Knee Pain Last updated: May 12, 2008

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  Knee Pain  
 

 
Conditions that suggest it | Contributing risk factors | Other conditions that may be present | Recommendations

 
 

Acute knee pain usually results from overuse, poor form during physical activity, not warming up or cooling down, or inadequate stretching. Simple causes of knee pain often clear up on their own with self care. Chronic knee pain can be a result of injury or disease. Being overweight can put you at greater risk for knee problems.

Knee pain can be caused by:

  • Arthritis - including rheumatoid, osteoarthritis, and gout, or other connective tissue disorders like lupus.
  • Bursitis - inflammation from repeated pressure on the knee (like kneeling for long periods of time, overuse, or injury).
  • Tendinitis - a pain in the front of your knee that gets worse when going up and down stairs or inclines. Happens to runners, skiers, and cyclists.
  • Baker's cyst - a fluid-filled swelling behind the knee that may accompany inflammation from other causes, like arthritis. If the cyst ruptures, pain in the back of your knee can travel down your calf.
  • Torn or ruptured ligaments or torn cartilage (a meniscus tear) -- can cause severe pain and instability of the knee joint.
  • Strain or sprain - minor injuries to the ligaments caused by sudden or unnatural twisting.
  • Dislocation of the kneecap.
  • Infection in the joint.
  • Knee injuries - can cause bleeding into your knee, which worsens the pain.
  • Hip disorders - may cause pain that is felt in the knee. For example, iliotibial band syndrome is injury to the thick band that runs from your hip to the outside of your knee.
  • Foot problems can result in poor tracking of the knee cap with pain.
  • Less common conditions that can lead to knee pain include bone tumor and Osgood-Schlatter disease

  
 

Conditions that suggest Knee Pain:
 
 
Symptoms - SkeletalCounter-indicators:
  Absence of knee pain
 
 

Risk factors for Knee Pain:
 
 
Autoimmune  Ankylosing Spondylitis

Musculo-Skeletal
  Osteoarthritis
  Rheumatoid Arthritis
 
 

Knee Pain suggests the following may be present:
 
 
Musculo-Skeletal  Joint Pain, General
 
 

Recommendations for Knee Pain:
 
 
Animal-based  Glucosamine / Chondroitin Sulfate
 A scientific review released by HHS' Agency for Healthcare Research and Quality (2007) concludes that evidence of benefit is lacking for many common ways of treating osteoarthritis of the knee, including popular dietary supplement ingredients, a common surgical procedure, and injected preparations.

The review found that glucosamine and chondroitin, over-the-counter dietary supplement ingredients that are used widely because of their purported benefits to relieve knee pain caused by osteoarthritis and improve physical functioning, appear to be no more effective than placebos. A placebo is a harmless substance given to selected patients in a clinical trial that looks like the real drug or injection being studied, but which has no medical effect.

The review, which was requested and funded by HHS' Centers for Disease Control and Prevention, also failed to find convincing evidence of benefit from arthroscopic surgery to clean the knee joint with or without removal of debris and loose cartilage.

Published studies generally report that injections with hyaluronan preparations (substances that are intended to improve lubrication of the knee joint) improve scores on patient questionnaires used to measure pain and function. However, the evidence is uncertain because of variation in study quality and difficulty determining whether changes in scores translate into real clinical improvements for patients.

"Millions of Americans seek relief from the pain and reduced mobility caused by osteoarthritis of the knee," said AHRQ Director Carolyn M. Clancy, M.D. "However, they should work with their clinicians to decide the best course of treatment for them based on what has and has not been proven to work."

Osteoarthritis is a widespread, costly disease that wears away the cartilage cushioning the knee joint, causing pain and reducing mobility. Arthritic diseases, which include osteoarthritis, affect an estimated 46 million people in the United States, and at age 64 and older, one in 10 Americans is estimated to have osteoarthritis of the knee. Osteoarthritis and related arthritic conditions cost more than $81 billion a year in medical care, lost wages, and other expenses.

The authors, who were led by David J. Samson, M.S., associate director of the AHRQ-supported Blue Cross and Blue Shield Association Evidence-based Practice Center in Chicago, reviewed findings from 53 randomized clinical trials of glucosamine, chrondroitin, and injections with hyaluronan preparations and 23 studies of arthroscopy. The review scrutinized individual studies concerned with these treatments' effects as well as meta-analyses that analyzed the combined evidence of groups of studies.

According to authors, better quality randomized clinical trials are needed to clarify whether these treatments are beneficial. However, given the aging of the population and increasing prevalence of obesity - both risk factors for osteoarthritis of the knee - "research on new approaches to prevention and treatment of osteoarthritis of the knee should be a high priority."

Diet
  Weight Loss
 Very attainable weight loss goals are sufficient to reduce pain and therefore motivate overweight patients with knee osteoarthritis to keep that weight off, according to research presented (November 13, 2006) at the American College of Rheumatology Annual Scientific Meeting in Washington, DC.

Weight gain dramatically multiplies the pounds of pressure and loading forces on the knee structure. Because this pressure leads to more wear and tear over time, body weight is considered one of the significant contributors to the onset and progression of knee osteoarthritis. Conversely, weight loss can relieve those realities.

Now, a long-term weight loss program has demonstrated that even modest weight loss contributed to improved quality of life in 30 mildly obese patients, and the resulting reduction in pain was so dramatic as to motivate their keeping the weight off.

Physical Medicine
  Physical Supports

Skin
  DMSO Topically
 Double-blind and other controlled studies have found a 25% DMSO gel effective for pain relief in osteoarthritis of the knee.

Surgery/Invasive
  Prolotherapy
  Hyaluronic Acid
 Physicians have injected hyaluronic acid directly into the synovial fluid in the knee as a treatment for osteoarthritis for the last 20+ years. There are many peer-reviewed articles written on the use of hyaluronic acid for this purpose. Further study is needed, as it remains to be proven that there is clear clinical benefit. Please see the link between knee pain and Glucosamine.

  Surgery
 A review in 2007, which was requested and funded by HHS' Centers for Disease Control and Prevention, failed to find convincing evidence of benefit from arthroscopic surgery to clean the knee joint with or without removal of debris and loose cartilage.
 
 


KEY
Strong or generally accepted link
Very strongly or absolutely counter-indicative
May do some good
Likely to help
Highly recommended

Take a look at America over a century ago (1904):
Only 14 percent of the homes in the U.S. had a bathtub.
Only 8 percent of the homes had a telephone.
A three-minute call from Denver to New York City cost only $11.
There were only 8,000 cars in the U.S. and only 144 miles of paved roads.
The maximum speed limit in most cities was 10 mph.





GLOSSARY

Acute:  An illness or symptom of sudden onset, which generally has a short duration.

Arthritis:  Inflammation of a joint, usually accompanied by pain, swelling, and stiffness, and resulting from infection, trauma, degenerative changes, metabolic disturbances, or other causes. It occurs in various forms, such as bacterial arthritis, osteoarthritis, or rheumatoid arthritis. Osteoarthritis, the most common form, is characterized by a gradual loss of cartilage and often an overgrowth of bone at the joints.

Bursitis:  The bursa is a fluid-filled pad that allows your muscles to easily slide over other muscles and bones. Bursitis occurs when this pad becomes inflamed. It usually occurs when you overuse or injure a specific joint, but it can also be caused by a bacterial infection. Symptoms include pain and inflammation around joints such as the elbow, hip, shoulder, big toe, ankle or knee.

Cartilage:  Specialized fibrous connective tissue that forms the skeleton of an embryo and much of the skeleton in an infant. As the child grows, the cartilage becomes bone. In adults, cartilage is present in and around joints and makes up the primary skeletal structure in some parts of the body, such as the ears and the tip of the nose.

Chronic:  Usually Chronic illness: Illness extending over a long period of time.

Cysts:  A closed pocket or pouch of tissue; a cyst may form within any tissue in the body and can be filled with air, fluid, pus, or other material. Cysts within the lung generally are air filled, while cysts involving the lymph system or kidneys are fluid filled. Cysts under the skin are benign, extremely common, movable lumps. These may develop as a result of infection, clogging of sebaceous glands, developmental abnormalities or around foreign bodies.

Gout:  A disease characterized by an increased blood uric acid level and sudden onset of episodes of acute arthritis.

Osgood-Schlatter Disease:  One of the most common causes of knee pain in young athletes. It causes swelling, pain and tenderness just below the knee, at the top of the shin bone (tibia). It occurs mostly in boys who are having a growth spurt. One or both knees may be affected.

Rheumatism:  General term applied to conditions of pain, or inability to articulate, various elements of the musculoskeletal system.