Osteoarthritis of the knee describes a chronic, degenerative disease of the knee joints that is associated with cartilage damage, functional impairment and pain. The disease may be triggered by genetic predisposition, age, trauma or other pathological conditions.
Presentation
Patients usually present with inflamed knees and report pain that has been increasing with time. Of note, a sudden onset of knee pain is not an exclusion criterion for OA. Frequently, patients relate to experience more severe time after periods of rest, e.g. after getting up in the morning. In contrast, pain often eases during moderate activity. Sports and other activities accompanied by heaver knee loads enhance pain. Cold, rainy weather tends to aggravate symptoms.
Upon clinical examination, the affected knees result to be swollen and stiff, thus limiting joint movements. In some cases, the knees can be moved to a certain degree but may suddenly lock in a determined position. Cartilage flakes moving freely inside the synovial gap may be responsible for this kind of observations. They may also cause crepitus and pain [9] [10].
An individual patient may suffer from unilateral or bilateral OA of the knee. Whereas primary OA frequently affects both knees, this is not the case for secondary OA. Although the cause for the disease is different in primary and secondary OA, tissues undergo the same pathological changes. This distinction is therefore of minor clinical relevance.
Entire Body System
- Pain
The overall effect estimate of insoles on pain was a SMD of 0.992. The overall effect of bracing showed a significant reduction in pain of 1.34. [ncbi.nlm.nih.gov]
- Inflammation
[…] joint inflammation disease modifying antirheumatic drugs (DMARDs), which can specifically help with RA Injections that can help with knee arthritis include: hyaluronic acid supplements, which relieve arthritis inflammation and pain by lubricating the [healthline.com]
Let’s see what they’ve got to say: “Osteoarthritis is a common condition that causes pain and inflammation in a joint” There’s that word again: ’causes’! How can joint inflammation cause joint inflammation. [kinetic-revolution.com]
They help relieve pain and inflammation; however, they carry certain risks, such as stomach and kidney problems if used without proper monitoring by your doctor. [practicalpainmanagement.com]
Consequently, ABT-981 may provide clinical benefit to patients with inflammation-driven OA. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved. [ncbi.nlm.nih.gov]
It stabilizes pro-oxidant and antioxidant systems and also inflammation (Madrigal 2007). [diversityhealthcare.imedpub.com]
- Weakness
In conclusion, the use of NMES for quadriceps muscle weakness has been shown to improve muscle strength. [ncbi.nlm.nih.gov]
21–40 (moderate weakness), and 41–60 (mild weakness). [onlinelibrary.wiley.com]
Cartilage breakdown partly explains the degenerative nature of knee osteoarthritis, but a major part of the process is due to muscular weakness and loss of control. [apostherapy.co.uk]
While muscular weakness and deconditioning can result from osteoarthritis due to pain and decreased physical activity, muscle weakness also has an established causative role due to the muscles’ important role as active joint protectors. [startingstrength.com]
- Severe Pain
Several factors may make a person vulnerable to the disease ( Table 1 ). [aafp.org]
OTC medications are typically the first line of treatment to help you deal with knee osteoarthritis, while prescription medications are reserved for more severe pain. [practicalpainmanagement.com]
However, when people feel terrible pain that limits their ability to function normally, they should generally not try to "work through the pain." Moderate to severe knee pain is a signal that the joint needs a rest. [arthritis-health.com]
There is currently no cure for knee osteoarthritis, which can cause joint swelling, stiffness, and even severe pain. Doctors often prescribe pain relievers, such as acetaminophen, opioids, or nonsteroidal drugs, to help alleviate symptoms. [medicalnewstoday.com]
X-rays aren’t a good indicator of how much pain or disability you’re likely to have – some people have a lot of pain from minor joint damage but others have little pain from severe damage. [arthritisresearchuk.org]
- Short Stature
Symptoms * Bone cancer * Curved fifth fingers * Enlarged red blood cells * Dental decay * Short stature Causes * Abderhalden-Kaufmann-Lignac syndrome * Achalasia – addisonianism – alacrima syndrome * Achalasia – Addisonianism – Alacrimia syndrome * Achondrogenesis [checkorphan.org]
stature 59 32 frequent (33%) Frequent (79-30%) HP:0004322 6 clinodactyly of the 5th finger 59 32 occasional (7.5%) Occasional (29-5%) HP:0004209 7 radioulnar synostosis 59 32 occasional (7.5%) Occasional (29-5%) HP:0002974 8 clinodactyly 32 HP:0030084 [malacards.org]
stature Decreased body height Small stature [ more ] 0004322 5%-29% of people have these symptoms Clinodactyly of the 5th finger Permanent curving of the pinkie finger 0004209 Radioulnar synostosis Fused forearm bones 0002974 Percent of people who have [rarediseases.info.nih.gov]
Gastrointestinal
- Diarrhea
The most common adverse events associated with ABT-981 were diarrhea and headache in healthy subjects and injection site erythema in subjects with osteoarthritis of the knee. [ncbi.nlm.nih.gov]
[…] were not associated with MV among patients with GBS in this study, consistent with previous findings.1, 11 In Bangladesh, recent diarrhea among patients with GBS is mostly due to antecedent C. jejuni infection, which is associated with development of [onlinelibrary.wiley.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]
The most common side effects of NSAIDs involve gastrointestinal distress, such as stomach upset, cramping diarrhea, ulcers, and even bleeding. The risk of these and other side effects increases in the elderly. [medicinenet.com]
Cardiovascular
- Hypertension
Other potential side effects include be stomach ulceration (greatest in those with acid reflux, use corticosteroids, smokers, and those who drink alcohol), and renal damage (greatest in those older than 65, individuals with hypertension or congestive [pamf.org]
Be sure to tell your doctor if you have had a heart attack, stroke, angina, blood clot, hypertension, or if you are sensitive to aspirin, sulfa drugs or other NSAIDs. [orthoinfo.aaos.org]
Intriguingly, other well-studied mismatch diseases, such as hypertension, atherosclerotic heart disease, and type 2 diabetes ( 39 ), that also have become epidemic during the last few decades are strongly associated with knee OA ( 42 ), suggesting common [pnas.org]
Skin
- Ulcer
However, NSAIDs may be unsafe for people at high risk of developing ulcers, including people who have had ulcers in the past and the elderly. [drugs.com]
However, because of concerns about risks such as ulcers, GI bleeding, and loss of kidney function in long-term users, current guidelines recommend limiting the dose and treatment time. [arthritis.org]
NSAIDs can cause stomach ulcers, cardiovascular problems, and kidney and liver damage. Taking larger doses of acetaminophen may cause liver damage. Stage 3 OA is classified as “moderate” OA. [healthline.com]
“The problem with taking many over-the-counter pain relievers every day is that they increase your risk of developing stomach ulcers,” says Fiechtner. [prevention.com]
Musculoskeletal
- Knee Pain
[…] may cause the knee pain you’re feeling. [synviscone.com]
MATERIALS AND METHODS: Three hundred and sixty-five patients with knee pain underwent anterior-posterior (AP), PA flexed, lateral, and Merchant radiographs of the knee. [ncbi.nlm.nih.gov]
Knee Pain: What is Osteoarthritis? Spoiler: Osteoarthritis is the Knee Pain Bogeyman. [kinetic-revolution.com]
[…] and stabilise the knees Greater pain-free movement Improve circulation for knee-joint health post surgery Read More See how REVITIVE Arthritis-Knee helps people with knee pain to do more David suffers with Osteoarthritis of the knee and was due to have [revitive.com]
- Osteophyte
The participants who had osteophytes ≥1 mm 2 in the right, left, and bilateral knees were 15, 37, and 57 respectively, with osteophytes being significantly more common in the left knee. The OF was significantly larger in the left knee. [ncbi.nlm.nih.gov]
Occasionally, osteophytes were scored, but not narrowing, and these knees were included for definitions of OA that are osteophyte‐based. [academic.oup.com]
It is associated with abnormal bony overgrowths known as spurs, or osteophytes. As the cartilage wears out, spaces in the knee joint become narrower over time (seen on X-ray). [health.ucsd.edu]
[…] tibiofemoral compartment, and/or patellofemoral compartment 3 5 mm 7 weight-bearing radiographs will demonstrate more joint space narrowing than non-weight-bearing radiographs, hence affecting the radiographic severity 7,8 subchondral sclerosis marginal osteophytes [radiopaedia.org]
- Joint Stiffness
That’s because the joint space between bones is dramatically reduced—the cartilage is almost completely gone, leaving the joint stiff and possibly immobile. [healthline.com]
Whilst most experience relatively mild symptoms, for one in ten people, their knee pain and joint stiffness are debilitating. [apostherapy.co.uk]
Symptoms of osteoarthritis of the knee may include: pain that increases when you are active, but gets a little better with rest swelling feeling of warmth in the joint stiffness in the knee, especially in the morning or when you have been sitting for [webmd.com]
Most common complaints include joint swelling, joint stiffness, and pain. Knee osteoarthritis can be diagnosis via radiographs indicating boney cysts, narrowing joint space, and scelrosing of the bone. [physio-pedia.com]
One review found knee braces and foot orthoses helpful for reducing pain and joint stiffness and improving function in knee OA, without causing any adverse side effects. [arthritis.org]
- Back Pain
RESULTS: The cell-based product was well tolerated with few reported Adverse Events (mild arthralgia and low back pain). There was a relevant decrease in the intensity of pain since day 8 after the infusion, that was maintained after 12months. [ncbi.nlm.nih.gov]
These bicycles might be a good option for you if you also experience lower back pain because the recumbent position reduces the strain on your joints. [livestrong.com]
Eight studies reported increased knee or low back pain attributed to the exercise programme, and all identified studies reported no injuries. [cochrane.org]
Lieberman started wondering about arthritis a few years ago as he was compiling a list of diseases that modern humans aren't well-adapted to cope with — such as heart disease, lower back pain and nearsightedness. [npr.org]
pain, our focus is generally on its impact on the body—the back, the knees or the shoulders.… Read More Dr. [premierpain.com]
- Joint Swelling
The initial goals for this surgery are to restore muscle activity, to maintain the improved motion gained in surgery, and to try and minimize joint swelling after surgery. [drrobertlaprademd.com]
There is currently no cure for knee osteoarthritis, which can cause joint swelling, stiffness, and even severe pain. Doctors often prescribe pain relievers, such as acetaminophen, opioids, or nonsteroidal drugs, to help alleviate symptoms. [medicalnewstoday.com]
They also may experience joint stiffness after sitting for long periods of time or when waking up in the morning. Joint swelling may be present after extended periods of motion, as well. [healthline.com]
Arthritis is inflammation of one or more of your joints. 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.aaos.org]
Most common complaints include joint swelling, joint stiffness, and pain. Knee osteoarthritis can be diagnosis via radiographs indicating boney cysts, narrowing joint space, and scelrosing of the bone. [physio-pedia.com]
Psychiatrical
- Distractibility
Some of these creams contain counterirritants, such as wintergreen and eucalyptus, which stimulate the nerve endings and distract the brain from joint pain. These creams are often sold over the counter and are available in most drug stores. [arthritis-health.com]
Holla et al. found no association for frequent use of the pain coping strategy distraction, but found a significant association for infrequent use of the pain coping strategy worrying [ 20 ]. [arthritis-research.biomedcentral.com]
Currier reports the “5 clinical prediction rules for this study include: 1. hip and groin parasthesia 2. groin pain 3.passive knee flexion less than 122 degrees 4.passive hip IR less than 17 degrees 5.Pain with hip distraction”. [36] If the patient has [physio-pedia.com]
Neurologic
- Irritability
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]
Treatment-emergent adverse events (TEAEs), skin irritation, and vital signs were assessed and collected throughout the study. RESULTS: Of 260 patients randomized, 259 received ≥1 dose of study drug. [ncbi.nlm.nih.gov]
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]
Irritability, basically means, that if your pain is brought on, how long does it take to settle. If the pain goes immediately, it is of low irritability. If it takes hours or days to settle, it is of high irritability. [kinetic-revolution.com]
Pieces of cartilage may come loose and float inside the knee, further irritating the joint After a long period of time the cartilage can become completely “worn away” and the bones begin to rub together. [physicaltherapyweb.com]
- Seizure
[…] support the use of opioid therapy when other treatments have been ineffective or are inappropriate. 23 Tramadol (Ultram), with or without acetaminophen, decreases pain intensity, relieves symptoms, and improves function. 29 Tramadol increases the risk of seizure [aafp.org]
Workup
Anamnesis and clinical examination usually enable the physician to make a tentative diagnosis of OA. Radiographic imaging is the method of choice in order to confirm this diagnosis [11].
The most common findings in radiography are a reduced joint space and subchondral osseous cysts and sclerosis.
Alterations detected with imaging techniques usually concentrate in load-bearing areas. This might not be the case in other joint diseases.
Such findings may be confirmed in magnetic resonance imaging, but such an examination is usually not required. It may, however, be helpful to detect any damage to cartilage, menisci, tendons and muscles in close proximity to the knee, and to decide if a surgical intervention is necessary to repair such damage.
Other imaging techniques such as computed tomography or ultrasonography are currently of minor importance in OA diagnosis.
In order to differentiate OA of the knee from osteomyelitis, multiple myeloma and bone metastases of neoplasms, bone scans may be helpful [12]. The characteristic pattern observed in bones from OA patients is symmetric and shows only a slightly increased uptake of radionuclides.
Treatment
Treatment of OA aims at alleviating pain and recovering joint mobility. It is based on weight loss, moderate physical exercise and medication.
Overweight and obese patients may benefit significantly from weight loss [13]. Patients should also be advised to realize moderate and appropriate exercises in order to strengthen the muscles involved in leg movement. This way, the knee load lessens and pain eases.
Drug therapy mainly relies on analgesics and anti-inflammatory agents. Acetaminophen (paracetamol) and non-steroidal anti-inflammatory drugs such as ibuprofen and naproxen may considerably alleviate knee pain [14]. Patients treated with such drugs have to be warned about possible side effects that may result from prolonged or excessive intake. If such drugs are contraindicated or do not provide sufficient pain relief, corticosteroids may be administered. Corticosteroids and hyaluronic acid may also be injected intraarticularly [15].
Of note, current research studies focus on identifying receptors and intracellular pathways involved in joint inflammation and OA process. Agonists and antagonists may modulate these processes, ease symptoms and delay progress of cartilage and bone damage. Interleukin-17, for instance, has been found to be involved in joint inflammation [16].
Physical and occupational therapy may support medication treatment and muscle buildup. Patients may also benefit from wearing supportive braces.
If conservative therapy does not sufficiently alleviate symptoms, a knee arthroplasty may be required.
Prognosis
Only palliative treatment is available. According to current knowledge, there is no drug or surgical procedure that may revoke existing cartilage and bone damage.
The prognosis regarding disease progress worsens with age and advanced diseases states. If the disease also affects other joints, this is considered to affect progression in an unfavorable way [8].
Overweight and obesity may contribute to the exacerbation of the disease. Contrary to age, disease state and joint involvement, body weight may be adjusted in order to delay disease progress.
Knee arthroplasties have a good prognosis and success rates have been estimated to exceed 90%. However, additional surgical interventions may be necessary 10 to 15 years after the inicial joint replacement, particularly in young and active patients. They are usually not required in the elderly.
Etiology
While age is the most common cause of OA of the knee, there are several other factors that contribute to cartilage damage and that may provoke an early onset of symptoms and/or more severe tissue degeneration.
With age, cartilage degeneration occurs to a certain degree. Furthermore, the regenerative capacity of tissues decreases and possibly occurring traumas will have more severe consequences in older patients than in young ones. While older people usually present with primary OA, young people are generally diagnosed with secondary OA, i.e. they suffer from cartilage damage due to knee traumas or similar causes [2].
Some people are more susceptible to OA of the knee than others. Certain genetic disorders may either leave them more prone to knee joint degeneration or cause anatomical and physiological abnormalities that, in turn, change mechanical conditions in the knee and thus enhance degeneration.
People practicing certain sports, e.g., tennis, soccer or running, may also show an increased risk for developing OA of the knee. Weight lifting or movements like kneeling and squatting is associated with a constantly increased pressure on the knees and may also lead to joint degeneration. Such activities may not only be realized by athletes, but also by men and women practicing certain professions. It is important to note that exercise intensity does play a crucial role in determining whether sports mediate detrimental or beneficial effects. Indeed, people maintaining a sedentary lifestyle with little to no physical activity have very weak muscles around the knee and this condition augments the risk for OA of the knee.
Such a lifestyle - and various other factors - also affect body weight. Due to physical forces working on the knees, these joints will be stressed considerably with each pound of excess weight [3].
Finally, there are other diseases that increase the risk for OA of the knee. Such is the case with rheumatoid arthritis and certain metabolic disorders.
Epidemiology
Studies regarding disease prevalence are rather difficult to evaluate because there is no consensus regarding the definition of OA. Thus, the disease may be diagnosed based on clinical or radiographic criteria or any combination thereof. It has been estimated that in the United States there are about 20 million persons suffering from OA [4]. Although prevalence varies across distinct countries and their respective population, OA is the most common joint disease worldwide.
More than 50% of the population aged 65 or more does present radiographic alterations indicating OA of any joint. Some studies even report that this is the case for more than 80% of individuals older than 65 years. In the elderly, such alterations generally exist due to primary OA and do not involve clinical symptoms.
However, a significant share of patients suffering from OA of the knee does experience functional impairment and limitation of joint movement. People with severe OA of the knee may even depend on personal care.
Women are more prone to develop OA of the knee, as has been shown in a study focusing on females aged 55 and older [5].
Pathophysiology
Even though OA is referred to as a degenerative joint disease, inflammatory processes significantly affect tissue damage and disease progress. A variety of receptors, e.g. purinergic and interleukin receptors, mediate and regulate the release of cytokines and matrix metalloproteinases. Such events lead to an excessive matrix degeneration. Indeed, due to the importance of tissue inflammation for disease progress, it has been proposed to classify OA as an inflammatory disease rather than a degenerative condition. There is, however, consensus in that both degenerative and inflammatory processes contribute to joint damage and functional impairment.
OA of the knee is associated with cartilage degeneration. However, adjacent parts of the joint such as the synovial fluid, the subchondral bone of femur and tibia, the joint capsule and other tissues may be affected by mechanical stress or pathological conditions and trigger an early onset or more severe form of OA of the knee [6].
Cartilage damage triggers the chain of pathophysiological events leading to OA. Initially, chondrocytes increase proteoglycan synthesis in order to repair cartilage damage. This hypertrophic repair results in cartilage swelling. The affected knee may remain in this initial phase of OA for several years without any further disease progress. At some point, however, proteoglycan synthesis drastically decreases. Tissue properties change accordingly, the cartilage softens and loses elasticity. Vertical clefts and detached cartilage flakes become visible when the cartilage is examined microscopically and are a clear sign of integrity loss of the joint surfaces.
In the long term, this means joint space becomes increasingly narrow. Decreasing joint space is most frequently detected in the medial femorotibial joint compartment, but may also be observed in the lateral femorotibial and patellofemoral compartments. It may eventually lead to varus and valgus deformities.
Erosion continues until the whole cartilage layer is worn off and the subchondral bone is exposed. Because even in this advanced stage of OA knee movement continues, mechanical stress now affects the subchondral bone of femur and tibia and provokes structural changes also referred to as eburnation. They involve tissue vascularisation, an increase in cell density and an overall hardening and densification of the bone [7]. If there is an influx of synovial fluid into osseous tissue, osteoarthritic cysts may develop. Osseous necrosis may enhance the formation of such cysts, whose diameter may reach up to 20 mm.
Prevention
Summary
Osteoarthritis of the knee is a joint disease characterized by degenerative and inflammatory processes that commonly affects the elderly. Cartilage damage triggers osteoarthritis (OA) progress and may result from age or genetic predisposition, but also from overweight or traumas. OA is the most common joint disease [1].
In the course of the disease, knee joint cartilage erosion advances progressively. While cartilage swelling is observed during the initial phase of the disease, loss of cartilage integrity, fibrillation and detachment of flakes can be detected in advanced states of OA. Cartilage damage may proceed until the subchondral bone loses any protective layer and remains exposed. Bone sclerosis, vascularization, formation of osseous cysts and even osseous necrosis may result from excessive loads on subchondral bone tissue.
Only palliative treatment is available. Analgesics and anti-inflammatories may be administered in order to ease pain and reduce inflammation. Non-steroidal anti-inflammatory drugs may be helpful, but corticosteroids are also used to treat OA of the knee. Medication should be combined with weight loss, moderate physical activity, possibly guided by a physiotherapist.
If conservative treatment is not sufficient to alleviate symptoms, a surgical knee joint replacement may be required.
Patient Information
Osteoarthritis of the knee is characterized by knee pain and limited mobility that develops in the course of several years. Osteoarthritis (OA) is a very common joint disease that mainly affects older patients and may be detected in other joints as well.
Causes
The most common causes for OA of the knee are age and genetic predisposition. And while the majority of people will suffer from cartilage degeneration at some point in their life, certain lifestyle decisions may trigger an early onset of OA of the knee or more severe symptoms. In this context, overweight and obesity are the main risk factors. Also, certain activities involving heavy knee loads may exacerbate cartilage damage. Such is the case for intensive running, tennis, soccer and weight lifting, but also for determined professional activities that burden the knees. Traumas may also damage the cartilage of the knees and thus initiate disease progress.
Symptoms
Cartilage damage may lead to OA of the knee. In the course of the disease, the joint cartilage does lose integrity, cracks and decomposes. Small flakes of cartilage may even detach and move freely inside the joint. It may hinder knee movements and cause pain, similarly to a grain of sand in a gearbox. Furthermore, cartilage erosion deprives the underlying femur and tibia bones of its protective layer. Consequently, the bone tissue also suffers from pathophysiological modifications that also cause pain and further restrict mobility.
Therefore, impaired mobility and pain are the main symptoms of OA of the knee. Affected knees tend to be swollen and stiff. These symptoms may be more severe after prolonged rest or in the morning.
Diagnosis
In order to diagnose OA, the physician will obtain your medical history, conduct a clinical examination and X-ray your knees. When evaluating the patient's radiographic image, the physician will look out for narrowed joint spaces and alterations affecting the bone tissue.
Depending on your medical history, other diagnostic measures such magnetic resonance imaging may be taken in order to rule out lesions to menisci, tendons or joint capsules.
Treatment
Although commonly referred to as a degenerative joint disease, inflammatory processes significantly affect disease progress. Therefore, patients suffering from OA of the knees are usually prescribed analgesics and anti-inflammatory drugs. They may be taken orally or, in advanced cases, be injected directly into the knees.
It is of utmost importance to support medication therapy with weight loss, if indicated, and moderate physical activity to strengthen the muscles moving the knees. Patients may also benefit from wearing a brace.
If no such treatment is sufficient to alleviate symptoms associated with OA of the knee, surgery may be necessary to replace the knee joint.
References
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- Kirkley A, Birmingham TB, Litchfield RB, et al. A randomized trial of arthroscopic surgery for osteoarthritis of the knee. N Engl J Med. 2008; 359(11):1097-1107.
- Felson DT. Epidemiology of hip and knee osteoarthritis. Epidemiol Rev. 1988; 10:1-28.
- Pereira D, Peleteiro B, Araujo J, Branco J, Santos RA, Ramos E. The effect of osteoarthritis definition on prevalence and incidence estimates: a systematic review. Osteoarthritis Cartilage. 2011; 19(11):1270-1285.
- Roberts J, Burch TA. Osteoarthritis prevalence in adults by age, sex, race, and geographic area. Vital Health Stat 11. 1966; (15):1-27.
- Mankin HJ. The reaction of articular cartilage to injury and osteoarthritis (first of two parts). N Engl J Med. 1974; 291(24):1285-1292.
- Radin EL, Paul IL. Response of joints to impact loading. I. In vitro wear. Arthritis Rheum. 1971; 14(3):356-362.
- Chapple CM, Nicholson H, Baxter GD, Abbott JH. Patient characteristics that predict progression of knee osteoarthritis: a systematic review of prognostic studies. Arthritis Care Res (Hoboken). 2011; 63(8):1115-1125.
- Altman R, Asch E, Bloch D, et al. Development of criteria for the classification and reporting of osteoarthritis. Classification of osteoarthritis of the knee. Diagnostic and Therapeutic Criteria Committee of the American Rheumatism Association. Arthritis Rheum. 1986; 29(8):1039-1049.
- Wu CW, Morrell MR, Heinze E, et al. Validation of American College of Rheumatology classification criteria for knee osteoarthritis using arthroscopically defined cartilage damage scores. Semin Arthritis Rheum. 2005; 35(3):197-201.
- Recht MP, Goodwin DW, Winalski CS, White LM. MRI of articular cartilage: revisiting current status and future directions. AJR Am J Roentgenol. 2005; 185(4):899-914.
- Kraus VB, McDaniel G, Worrell TW, et al. Association of bone scintigraphic abnormalities with knee malalignment and pain. Ann Rheum Dis. 2009; 68(11):1673-1679.
- Felson DT, Zhang Y, Anthony JM, Naimark A, Anderson JJ. Weight loss reduces the risk for symptomatic knee osteoarthritis in women. The Framingham Study. Ann Intern Med. 1992; 116(7):535-539.
- Geba GP, Weaver AL, Polis AB, Dixon ME, Schnitzer TJ. Efficacy of rofecoxib, celecoxib, and acetaminophen in osteoarthritis of the knee: a randomized trial. Jama. 2002; 287(1):64-71.[published correction appears in JAMA. 2002; 287(8):989.]
- Bellamy N, Campbell J, Robinson V, Gee T, Bourne R, Wells G. Intraarticular corticosteroid for treatment of osteoarthritis of the knee. Cochrane Database Syst Rev. 2006; (2):CD005328.
- van Baarsen LG, Lebre MC, van der Coelen D, et al. Heterogeneous expression pattern of interleukin 17A (IL-17A), IL-17F and their receptors in synovium of rheumatoid arthritis, psoriatic arthritis and osteoarthritis: possible explanation for nonresponse to anti-IL-17 therapy? Arthritis Res Ther. 2014; 16(4):426.