knee arthritis treatment
filed in Uncategorized on Mar.05, 2010
Osteoarthritis (OA, also known as degenerative arthritis, degenerative joint disease), is a group of diseases and mechanical abnormalities involving degradation of joints, including articular cartilage and the subchondral bone next to it. Clinical manifestations of OA may include joint pain, tenderness, stiffness, creaking, locking of joints, and sometimes local inflammation. In OA, a variety of potential forces—hereditary, developmental, metabolic, and mechanical—may initiate processes leading to loss of cartilage -- a strong protein matrix that lubricates and cushions the joints. As the body struggles to contain ongoing damage, immune and regrowth processes can accelerate damage. When bone surfaces become less well protected by cartilage, subchondral bone may be exposed and damaged, with regrowth leading to a proliferation of ivory-like, dense, reactive bone in central areas of cartilage loss, a process called eburnation. The patient increasingly experiences pain upon weight bearing, including walking and standing. As a result of decreased movement because of the pain, regional muscles may atrophy, and ligaments may become more lax. OA is the most common form of arthritis, and the leading cause of chronic disability in the United States.
"Osteoarthritis" is derived from the Greek word "osteo", meaning "of the bone", "arthro", meaning "joint", and "itis", meaning inflammation, although the "itis" of osteo arthritis is somewhat of a misnomer -- inflammation is not a conspicuous feature of the disease. Osteoarthritis is not to be confused with rheumatoid arthritis, an autoimmune disease with joint inflammation as a main feature. A common misconception is that OA is due solely to wear and tear, since OA typically is not present in younger people. However, while age is correlated with OA incidence, this correlation may illustrate that OA is a process that takes time to develop -- or that repair and regeneration that may keep pace with damage in the joints of younger people do slow with age. There is sometimes a diagnosable underlying cause for OA, in which case it is described as secondary OA. In the majority of cases no cause can be identified, described as primary OA. "Degenerative arthritis" is often used as a synonym for OA, but the latter involves both degenerative and regenerative changes.
OA affects about 8 million people in the United Kingdom and nearly 27 million people in the United States, where it accounts for 25% of visits to primary care physicians and half of all NSAID (Non-Steroidal Anti-Inflammatory Drugs) prescriptions. It is estimated that 80% of the US population will have radiographic evidence of OA by age 65, although only 60% of those will show symptoms. In the United States, hospitalizations for osteoarthritis soared from about 322,000 in 1993 to 735,000 in 2006.
Classification
Osteoarthritis can be classified into either primary or secondary depending on if there is or is not an identifiable underlying cause.
Signs and symptoms
The main symptom is acute pain, causing loss of ability and often stiffness. "Pain" is generally described as a sharp ache, or a burning sensation in the associate muscles and tendons. OA can cause a crackling noise (called "crepitus") when the affected joint is moved or touched, and patients may experience muscle spasm and contractions in the tendons. Occasionally, the joints may also be filled with fluid. Humid and cold weather increases the pain in many patients.
OA commonly affects the hands, feet, spine, and the large weight bearing joints, such as the hips and knees, although in theory, any joint in the body can be affected. As OA progresses, the affected joints appear larger, are stiff and painful, and usually feel worse, the more they are used throughout the day, thus distinguishing it from rheumatoid arthritis.
In smaller joints, such as at the fingers, hard bony enlargements, called Heberden's nodes (on the distal interphalangeal joints) and/or Bouchard's nodes (on the proximal interphalangeal joints), may form, and though they are not necessarily painful, they do limit the movement of the fingers significantly. OA at the toes leads to the formation of bunions, rendering them red or swollen. Some people notice these physical changes before they experience any pain.
OA is the most common cause of joint effusion, sometimes called water on the knee in lay terms, an accumulation of excess fluid in or around the knee joint.
Causes
Exercise including running in the absence of injury has not been found to increase ones risks of developing osteoarthritis. Some investigators believe that mechanical stress on joints underlies all osteoarthritis, with many and varied sources of mechanical stress, including misalignments of bones caused by congenital or pathogenic causes; mechanical injury; being overweight; loss of strength in muscles supporting joints; and impairment of peripheral nerves, leading to sudden or uncoordinated movements that overstress joints.
Primary
This type of OA is a chronic degenerative disorder related to but not caused by aging, as there are people well into their nineties who have no clinical or functional signs of the disease. As a person ages, the water content of the cartilage decreases as a result of a reduced proteoglycan content, thus causing the cartilage to be less resilient. Without the protective effects of the proteoglycans, the collagen fibers of the cartilage can become susceptible to degradation and thus exacerbate the degeneration. Inflammation of the surrounding joint capsule can also occur, though often mild (compared to that which occurs in rheumatoid arthritis). This can happen as breakdown products from the cartilage are released into the synovial space, and the cells lining the joint attempt to remove them. New bone outgrowths, called "spurs" or osteophytes, can form on the margins of the joints, possibly in an attempt to improve the congruence of the articular cartilage surfaces. These bone changes, together with the inflammation, can be both painful and debilitating.
A number of studies have shown that there is a greater prevalence of the disease between siblings and especially identical twins, indicating a hereditary basis . Up to 60% of OA cases are thought to result from genetic factors.
Both primary generalized nodal OA and erosive OA (EOA. also called inflammatory OA) are sub-sets of primary OA. EOA is a much less common, and more aggressive inflammatory form of OA which often affects the DIPs and has characteristic changes on X-Ray.
Secondary
This type of OA is caused by other factors but the resulting pathology is the same as for primary OA:
- Congenital disorders of joints
- Diabetes.
- Inflammatory diseases (such as Perthes' disease), (Lyme disease), and all chronic forms of arthritis (e.g. costochondritis, gout, and rheumatoid arthritis). In gout, uric acid crystals cause the cartilage to degenerate at a faster pace.
- Injury to joints, as a result of an accident.
- Septic arthritis ( a infection of a joint )
- Ligamentous deterioration or instability may be a factor.
- Marfan syndrome
- Obesity
- Alkaptonuria
- Hemochromatosis and Wilson's disease
Diagnosis
There is no laboratory or pathological definition of osteoarthritis, and therefore no accepted laboratory tests to diagnose it. Diagnosis can often be made with reasonable certainty by clinical examination unless there is reason to suspect osteonecrosis or surgery is being considered, in which case imaging or blood tests may be necessary. Confirmation can be done through x-rays. This is possible because loss of cartilage, subchondral ("below cartilage") sclerosis, subchondral cysts from synovial fluid entering small microfractures under pressure, narrowing of the joint space between the articulating bones, and bone spur formation (osteophytes) - from increased bone turnover in this condition, show up clearly on x-rays. Plain films, however, often do not correlate well with the findings of physical examination of the affected joints or with the degree of pain. Usually other imaging techniques are not necessary to clinically diagnose osteoarthritis.
In 1990, the American College of Rheumatology, using data from a multi-center study, developed a set of criteria for the diagnosis of hand osteoarthritis based on hard tissue enlargement and swelling of certain joints. These criteria were found to be 92% sensitive and 98% specific for hand osteoarthritis versus other entities such as rheumatoid arthritis and spondyloarthropities .
Related pathologies whose names may be confused with osteoarthritis include pseudo-arthrosis. This is derived from the Greek words pseudo, meaning "false", and arthrosis, meaning "joint." Radiographic diagnosis results in diagnosis of a fracture within a joint, which is not to be confused with osteoarthritis which is a degenerative pathology affecting a high incidence of distal phalangeal joints of female patients.
Treatment
Treatment of OA consists of exercise, manual therapy, lifestyle modification, medication and other interventions to alleviate pain.