiographic finding in the less-stressed areas of the osteoarthritic joint is osteophytosis. Osteophytes are mushroom-shaped bony outgrowths that are generally seen at the margins of the joint. In the knee, sharpening of the tibial spines may be present. A bony prominence, known as the Parson bump, may develop just anterior to the tibial spines. Growth of osteophytes is one of the best indicators of disease progression. Fractured osteophytes result in loose bodies in the synovial fluid which are also observed as indicators of advanced osteoarthritis. (Jewell, Watt et al. 1998)

CT (Computer Tomography) is rarely used for the diagnosis of primary osteoarthritis, although it may be used for the diagnosis of misalignment of the patellofemoral joint or the foot and ankle joints. It may also be useful in evaluating the bones of the vertebral column. In patients who cannot tolerate MRI (Magnetic Resonance Imaging), CT scanning after the intra-articular injection of contrast material and air can be useful for the diagnosis of patellofemoral osteoarthritis or loose bodies in a variety of joints. CT is also well suited for the demonstration of hip joint osteoarthritis. MRI can also depict many of the same findings of osteoarthritis as those depicted on radiographs, including joint-space narrowing, subchondral bony changes, and osteophytes. MRI and CT however, remain cost-prohibitive as compared to X-rays. MRI has the advantage of depicting cartilage directly and can be used to diagnose osteoarthritis in advance before its serious symptoms occur. (Zanetti, Bruder et al. 2000)

Treatment and Intervention

Several treatment options are now available for slowing or stopping the progression of osteoarthritis. The patient is instructed to avoid placing excessive strain on the affected joint and, if necessary, to lose weight. Physical therapy may be recommended to preserve joint motion and flexibility. Acetaminophen or acetylsalicylic acid (or other nonsteroidal anti-inflammatory drugs [NSAIDs]) are often prescribed to alleviate the pain associated with the disease. Cyclo-oxygenase-2 (COX-2) inhibitors are newer medications that are useful in patients who cannot tolerate NSAIDs due to stomach irritation and other gastro-intestinal factors.

Radiologists may also by administering image-guided intra-articular injections of steroids. This procedure often provides symptomatic relief for the patient and allows laboratory evaluation of the synovial fluid. Several corticosteroids are available for intra-articular injection.

If these treatments are ineffective, surgical intervention to resurface bones, reposition bones, replace joints and remove loose pieces of bones or cartilage is an important treatment option.

Self-Care, Better Attitude and Research

People with osteoarthritis can enjoy good health despite having the disease by learning self-care skills and developing a "good-health attitude." Self-care is central to successfully managing the pain and disability of osteoarthritis. Patients have a much better chance for a rewarding lifestyle when they educate themselves about the disease and take part in their own care. Working actively with a team of health care providers enables people with the disease to minimize pain, share in decision-making about treatment, and feel a sense of control over their lives. Research shows that patients who take part in their own care report less pain and make fewer doctor visits. They also enjoy a better quality of life.

Patients are generally encouraged to read, research and understand their affliction. Such a move keeps them involved and make for better general treatment.