In general, patients suffering from arthritis of the knee show symptoms of joint inflammation. In most cases, e.g., in OAK and RA, these aggravate over longer periods of time, sometimes over the course of years. Infectious arthritis, for instance, may manifest suddenly.

Pain often dominates the clinical picture. The affected knees are swollen, mobility of the stiff joints is restricted. Patients often report symptoms to be more severe in cold weather conditions and after periods of rest, particularly when getting up in the morning [8]. Pain subsides upon realizing moderate physical activity, but intensifies if a certain threshold is surpassed. It can become unbearable and the patient's knees may buckle. Periarticular tissues may be tender, edematous and erythematous.

Cartilage flakes as often observed in OAK may cause crepitus and sudden locks of joint movement [9].

In RA, a pannus might be palpable.

Knee joint inflammation due to RA is usually milder than that observed in OAK patients. In contrast, RA might be accompanied by systemic symptoms such as weakness, fever, rheumatoid nodules and vasculitis, but these are not characteristic for OAK. Of note, extra-articular symptoms are considered poor prognostic parameters [10].

• Swelling

  Many can cause pain and swelling of the knee. Gout. [arthritis.org]

  Pain, swelling, and stiffness are the primary symptoms of arthritis. Any joint in the body may be affected by the disease, but it is particularly common in the knee. [orthoinfo.org]

  In cases of gouty arthritis of the knee, skin symptoms occur less often, however pain and swelling may be particularly intense. [en.wikipedia.org]

  It may also limit motion and cause swelling. This animation shows how arthritis affects the knee. Repetitive use of the joints over the years causes damage to the cartilage that leads to joint pain and swelling. [sharecare.com]

  Depending on the type of hip arthritis, symptoms can range from pain and swelling in the joints to difficulty using or moving the joint in a normal way. [northwell.edu]

• Inflammation

  It is called pannus and contributes to joint inflammation as well as cartilage and bone damage. The term arthritis of the knee describes an inflammation of the respective joint. [symptoma.com]

  In addition to causing inflammation in the knee and other joints, lupus can affect many organs, including the skin, heart, lungs, and kidney. Ankylosing spondylitis. [arthritis.org]

  Other healthy fats such as olive oil may also help to reduce inflammation and replace unhealthy fats in the diet. [livestrong.com]

  The knee may become affected by almost any form of arthritis.The word arthritis refers to inflammation of the joints. [en.wikipedia.org]

• Weakness

  A report published this week in the Journal of the American Medical Association (JAMA) offers weak-to-no proof that acupuncture helps ease the pain of knee arthritis. [health.harvard.edu]

  Weakness. Locking knee joint. Plica Plica syndrome occurs when bands of tissue in your knee, called plicae, swell from overuse or injury. The symptoms can include: Pain. Swelling. Clicking sensation in the knee Weakness Locking of the knee joint. [niams.nih.gov]

  Pain can discourage a person from being active, which can lead to joint stiffness and muscle weakness, which can lead to even more pain. [arthritis-health.com]

  The pain may often cause a feeling of weakness in the knee resulting in a locking or buckling sensation. People with knee arthritis often complain of worsening pain with changes in the weather. [sydneyknee.com.au]

• Weight Loss

  Assess weight and advise all overweight and obese persons to lose weight Review health benefits emphasizing the link between weight loss, exercise and improvement in joint pain Suggest an initial weight loss goal of 10% and a safe rate of weight loss [hopkinsarthritis.org]

  "What we found was both pathways were affected by weight loss." A 10% weight loss "can help people with knee osteoarthritis who are overweight or obese maintain their independence and have a good quality of life for the long term," he says. [usatoday.com]

  Does weight loss help with knee arthritis? Yes. Excess body weight is multiplied across the knee joint. [hipandknee.com]

• Severe Pain

  Types of knee braces for arthritis pain There are several different types of knee braces for arthritis pain: Basic knee sleeves Advanced braces and compression sleeves Unloader braces for severe cases Knee sleeves for arthritis are typically recommended [paindoctor.com]

  "The arthritis was so bad that I could barely step down without severe pain.” Because she wasn’t eligible for a knee replacement she tried cortisone injections, physical therapy, medications — nothing relieved her pain. [nbcnews.com]

  The condition, which can affect joints, can cause severe pain and limit mobility. Arthroscopic surgery is a common form of treatment for OA of the knee, but studies on its effectiveness have shown varying results. [edition.cnn.com]

  Refer for consideration of joint surgery before there is prolonged and established functional limitation and severe pain. [patient.info]

• Nausea

  However, it has some side effects such as nausea and diarrhea. Corticosteroids. These are available in pill form or via injections, and they’re used to control inflammation and pain. [healthline.com]

  However, these benefits were countered by significant side effects, including nausea, constipation, dizziness, sleepiness, and vomiting. [arthritis.org]

  The most common side effects of Tylenol are nausea, constipation and occasionally drowsiness. The most worrisome side effect from Tylenol is liver toxicity which is rare when the medication is taken as directed. [pamf.org]

  Ginger Ginger has been known to be helpful for a lot of things, especially nausea. What’s the one thing your mom whipped out every time you were feeling sick to your stomach when you were little? Ginger ale. Go figure. [rheumatoidarthritis.org]

• Diarrhea

  They have a number of minor side effects including upset stomach, diarrhea, and headache. [orthotrauma.com.au]

  However, it has some side effects such as nausea and diarrhea. Corticosteroids. These are available in pill form or via injections, and they’re used to control inflammation and pain. [healthline.com]

  A 2010 analysis found a small benefit for pain relief compared to placebo, but the drug also increased the risk for diarrhea. Though diacerein may be safer than NSAIDs, more high-quality studies are needed to confirm its effectiveness. [arthritis.org]

  […] and mask-like skin on the face numbness and pain in the feet pain, stiffness, and swelling of the wrist, fingers, and other joints dry cough, shortness of breath, and wheezing gastrointestinal problems, such as bloating after meals, constipation, and diarrhea [medicalnewstoday.com]

• Vomiting

  However, these benefits were countered by significant side effects, including nausea, constipation, dizziness, sleepiness, and vomiting. [arthritis.org]

• Vascular Disease

  Foot and Ankle Injuries Bunion and hammertoe Trauma, including fractures or soft tissue injuries like ankle sprain Tendon problems Diabetes Foot and ankle problems related to vascular disease Foot conditions related to athletic activities Hand and Wrist [sdsm.net]

• Arthritis

  Psoriatic arthritis. Psoriatic arthritis is a form of arthritis accompanied by the skin disease psoriasis. The skin disease often precedes the arthritis; in a small percentage the joint disease develops before the skin disease. Infectious arthritis. [arthritis.org]

  The major types of arthritis that affect the knee are osteoarthritis, rheumatoid arthritis, and posttraumatic arthritis. Osteoarthritis Osteoarthritis is the most common form of arthritis in the knee. [orthoinfo.org]

  Many forms of knee arthritis are chronic diseases. [symptoma.com]

  juvenile arthritis, and SLE-related arthritis, psoriatic arthritis, and ankylosing spondylitis), arthritis due to infectious causes (including Lyme disease-related arthritis), gouty arthritis, or reactive arthritis. [en.wikipedia.org]

• Knee Pain

  Osteoarthritis of the knee is painful because of inflammation. Over the last 5 years a new treatment for knee arthritis pain has emerged. This new treatment for arthritic knee pain is capable of decreasing your pain for 6 or more years. [howardluksmd.com]

  Arthritis is often the underlying cause of knee pain in absence of an injury. This article describes 6 types of arthritis that can affect the knee. Watch Causes of Knee Pain Video 1. [arthritis-health.com]

  Each person’s experience with chronic knee pain will be different. Temporary knee pain is different from chronic knee pain. Many people experience temporary knee pain as a result of an injury or accident. [healthline.com]

• Joint Stiffness

  In stage 4 the joint space between the bones are considerably reduced, causing the cartilage to wear off, leaving the joint stiff. [ibji.com]

  Affected joints might hurt during or after movement. Stiffness. Joint stiffness might be most noticeable upon awakening or after being inactive. Tenderness. Your joint might feel tender when you apply light pressure to or near it. [mayoclinic.org]

  […] finger joint pain joint pain treatment enthesitis arthritis in knee rheumatoid arthritis diagnosis seronegative arthritis ayurvedic treatment for arthritis juvenile arthritis rheumatoid nodules joint stiffness home remedies for joint pain joint pain [play.google.com]

  UW also suggests it is best to walk when you have the least pain and stiffness. Use modalities. If your knee is painful or stiff, warming the joint before you walk can be helpful. [livestrong.com]

  It causes inflammation as well as excess fluid in the joints. It often leads to destruction of the cartilage. Joints become swollen, painful and warm, and movement is limited by resultant stiffness. [knee-pain-explained.com]

• Joint Deformity

  RA degrades the lining of the joints and causes swelling that is painful and can lead to joint deformity in the affected joints. Rheumatoid arthritis tends to worsen over time. [advancedortho.org]

  behind the knee rheumatoid arthritis (RA) : a chronic autoimmune inflammatory disorder that causes painful swelling and can eventually cause joint deformity and bone erosion dislocation : dislocation of the kneecap most often the result of trauma meniscus [healthline.com]

  Joint symptoms may include: morning stiffness, lasting more than 1 hour pain, often in the same joints on both sides of the body loss of range of motion of joints, possibly with deformity Other symptoms include: chest pain when breathing in, due to pleurisy [medicalnewstoday.com]

• Arthralgia

  Joint pain is referred to as arthralgia. When four or more joints are involved, the arthritis is referred to as polyarthritis. When two or three joints are involved, it is referred to as oligoarthritis. [medicinenet.com]

• Irritability

  Skin irritation or swelling. The skin under the brace may become red and irritated if your knee brace fits poorly. Some people also experience swelling around the joint. Lack of benefit. [mayoclinic.org]

  Loose bodies, which consist of small chunks of cartilage wear or broken off bone spurs, can float in the knee and cause the joint to become very irritated. [drrobertlaprademd.com]

  Cement, asphalt or other hard surfaces may increase the stress on your knees and irritate them. Slow down if increasing your walking speed irritates your knee. [healthpages.org]

  If you experience increased pain, swelling, skin irritation, or any adverse reactions while using a Breg knee brace, immediately consult your medical professional. Breg knee braces will not prevent or reduce all injuries. [breg.com]

  However, these drugs can irritate the stomach. To prevent irritation, try coated aspirin or take medication with meals. [disabled-world.com]

Medical history and clinical examination allow for diagnosis of arthritis of the knee. However, in order to chose an adequate therapeutic scheme, the precise form of arthritis should be identified. Degenerative, autoimmune and infectious forms of gonarthritis will be treated differently.

While OAK may be limited to one side of the body, RA is a systemic disease that most frequently manifests symmetrically and affects several joints in different parts of the body. OAK is a typical disease of weight-bearing joints; RA symptoms are experienced in joints of hand and feet first before being felt in the larger joints such as the knees.

Plain radiography may give important hints as to the pathogenesis of the inflammation, but in early stages of the disease, tissue alterations may not yet be visible in radiographic images. Narrowing of the synovial space indicates loss of cartilage, areas of increased density point at remodelling processes in subchrondral osseous tissue. Bone cysts are visible as spots of diminished mineralization. Osteophytes are also readily recognizable on radiographic images. In order to assess the condition of soft tissues, magnetic resonance imaging or possibly computed tomography scans may be conducted.

A joint aspiration is not without risk but may provide further information that allows to distinguish between different forms of arthritis of the knee. In detail, inflammatory markers are often largely elevated in synovial fluid obtained from RA patients, while this is not the case for OAK samples. Leukocyte counts are significantly lower in OAK than in RA.

Mild to moderate cases of gonarthritis require medication therapy and lifestyle adaptions. Non-steroidal anti-inflammatory drugs are often the treatment of choice to provide relieve to pain and inflammation [11]. However, they may hardly delay progress of cartilage and bone damage if not accompanied by dietary modifications, physical activity and weight loss. Most patients will benefit from physical therapy and may learn specific exercises to strengthen knee-supporting muscles.

Only if these measures do not provide sufficient resolution of inflammatory symptoms, intra-articular injections of corticosteroids should be considered. Injection of hyaluronic acid has been reported to be beneficial, but such results still need further confirmation. Intra-articular injections are not long-term solutions.

In severe cases, drug therapy and exercises may not provide pain relieve. Partial or total knee arthroplasty may be an option for these patients. Here, either one or all three compartments of the knee joints are replaced by a metal or plastic implant [10].

Prognosis of arthritis of the knee is doubtful. At the time of diagnosis, cartilage and bone lesions are often advanced to irreversible states. Thus, complete cure is no longer achievable. However, effective medication is available to manage pain and other symptoms and enables most patients to manage their everyday life and realize physical activity. Other patients may need to undergo surgery in order to relieve pain. The outcome of such surgical interventions is generally good.

Although the specific causes of distinct forms of arthritis of the knee may differ or may not even be completely understood, there are certain general risk factors for such joint lesions. Any damage to the cartilage of the knee or to other structures of this joint may initiate a chain of pathophysiological events leading to permanent alterations and chronic gonarthritis. In this context, continuous excessive loads are most detrimental. They usually result from overweight and obesity, pathological conditions that particularly affect the weight-bearing joints of the lower limbs. Jobs requiring lifting of heavy weights and some sports are also associated with repetitive, heavy loads of the knees. These may be understood as a kind of minor but continuous trauma and they may have an effect similar to that of a single major insult. However, a sedentary lifestyle is not recommended either. Muscles supporting the knees should be trained and strengthened. Misalignment of skeletal structures may lead to an abnormally increased mechanical load on certain parts of the knees and damage them. Infection may trigger arthritis of the knee, too.

Although the aforementioned mechanisms may indeed provoke OAK and other forms of arthritis of the knee [1], it is unlikely that they trigger an autoimmune response that leads to RA. This becomes even clearer considering that the latter disease usually manifests in hand and feet joints first. Genetic factors, lifestyle decisions, immunological and endocrinological dysbalances have been proposed as possible causes of RA [2]. Tobacco consumption seems to be particularly detrimental for joint health [3]. It has to be noted though that the aforementioned risk factors for other forms of gonarthritis most certainly contribute to cartilage damage once the autoimmune response is initiated. Indeed, several forms of arthritis of the knee are mutually dependent. Age is a crucial risk factor for all types of gonarthritis [4].

In the United States, more than 50 million people are diagnosed with any form of arthritis every year. OAK and RA are among the most frequent forms of arthritis. Women are affected more frequently than men and pregnancy seems to trigger symptom onset of certain types of knee arthritis [2].

It has been estimated that more than one out of ten adults suffers from osteoarthritis, a significant share of these patients from OAK. Of note, arthritis of the knee may also affect children, but is more common in adults. While age is a major risk factor for any form of arthritis of the knee, other influencing factors such as tobacco consumption are more prevalent among the adult population and may partially explain the aforementioned observation.

RA affects more than one million patients in the United States and is therefore less frequently diagnosed than osteoarthritis. It has been estimated that 1/12 women and 1/20 men develops RA or similar autoimmune joint diseases at one point in their lives [5]. The mean age of RA patients is lower than those of individuals suffering from OAK.

Of note, overweight and obesity is a major health problem in the United States and most detrimental for knee health. Thus, the numbers given may not be representative of other geographical regions.

OAK and RA manifest with similar signs of joint inflammation, but develop through completely different pathomechanisms that shall be explained here as examples of pathogenesis of arthritis of the knee.

OAK is associated with complex cellular and biochemical processes that contribute to cartilage degeneration, altered mechanical stress, further progress of cartilage damage, appearance of vertical fissures and finally compromise of underlying bone tissue [6] [7]. Over the course of the disease, cartilage flakes may become lose, move freely throughout the synovial space. The cartilage layer becomes increasingly thinner, subchondral bone may be exposed and undergo pathologic remodelling processes. In this context, cysts may form in the osseous tissue. Osteophytes may develop and further restrict joint mobility.

While OAK develops due to "wear and tear", an autoimmune response accounts for RA. As has been mentioned above, genetic, intrinsic and environmental factors have been proposed as possible causes for RA, but its etiology has not yet been completely understood [2]. It is particularly unclear how the early immune response is triggered. Lymphocytes, initially T cells, later antibody-producing B cells, as well as synovial macrophages and a plethora of pro-inflammatory and matrix-degenerating cytokines are involved in establishing and amplifying the autoimmune reaction. Over the course of years, granulation tissue called pannus forms inside the knee. The pannus does not only hinder joint movement due to the space it's occupying, it also contributes actively to cartilage and bone damage.

While little can be done to change one's genetic heritage or to slow done the course of time, many risk factors for arthritis of the knee can be avoided. Most importantly, a healthy diet and an active lifestyle are guarantors of a healthy body weight and strengthened muscles that support the knees. Heavy loads should be avoided, both professionally as in recreational activities.

Underlying disorders, e.g., bone malformations or malalignment of skeletal elements, should be treated accordingly.

Arthritis of the knee is a rather general term referring to any inflammatory alteration of the respective joint. The term gonarthritis describes the same condition.

Arthritis of the knee may be triggered by distinct pathophysiological events and in this context, more than one hundred different forms of gonarthritis may be distinguished. The most common forms are osteoarthritis of the knee and rheumatoid arthritis and while this article will highlight certain common features of distinct forms, it will mainly focus on the aforementioned, specific types of gonarthritis.

This pathology is widely distributed and affects millions of people every year. It is associated with the characteristic signs of inflammation - pain, swelling, warmth, possibly redness of the surrounding tissues and functional impairment. The latter may be sufficiently severe to impede the affected individual to realize everyday activities.

Many forms of knee arthritis are chronic diseases. This does not apply for acute infectious forms of arthritis, but for those associated with permanent cartilage damage, possible erosion of the underlying bone and lesions to other structures of the knee joint. These pathological alterations are not reversible and only supportive treatment in form of analgesics and antiphlogistics can be provided.

Osteoarthritis of the knee (OAK) as well as rheumatoid arthritis (RA) are chronic forms of gonarthritis. For a long time, OAK has been considered a degenerative joint disease and has indeed been named gonarthrosis, although according to more recent findings, it should rather be classified as an inflammatory disorder. This disease is characterized by a slow, but progressive loss of cartilage integrity and subsequent erosion of the underlying bone. It is the most common form of arthritis of the knee. RA, on the other hand, is a systemic disease mediated by an autoimmune response. The vast majority of RA patients suffers from polyarthritis, where joints of hands and feet are typically affected first. RA rarely manifests as sole arthritis of the knee. Distinct types of immune cells, mainly synovial macrophages, initiate an immune response involving the formation of granulation tissue. It is called pannus and contributes to joint inflammation as well as cartilage and bone damage.

The term arthritis of the knee describes an inflammation of the respective joint. Such inflammation may have different causes and a total of more than one hundred forms of knee arthritis have been described. The most common ones are osteoarthritis of the knee (OAK) and rheumatoid arthritis (RA).

Causes

Distinct forms of arthritis have different triggers: While OAK is a degenerative disease with strong inflammatory features, RA is caused by an autoimmune response, i.e., by an immune response against tissues pertaining to the own body. Infectious arthritis, for instance, may be provoked by pathogens gaining access to the knee joints after traumatic injury or septicemia.

There are, however, common factors that contribute to arthritis of the knee:

• Overweight or obesity
• Sedentary lifestyle and weak muscles that are unable to support the knee
• Lifting of heavy weights, either due to job requirements or recreational activity
• Excess loads due to extreme athleticism
• Genetic factors
• Age

Symptoms

Inflamed knees are swollen and stiff. Their motion range is limited and bending and extending the leg is often painful. Pain may be more severe in cold weather and after periods of rest, particularly after getting up in the morning. Neighboring tissues may be tender, too.

Arthritis of the knee is often associated with inflammation of other joints.

Diagnosis

Knee inflammation may be diagnosed upon clinical examination. Further diagnostic measures are often necessary to identify its precise cause. To this end, radiographic images are usually taken. They may indicate changes to cartilage and the underlying bone. However, X-rays hardly permit to assess the condition of soft tissues. If the physician suspects damage to such structures, e.g., to the menisci, magnetic resonance imaging may be indicated.

Treatment

Mild to moderate cases are treated with analgesic and anti-inflammatory drugs as well as lifestyle adaptions. Overweight patients should reduce weight. In order to strengthen the muscles that may provide support to the knees, exercises should be carried out. They may be learned in physical therapy sessions.

If such treatment does not provide sufficient relieve, intra-articular injections of corticosteroids may be a second option.

Surgical partial or total knee replacement is only considered if no other measures provide freedom of pain.

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