Osteoarthritis

Template:Short description Template:Use dmy dates Template:Cs1 config Template:Infobox medical condition (new) Osteoarthritis is a type of degenerative joint disease that results from breakdown of joint cartilage and underlying bone.<ref>Template:Cite book</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> A form of arthritis, it is believed to be the fourth leading cause of disability in the world, affecting 1 in 7 adults in the United States alone.<ref>Template:Cite journal</ref> The most common symptoms are joint pain and stiffness.<ref name=NIH2015/> Usually the symptoms progress slowly over years.<ref name=NIH2015/> Other symptoms may include joint swelling, decreased range of motion, and, when the back is affected, weakness or numbness of the arms and legs.<ref name=NIH2015/> The most commonly involved joints are the two near the ends of the fingers and the joint at the base of the thumbs, the knee and hip joints, and the joints of the neck and lower back.<ref name=NIH2015/> The symptoms can interfere with work and normal daily activities.<ref name=NIH2015/> Unlike some other types of arthritis, only the joints, not internal organs, are affected.<ref name=NIH2015/>

Possible causes include previous joint injury, abnormal joint or limb development, and inherited factors.<ref name=NIH2015/><ref name=Lancet2015/> Risk is greater in those who are overweight, have legs of different lengths, or have jobs that result in high levels of joint stress.<ref name=NIH2015/><ref name=Lancet2015/><ref name=SBU2016 /> Osteoarthritis is believed to be caused by mechanical stress on the joint and low grade inflammatory processes.<ref name=Berenbaum2013>Template:Cite journal</ref> It develops as cartilage is lost and the underlying bone becomes affected.<ref name=NIH2015/> As pain may make it difficult to exercise, muscle loss may occur.<ref name=Lancet2015>Template:Cite journal</ref><ref name=NICE>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Diagnosis is typically based on signs and symptoms, with medical imaging and other tests used to support or rule out other problems.<ref name=NIH2015/> In contrast to rheumatoid arthritis, in osteoarthritis the joints do not become hot or red.<ref name=NIH2015/>

Treatment includes exercise, decreasing joint stress such as by rest or use of a cane, support groups, and pain medications.<ref name=NIH2015/><ref name=OARSI2014>Template:Cite journal</ref> Weight loss may help in those who are overweight.<ref name=NIH2015/> Pain medications may include paracetamol (acetaminophen) as well as NSAIDs such as naproxen or ibuprofen.<ref name=NIH2015>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Long-term opioid use is not recommended due to lack of information on benefits as well as risks of addiction and other side effects.<ref name=NIH2015/><ref name=OARSI2014/> Joint replacement surgery may be an option if there is ongoing disability despite other treatments.<ref name=Lancet2015/> An artificial joint typically lasts 10 to 15 years.<ref>Template:Cite journal</ref>

Osteoarthritis is the most common form of arthritis, affecting about 237Template:Nbspmillion people or 3.3% of the world's population as of 2015.<ref name=GBD2015Pre>Template:Cite journal</ref><ref name=Mar2014>Template:Cite journal</ref> It becomes more common as people age.<ref name=NIH2015/> Among those over 60 years old, about 10% of males and 18% of females are affected.<ref name=Lancet2015/> Osteoarthritis is the cause of about 2% of years lived with disability.<ref name=Mar2014/> Template:TOC limit

Signs and symptoms

File:Areas affected by osteoarthritis.gif

Osteoarthritis most often occurs in the hands (at the ends of the fingers and thumbs), neck, lower back, knees, and hips.

The main symptom is pain, causing loss of ability and often stiffness. The pain is typically made worse by prolonged activity and relieved by rest. Stiffness is most common in the morning, and typically lasts less than thirty minutes after beginning daily activities, but may return after periods of inactivity. Osteoarthritis can cause a crackling noise (called "crepitus") when the affected joint is moved, especially shoulder and knee joint. A person may also complain of joint locking and joint instability. These symptoms would affect their daily activities due to pain and stiffness.<ref>Template:Cite journal</ref> Some people report increased pain associated with cold temperature, high humidity, or a drop in barometric pressure, but studies have had mixed results.<ref name="pmid22124595">Template:Cite journal</ref>

Osteoarthritis 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 osteoarthritis progresses, movement patterns (such as gait), are typically affected.<ref name=NIH2015/> Osteoarthritis is the most common cause of a knee effusion.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

In smaller joints, such as at the fingers, hard bony enlargements, called Heberden's nodes (on the distal interphalangeal joints) 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. Osteoarthritis of the toes may be a factor causing formation of bunions,<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> rendering them red or swollen.

Causes

Damage from mechanical stress with insufficient self repair by joints is believed to be the primary cause of osteoarthritis.<ref name=Brandt2009/> Sources of this stress may include misalignments of bones caused by congenital or pathogenic causes; mechanical injury; excess body weight; loss of strength in the muscles supporting a joint; and impairment of peripheral nerves, leading to sudden or uncoordinated movements.<ref name=Brandt2009>Template:Cite journal</ref> The risk of osteoarthritis increases with aging, history of joint injury, or family history of osteoarthritis.<ref>Template:Cite journal</ref> However exercise, including running in the absence of injury, has not been found to increase the risk of knee osteoarthritis.<ref name=Bosomworth09>Template:Cite journal</ref><ref>Template:Cite journal</ref> Nor has cracking one's knuckles been found to play a role.<ref name="pmid21383216">Template:Cite journal</ref>

Primary

The development of osteoarthritis is correlated with a history of previous joint injury and with obesity, especially with respect to knees.<ref name="pmid11360143">Template:Cite journal</ref> Changes in sex hormone levels may play a role in the development of osteoarthritis, as it is more prevalent among post-menopausal women than among men of the same age.<ref name=NIH2015/><ref name="pmid21481553">Template:Cite journal</ref> Conflicting evidence exists for the differences in hip and knee osteoarthritis in African Americans and Caucasians.<ref>Template:Cite journal</ref>

Occupational

Template:See also Increased risk of developing knee and hip osteoarthritis was found among those who work with manual handling (e.g. lifting), have physically demanding work, walk at work, and have climbing tasks at work (e.g. climb stairs or ladders).<ref name=SBU2016>Template:Cite report</ref> With hip osteoarthritis, in particular, increased risk of development over time was found among those who work in bent or twisted positions.<ref name=SBU2016 /> For knee osteoarthritis, in particular, increased risk was found among those who work in a kneeling or squatting position, experience heavy lifting in combination with a kneeling or squatting posture, and work standing up.<ref name=SBU2016 /> Women and men have similar occupational risks for the development of osteoarthritis.<ref name=SBU2016 />

Secondary

Template:Multiple image This type of osteoarthritis is caused by other factors but the resulting pathology is the same as for primary osteoarthritis:

• Alkaptonuria<ref>Template:Cite journal</ref>
• Congenital disorders of joints<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

• Diabetes doubles the risk of having a joint replacement due to osteoarthritis and people with diabetes have joint replacements at a younger age than those without diabetes.<ref>Template:Cite journal</ref>
• Ehlers-Danlos syndrome<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

• Hemochromatosis and Wilson's disease<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

• 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 or ligaments (such as the ACL) as a result of an accident or orthopedic operations.
• Ligamentous deterioration or instability may be a factor.
• Marfan syndrome<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

• Obesity<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

• Joint infection<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref><ref>Template:Cite journal</ref><ref>Template:Cite journal</ref>

Pathophysiology

Template:Multiple image While osteoarthritis is a degenerative joint disease that may cause gross cartilage loss and morphological damage to other joint tissues, more subtle biochemical changes occur in the earliest stages of osteoarthritis progression. The water content of healthy cartilage is finely balanced by compressive force driving water out and hydrostatic and osmotic pressure drawing water in.<ref name="pmid25182679">Template:Cite journal</ref><ref name="Maroudas A 1976">Template:Cite journal</ref> Collagen fibres exert the compressive force, whereas the Gibbs–Donnan effect and cartilage proteoglycans create osmotic pressure which tends to draw water in.<ref name="Maroudas A 1976"/>

However, during onset of osteoarthritis, the collagen matrix becomes more disorganized and there is a decrease in proteoglycan content within cartilage. The breakdown of collagen fibers results in a net increase in water content.<ref name="Bollet AJ 1966">Template:Cite journal</ref><ref name="Brocklehurst R 1984">Template:Cite journal</ref><ref name="Chou MC 2009">Template:Cite journal</ref><ref name="Grushko G 1989">Template:Cite journal</ref><ref name="Mankin HJ 1975">Template:Cite journal</ref> This increase occurs because whilst there is an overall loss of proteoglycans (and thus a decreased osmotic pull),<ref name="Brocklehurst R 1984"/><ref name="Venn M 1977">Template:Cite journal</ref> it is outweighed by a loss of collagen.<ref name="Maroudas A 1976"/><ref name="Venn M 1977"/>

Other structures within the joint can also be affected.<ref>Template:Cite journal</ref> The ligaments within the joint become thickened and fibrotic, and the menisci can become damaged and wear away.<ref>Template:Cite journal</ref> Menisci can be completely absent by the time a person undergoes a joint replacement. 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 in the absence of the menisci. The subchondral bone volume increases and becomes less mineralized (hypo mineralization).<ref>Template:Cite journal</ref> All these changes can cause problems functioning. The pain in an osteoarthritic joint has been related to thickened synovium<ref>Template:Cite journal</ref> and to subchondral bone lesions.<ref>Template:Cite journal</ref>

Diagnosis

Template:Synovial fluid analysis Diagnosis is made with reasonable certainty based on history and clinical examination.<ref name="pmid19762361">Template:Cite journal</ref><ref name="pmid12180735">Template:Cite journal</ref> X-rays may confirm the diagnosis. The typical changes seen on X-ray include: joint space narrowing, subchondral sclerosis (increased bone formation around the joint), subchondral cyst formation, and osteophytes.<ref>Template:MerckManual</ref> Plain films may not correlate with the findings on physical examination or with the degree of pain.<ref name="Phillips">Template:Cite journal</ref>

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.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> These criteria were found to be 92% sensitive and 98% specific for hand osteoarthritis versus other entities such as rheumatoid arthritis and spondyloarthropathies.<ref name="pmid2242058">Template:Cite journal</ref>

• Osteo of the hand.jpg

  Severe osteoarthritis and osteopenia of the carpal joint and 1st carpometacarpal joint

• Gonarthrose-Knorpelaufbrauch.jpg

  MRI of osteoarthritis in the knee, with characteristic narrowing of the joint space

• Osteoarthritis left knee.jpg

  Primary osteoarthritis of the left knee. Note the osteophytes, narrowing of the joint space (arrow), and increased subchondral bone density (arrow).

• Damaged cartilage Danish sow.png

  Damaged cartilage from sows. (a) cartilage erosion (b) cartilage ulceration (c) cartilage repair (d) osteophyte (bone spur) formation.

• Primary osteoarthrosis (2) at knee joint.jpg

  Histopathology of osteoarthrosis of a knee joint in an elderly female

• Primary osteoarthrosis (5) at knee joint.jpg

  Histopathology of osteoarthrosis of a knee joint in an elderly female

• Health joint.png

  In a healthy joint, the ends of bones are encased in smooth cartilage. Together, they are protected by a joint capsule lined with a synovial membrane that produces synovial fluid. The capsule and fluid protect the cartilage, muscles, and connective tissues.

• Joint with severe osteoathritis.png

  With osteoarthritis, the cartilage becomes worn away. Spurs grow out from the edge of the bone, and synovial fluid increases. Altogether, the joint feels stiff and sore.

• Osteoarthritis.png

  Osteoarthritis

• Osteoarthritis -- Smart-Servier (cropped).jpg

  Bone (left) and clinical (right) changes of the hand in osteoarthritis

Classification

Template:Further A number of classification systems are used for gradation of osteoarthritis:

• WOMAC scale, taking into account pain, stiffness and functional limitation.<ref>Template:Cite journal</ref>
• Kellgren-Lawrence grading scale for osteoarthritis of the knee. It uses only projectional radiography features.
• Tönnis classification for osteoarthritis of the hip joint, also using only projectional radiography features.<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

File:Erosive osteoarthritis with gull-wing appearance, with seagull.jpg

X-ray of erosive osteoarthritis of the fingers, also zooming in on two joints with the typical "gull-wing" appearance

Both primary generalized nodal osteoarthritis and erosive osteoarthritis (EOA, also called inflammatory osteoarthritis) are sub-sets of primary osteoarthritis. EOA is a much less common, and more aggressive inflammatory form of osteoarthritis which often affects the distal interphalangeal joints of the hand and has characteristic articular erosive changes on X-ray.<ref name="pmid15454130">Template:Cite journal</ref>

Management

File:Exercise.png

Some kinds of exercise recommended for osteoarthritis

Lifestyle modification (such as weight loss and exercise) and pain medications are the mainstays of treatment. Acetaminophen (also known as paracetamol) is recommended first line, with NSAIDs being used as add-on therapy only if pain relief is not sufficient.<ref name=Cochrane10>Template:Cite journal Template:Open access</ref><ref name=Leo2019>Template:Cite journal</ref> Medications that alter the course of the disease have not been found as of 2018.<ref name="Disease-modifying drugs in osteoart">Template:Cite journal</ref> For overweight people, weight loss may help relieve pain due to hip arthritis.<ref name="Hip Osteoarthritis 2009"/> Recommendations include modification of risk factors through targeted interventions including 1) obesity and overweight, 2) physical activity, 3) dietary exposures, 4) comorbidities, 5) biomechanical factors, 6) occupational factors.<ref>Template:Cite journal</ref>

Successful management of the condition is often made more difficult by differing priorities and poor communication between clinicians and people with osteoarthritis. Realistic treatment goals can be achieved by developing a shared understanding of the condition, actively listening to patient concerns, avoiding medical jargon and tailoring treatment plans to the patient's needs.<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref>

Exercise

Weight loss and exercise provide long-term treatment and are advocated in people with osteoarthritis.<ref name="pmid19207981">Template:Cite journal</ref> Weight loss and exercise are the most safe and effective long-term treatments, in contrast to short-term treatments which usually have risk of long-term harm.<ref name="pmid30961569">Template:Cite journal</ref>

High impact exercise can increase the risk of joint injury, whereas low or moderate impact exercise, such as walking or swimming, is safer for people with osteoarthritis.<ref name="pmid19207981" /> A study has suggested that an increase in blood calcium levels had a positive impact on osteoarthritis. An adequate dietary calcium intake and regular weight-bearing exercise can increase calcium levels and is helpful in preventing osteoarthritis in the general population.Template:Citation needed There is also a weak protective effect factor of LDL (low-density lipoprotein) cholesterol. However, this is not recommended since an increase in LDL has an increased chance of cardiovascular comorbidities.<ref>Template:Cite journal</ref>

Moderate exercise may be beneficial with respect to pain and function in those with osteoarthritis of the knee and hip.<ref name="pmid23253613">Template:Cite journal</ref><ref>Template:Cite journal</ref><ref name=":0">Template:Cite journal</ref> These exercises should occur at least three times per week, under supervision, and focused on specific forms of exercise found to be most beneficial for this form of osteoarthritis.<ref name="pmid24574223">Template:Cite journal</ref>

While some evidence supports certain physical therapies, evidence for a combined program is limited.<ref name="pmid23128863">Template:Cite journal</ref> Providing clear advice, making exercises enjoyable, and reassuring people about the importance of doing exercises may lead to greater benefit and more participation.<ref name=":0" /> Some evidence suggests that supervised exercise therapy may improve exercise adherence,<ref>Template:Cite journal</ref> although for knee osteoarthritis supervised exercise has shown the best results.<ref name="pmid24574223" />

Physical measures

There is not enough evidence to determine the effectiveness of massage therapy.<ref name=nahin/> The evidence for manual therapy is inconclusive.<ref>Template:Cite journal</ref> A 2015 review indicated that aquatic therapy is safe, effective, and can be an adjunct therapy for knee osteoarthritis.<ref>Template:Cite journal</ref>

Functional, gait, and balance training have been recommended to address impairments of position sense, balance, and strength in individuals with lower extremity arthritis, as these can contribute to a higher rate of falls in older individuals.<ref name="pmid15517643">Template:Cite journal</ref><ref>Template:Cite journal</ref> For people with hand osteoarthritis, exercises may provide small benefits for improving hand function, reducing pain, and relieving finger joint stiffness.<ref>Template:Cite journal</ref>

A study showed that there is low quality evidence that weak knee extensor muscle increased the chances of knee osteoarthritis. Strengthening of the knee extensors could possibly prevent knee osteoarthritis.<ref>Template:Cite journal</ref>

Lateral wedge insoles and neutral insoles do not appear to be useful in osteoarthritis of the knee.<ref name="pmid23612781">Template:Cite journal</ref><ref name="pmid23989797">Template:Cite journal</ref><ref name=Cochrane2015>Template:Cite journal</ref> Knee braces may help,<ref>Template:Cite journal</ref> but their usefulness has also been disputed.<ref name=Cochrane2015 /> For pain management, heat can be used to relieve stiffness, and cold can relieve muscle spasms and pain.<ref name="url_Mayo Clinic">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Among people with hip and knee osteoarthritis, exercise in water may reduce pain and disability, and increase quality of life in the short term.<ref>Template:Cite journal</ref> Therapeutic exercise programs, such as aerobics and walking, may reduce pain and improve physical functioning for up to 6 months after the end of the program for people with knee osteoarthritis.<ref>Template:Cite journal</ref> Hydrotherapy might also be an advantage on the management of pain, disability and quality of life reported by people with osteoarthritis.<ref>Template:Cite journal</ref>

Thermotherapy

A 2003 Cochrane review of 7 studies between 1969 and 1999 found ice massage to be of significant benefit in improving range of motion and function, though not necessarily relief of pain.<ref name="pmid14584019">Template:Cite journal</ref> Cold packs could decrease swelling, but hot packs had no effect on swelling.<ref name="pmid14584019" /> Heat therapy could increase circulation, thereby reducing pain and stiffness, but with risk of inflammation and edema.<ref name="pmid14584019" />

Medication

Treatment recommendations by risk factors
GI risk	CVD risk	Option
Low	Low	citation	CitationClass=web }}</ref>
Moderate	Low	Paracetamol, or low dose NSAID with antacid<ref name="BBDNSAIDs"/>
Low	Moderate	Paracetamol, or low dose aspirin with an antacid<ref name="BBDNSAIDs"/>
Moderate	Moderate	Low dose paracetamol, aspirin, and antacid. Monitoring for abdominal pain or black stool.<ref name="BBDNSAIDs"/>

By mouth

The pain medication paracetamol (acetaminophen) is the first line treatment for osteoarthritis.<ref name="Cochrane10"/><ref name="OARSI2007">Template:Cite journal</ref> Pain relief does not differ according to dosage.<ref name=Leo2019/> However, a 2015 review found acetaminophen to have only a small short-term benefit with some concerns on abnormal results for liver function test.<ref>Template:Cite journal</ref> For mild to moderate symptoms effectiveness of acetaminophen is similar to non-steroidal anti-inflammatory drugs (NSAIDs) such as naproxen, though for more severe symptoms NSAIDs may be more effective.<ref name=Cochrane10/> NSAIDs are associated with greater side effects such as gastrointestinal bleeding.<ref name=Cochrane10/>

Another class of NSAIDs, COX-2 selective inhibitors (such as celecoxib) are equally effective when compared to nonselective NSAIDs, and have lower rates of adverse gastrointestinal effects, but higher rates of cardiovascular disease such as myocardial infarction.<ref name="pmid18405470">Template:Cite journal</ref> They are also more expensive than non-specific NSAIDs.<ref>Template:Cite journal</ref> Benefits and risks vary in individuals and need consideration when making treatment decisions,<ref>Template:Cite journal</ref> and further unbiased research comparing NSAIDS and COX-2 selective inhibitors is needed.<ref>Template:Cite journal</ref> NSAIDS applied topically are effective for a small number of people.<ref name="pmid27103611">Template:Cite journal</ref> The COX-2 selective inhibitor rofecoxib was removed from the market in 2004, as cardiovascular events were associated with long term use.<ref>Template:Cite journal</ref>

Education is helpful in self-management of arthritis, and can provide coping methods leading to about 20% more pain relief when compared to NSAIDs alone.<ref name="Hip Osteoarthritis 2009">Template:Cite journal</ref>

Failure to achieve desired pain relief in osteoarthritis after two weeks should trigger reassessment of dosage and pain medication.<ref>Template:Cite journal</ref> Opioids by mouth, including both weak opioids such as tramadol and stronger opioids, are also often prescribed. Their appropriateness is uncertain, and opioids are often recommended only when first line therapies have failed or are contraindicated.<ref name="OARSI2014"/><ref>Template:Cite journal</ref> This is due to their small benefit and relatively large risk of side effects.<ref name="ReferenceB">Template:Cite journal</ref><ref name=":4">Template:Cite journal</ref> The use of tramadol likely does not improve pain or physical function and likely increases the incidence of adverse side effects.<ref name=":4" /> Oral steroids are not recommended in the treatment of osteoarthritis.<ref name=OARSI2007/>

Use of the antibiotic doxycycline orally for treating osteoarthritis is not associated with clinical improvements in function or joint pain.<ref name=Nuesch2012>Template:Cite journal</ref> Any small benefit related to the potential for doxycycline therapy to address the narrowing of the joint space is not clear, and any benefit is outweighed by the potential harm from side effects.<ref name=Nuesch2012 />

A 2018 meta-analysis found that oral collagen supplementation for the treatment of osteoarthritis reduces stiffness but does not improve pain and functional limitation.<ref>Template:Cite journal</ref>

Topical

There are several NSAIDs available for topical use, including diclofenac. A Cochrane review from 2016 concluded that reasonably reliable evidence is available only for use of topical diclofenac and ketoprofen in people aged over 40 years with painful knee arthritis.<ref name="pmid27103611" /> Transdermal opioid pain medications are not typically recommended in the treatment of osteoarthritis.<ref name="ReferenceB"/> The use of topical capsaicin to treat osteoarthritis is controversial, as some reviews found benefit<ref name=Silva2011/><ref name="pmid19856319">Template:Cite journal</ref> while others did not.<ref name=PM09>Template:Cite journal</ref>

Joint injections

Use of analgesia, intra-articular cortisone injection and consideration of hyaluronic acids and platelet-rich plasma are recommended for pain relief in people with knee osteoarthritis.<ref>Template:Cite journal</ref>

Local drug delivery by intra-articular injection may be more effective and safer in terms of increased bioavailability, less systemic exposure and reduced adverse events.<ref>Template:Cite journal</ref> Several intra-articular medications for symptomatic treatment are available on the market as follows.<ref>Template:Cite journal</ref>

Steroids

Joint injection of glucocorticoids (such as hydrocortisone) leads to short-term pain relief that may last between a few weeks and a few months.<ref>Template:Cite journal</ref> A 2015 Cochrane review found that intra-articular corticosteroid injections of the knee did not benefit quality of life and had no effect on knee joint space; clinical effects one to six weeks after injection could not be determined clearly due to poor study quality.<ref>Template:Cite journal</ref> Another 2015 study reported negative effects of intra-articular corticosteroid injections at higher doses,<ref>Template:Cite journal</ref> and a 2017 trial showed reduction in cartilage thickness with intra-articular triamcinolone every 12 weeks for 2 years compared to placebo.<ref>Template:Cite journal</ref> A 2018 study found that intra-articular triamcinolone is associated with an increase in intraocular pressure.<ref>Template:Cite journal</ref>

Hyaluronic acid

Injections of hyaluronic acid have not produced improvement compared to placebo for knee arthritis,<ref name="Rutjes12">Template:Cite journal</ref><ref>Template:Cite journal</ref> but did increase risk of further pain.<ref name="Rutjes12" /> In ankle osteoarthritis, evidence is unclear.<ref>Template:Cite journal</ref>

Platelet-rich plasma

The effectiveness of injections of platelet-rich plasma (PRP) is unclear; there are suggestions that such injections improve function but not pain, and are associated with increased risk.Template:Vague<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref> A 2014 Cochrane review of studies involving PRP found the evidence to be insufficient.<ref>Template:Cite journal</ref>

Radiosynoviorthesis

Template:Further Injection of beta particle-emitting radioisotopes (called radiosynoviorthesis) is used for the local treatment of inflammatory joint conditions.<ref>Template:Cite journal</ref>

Radiotherapy

Low-dose radiotherapy has been shown to improve pain and mobility of affected joints, primarily in extremities. It is approximately 70-90% effective, with minimal side effects.<ref>Template:Cite journal</ref>

Ablation of knee sensory nerves

Radiofrequency ablation of sensory knee nerves, also called genicular neurotomy or genicular RFA, is an outpatient procedure used to reduce pain from knee osteoarthritis.<ref name="kidd">Template:Cite journal</ref><ref name="tran-22">Template:Cite journal</ref><ref name="conger">Template:Cite journal</ref>

In the procedure for genicular RFA, a guide cannula is first directed under local anesthesia and imaging (ultrasound or fluoroscopy) to each target genicular nerve, then the radiofrequency electrode is passed through the cannula, and the electrode tip is heated to about Template:Cvt for one minute to cauterize a small segment of the nerve.<ref name=kidd/> The heat destroys that segment of the nerve, which is prevented from sending pain signals to the brain.<ref name=kidd/>

As of 2023, reviews of clinical outcomes indicated that efficacy for reducing knee pain was achieved by ablating three or more branches of the genicular nerve (one of the articular branches of the tibial nerve).<ref name=kidd/><ref name=conger/><ref name="tran-23">Template:Cite journal</ref> Other sources indicate 4-5 genicular nerve targets may be justified for ablation to optimize pain relief,<ref name=tran-22/><ref name=conger/> while a 2022 analysis indicated that as many as 10 genicular nerve targets for RFA would produce better long-term relief of knee pain.<ref>Template:Cite journal</ref>

Knee pain relief of 50% or more following genicular RFA may last from several months to two years,<ref name=kidd/><ref name=tran-23/> and can be repeated by the same outpatient procedure when pain recurs.<ref name=kidd/>

Injection of phenol may be used as a neurolytic treatment of sensory knee nerves to relieve chronic pain from knee osteoarthritis.<ref name="tay">Template:Cite journal</ref><ref name="wilk">Template:Cite journal</ref>

Surgery

Bone fusion

Arthrodesis (fusion) of the bones may be an option in some types of osteoarthritis. An example is ankle osteoarthritis, in which ankle fusion is considered to be the gold standard treatment in end-stage cases.<ref name="pmid32940217">Template:Cite journal</ref>

Joint replacement

If the impact of symptoms of osteoarthritis on quality of life is significant and more conservative management is ineffective, joint replacement surgery or resurfacing may be recommended. Evidence supports joint replacement for both knees and hips as it is both clinically effective<ref name="pmid19057730">Template:Cite journal</ref><ref name="pmid22398175">Template:Cite journal</ref> and cost-effective.<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref> People who underwent total knee replacement had improved SF-12 quality of life scores, were feeling better compared to those who did not have surgery, and may have short- and long-term benefits for quality of life in terms of pain and function.<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref> The beneficial effects of these surgeries may be time-limited due to various environmental factors, comorbidities, and pain in other regions of the body.<ref>Template:Cite journal</ref>

For people who have shoulder osteoarthritis and do not respond to medications, surgical options include a shoulder hemiarthroplasty (replacing a part of the joint), and total shoulder arthroplasty (replacing the joint).<ref>Template:Cite journal</ref>

Biological joint replacement involves replacing the diseased tissues with new ones. This can either be from the person (autograft) or from a donor (allograft).<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> People undergoing a joint transplant (osteochondral allograft) do not need to take immunosuppressants as bone and cartilage tissues have limited immune responses.<ref>Template:Cite journal</ref> Autologous articular cartilage transfer from a non-weight-bearing area to the damaged area, called osteochondral autograft transfer system, is one possible procedure that is being studied.<ref>Template:Cite journal</ref> When the missing cartilage is a focal defect, autologous chondrocyte implantation is also an option.<ref>Template:Cite journal</ref>

Shoulder replacement

For those with osteoarthritis in the shoulder, a complete shoulder replacement is sometimes suggested to improve pain and function.<ref name=":2">Template:Cite journal</ref> Demand for this treatment is expected to increase by 750% by the year 2030.<ref name=":2" /> There are different options for shoulder replacement surgeries, however, there is a lack of evidence in the form of high-quality randomized controlled trials, to determine which type of shoulder replacement surgery is most effective in different situations, what are the risks involved with different approaches, or how the procedure compares to other treatment options.<ref name=":2" /><ref name=":5">Template:Cite journal</ref> There is some low-quality evidence that indicates that when comparing total shoulder arthroplasty over hemiarthroplasty, no large clinical benefit was detected in the short term.<ref name=":5" /> It is not clear if the risk of harm differs between total shoulder arthroplasty or a hemiarthroplasty approach.<ref name=":5" />

Other surgical options

Osteotomy may be useful in people with knee osteoarthritis, but has not been well studied and it is unclear whether it is more effective than non-surgical treatments or other types of surgery.<ref>Template:Cite journal</ref><ref name=":3" /> Arthroscopic surgery is largely not recommended, as it does not improve outcomes in knee osteoarthritis,<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref> and may result in harm.<ref>Template:Cite journal</ref> It is unclear whether surgery is beneficial in people with mild to moderate knee osteoarthritis.<ref name=":3">Template:Cite journal</ref>

Unverified treatments

Glucosamine and chondroitin

The effectiveness of glucosamine is controversial.<ref>Template:Cite journal</ref> Reviews have found it to be equal to<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref> or slightly better than placebo.<ref>Template:Cite report</ref><ref>Template:Cite journal</ref> A difference may exist between glucosamine sulfate and glucosamine hydrochloride, with glucosamine sulfate showing a benefit and glucosamine hydrochloride not.<ref>Template:Cite journal</ref> The evidence for glucosamine sulfate having an effect on osteoarthritis progression is somewhat unclear and if present likely modest.<ref>Template:Cite journal</ref> The Osteoarthritis Research Society International recommends that glucosamine be discontinued if no effect is observed after six months<ref>Template:Cite journal</ref> and the National Institute for Health and Care Excellence no longer recommends its use.<ref name=NICE/> Despite the difficulty in determining the efficacy of glucosamine, it remains a treatment option.<ref name=Hen2012>Template:Cite journal</ref> The European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO) recommends glucosamine sulfate and chondroitin sulfate for knee osteoarthritis.<ref>Template:Cite journal</ref> Its use as a therapy for osteoarthritis is usually safe.<ref name=Hen2012/><ref>Template:Cite journal</ref>

A 2015 Cochrane review of clinical trials of chondroitin found that most were of low quality, but that there was some evidence of short-term improvement in pain and few side effects; it does not appear to improve or maintain the health of affected joints.<ref name="pmid25629804">Template:Cite journal</ref>

Supplements

Avocado–soybean unsaponifiables (ASU) is an extract made from avocado oil and soybean oil<ref name=Cochrane2014>Template:Cite journal</ref> sold under many brand names worldwide as a dietary supplement<ref>Template:Cite journal</ref> and as a prescription drug in France.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> A 2014 Cochrane review found that while ASU might help relieve pain in the short term for some people with osteoarthritis, it does not appear to improve or maintain the health of affected joints.<ref name=Cochrane2014/> The review noted a high-quality, two-year clinical trial comparing ASU to chondroitin Template:Ndash which has uncertain efficacy in osteoarthritis Template:Ndash with no difference between the two agents.<ref name=Cochrane2014/> The review also found there is insufficient evidence of ASU safety.<ref name=Cochrane2014/>

A few high-quality studies of Boswellia serrata show consistent, but small, improvements in pain and function.<ref name=Cochrane2014/> Curcumin,<ref>Template:Cite journal</ref> phytodolor,<ref name=Silva2011/> and s-adenosyl methionine (SAMe)<ref name=Silva2011/><ref name="nahin">Template:Cite journal</ref> may be effective in improving pain. A 2009 Cochrane review recommended against the routine use of SAMe, as there has not been sufficient high-quality clinical research to prove its effect.<ref>Template:Cite journal</ref> A 2021 review found that hydroxychloroquine (HCQ) had no benefit in reducing pain and improving physical function in hand or knee osteoarthritis, and the off-label use of HCQ for people with osteoarthritis should be discouraged.<ref>Template:Cite journal</ref> There is no evidence for the use of colchicine for treating the pain of hand or knee arthritis.<ref name="Singh">Template:Cite journal</ref>

There is limited evidence to support the use of hyaluronan,<ref>Template:Cite journal</ref> methylsulfonylmethane,<ref name=Silva2011/> rose hip,<ref name=Silva2011>Template:Cite journal</ref> capsaicin,<ref name=Silva2011/> or vitamin D.<ref name=Silva2011/><ref>Template:Cite journal</ref>

Acupuncture and other interventions

While acupuncture leads to improvements in pain relief, this improvement is small and may be of questionable importance.<ref>Template:Cite journal</ref> Waiting list–controlled trials for peripheral joint osteoarthritis do show clinically relevant benefits, but these may be due to placebo effects.<ref name="pmid20091527">Template:Cite journal</ref><ref>Template:Cite journal</ref> Acupuncture does not seem to produce long-term benefits.<ref name="pmid18227323">Template:Cite journal</ref>

Electrostimulation techniques such as TENS have been used for twenty years to treat osteoarthritis in the knee. However, there is no conclusive evidence to show that it reduces pain or disability.<ref name="pmid19821296">Template:Cite journal</ref> A Cochrane review of low-level laser therapy found unclear evidence of benefit,<ref>Template:Cite journal Template:Retracted</ref>Template:Better source whereas another review found short-term pain relief for osteoarthritic knees.<ref>Template:Cite journal</ref>

Further research is needed to determine if balnotherapy for osteoarthritis (mineral baths or spa treatments) improves a person's quality of life or ability to function.<ref>Template:Cite journal</ref> The use of ice or cold packs may be beneficial; however, further research is needed.<ref name=Brosseau2002>Template:Cite journal</ref> There is no evidence of benefit from placing hot packs on joints.<ref name=Brosseau2002 />

There is low quality evidence that therapeutic ultrasound may be beneficial for people with osteoarthritis of the knee; however, further research is needed to confirm and determine the degree and significance of this potential benefit.<ref>Template:Cite journal</ref>

Therapeutic ultrasound is safe and helps reducing pain and improving physical function for knee osteoarthritis. While phonophoresis does not improve functions, it may offer greater pain relief than standard non-drug ultrasound.<ref>Template:Cite journal</ref>

Continuous and pulsed ultrasound modes (especially 1 MHz, 2.5 W/cm², 15min/ session, 3 session/ week, during 8 weeks protocol) may be effective in improving patients physical function and pain.<ref>Template:Cite journal</ref>

There is weak evidence suggesting that electromagnetic field treatment may result in moderate pain relief; however, further research is necessary and it is not known if electromagnetic field treatment can improve quality of life or function.<ref>Template:Cite journal</ref>

Viscosupplementation for osteoarthritis of the knee may have positive effects on pain and function at 5 to 13 weeks post-injection.<ref name=":1">Template:Cite journal</ref>

Epidemiology

File:Osteoarthritis world map - DALY - WHO2004.svg

CitationClass=web }}</ref> Template:Col-begin Template:Col-break Template:Legend Template:Legend Template:Legend Template:Legend Template:Legend Template:Legend Template:Legend Template:Col-break Template:Legend Template:Legend Template:Legend Template:Legend Template:Legend Template:Legend Template:Col-end

Globally, Template:As of, approximately 250Template:Nbspmillion people had osteoarthritis of the knee (3.6% of the population).<ref name="cross2014"/><ref name=LancetEpi2012>Template:Cite journal</ref> Hip osteoarthritis affects about 0.85% of the population.<ref name=cross2014>Template:Cite journal</ref>

Template:As of, osteoarthritis globally causes moderate to severe disability in 43.4 million people.<ref>Template:Cite book</ref> Together, knee and hip osteoarthritis had a ranking for disability globally of 11th among 291 disease conditions assessed.<ref name=cross2014/>

Middle East and North Africa (MENA)

In the Middle East and North Africa from 1990 to 2019, the prevalence of people with hip osteoarthritis increased threeTemplate:Ndashfold over the three decades, a total of 1.28 million cases.<ref>Template:Cite journal</ref> It increased 2.88-fold, from 6.16 million cases to 17.75 million, between 1990 and 2019 for knee osteoarthritis.<ref>Template:Cite journal</ref> Hand osteoarthritis in MENA also increased 2.7-fold, from 1.6 million cases to 4.3 million from 1990 to 2019.<ref>Template:Cite journal</ref>

United States

Template:As of, osteoarthritis affected 52.5 million people in the United States, approximately 50% of whom were 65 years or older.<ref name=cdc2016>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> It is estimated that 80% of the population have radiographic evidence of osteoarthritis by age 65, although only 60% of those will have symptoms.<ref name=Green2001>Template:Cite journal</ref> The rate of osteoarthritis in the United States is forecast to be 78 million (26%) adults by 2040.<ref name=cdc2016/>

In the United States, there were approximately 964,000 hospitalizations for osteoarthritis in 2011, a rate of 31 stays per 10,000 population.<ref>Pfuntner A., Wier L.M., Stocks C. Most Frequent Conditions in U.S. Hospitals, 2011. HCUP Statistical Brief #162. September 2013. Agency for Healthcare Research and Quality, Rockville, Maryland.{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> With an aggregate cost of $14.8 billion ($15,400 per stay), it was the second-most expensive condition seen in US hospital stays in 2011. By payer, it was the second-most costly condition billed to Medicare and private insurance.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref>Template:Cite book</ref>

Europe

In Europe, the number of individuals affected by osteoarthritis has increased from 27.9 million in 1990 to 50.8 million in 2019. Hand osteoarthritis was the second most prevalent type, affecting an estimated 12.5 million people. In 2019, Knee osteoarthritis was the 18th most common cause of years lived with disability (YLDs) in Europe, accounting for 1.28% of all YLDs. This has increased from 1.12% in 1990.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

India

In India, the number of individuals affected by osteoarthritis has increased from 23.46 million in 1990 to 62.35 million in 2019. Knee osteoarthritis was the most prevalent type of osteoarthritis, followed by hand osteoarthritis. In 2019, osteoarthritis was the 20th most common cause of years lived with disability (YLDs) in India, accounting for 1.48% of all YLDs, which increased from 1.25% and 23rd most common cause in 1990.<ref>Template:Cite journal</ref>

History

Etymology

Osteoarthritis is derived from the prefix osteo- (from Template:Langx) combined with arthritis (from {{#invoke:Lang|lang}}, Template:Transliteration, Template:Literal translation), which is itself derived from arthr- (from {{#invoke:Lang|lang}}, Template:Transliteration, Template:Literal translation) and -itis (from {{#invoke:Lang|lang}}, Template:Transliteration, Template:Literal translation), the latter suffix having come to be associated with inflammation.<ref>Template:Cite book</ref> The -itis of osteoarthritis could be considered misleading as inflammation is not a conspicuous feature. Some clinicians refer to this condition as osteoarthrosis to signify the lack of inflammatory response,<ref>Template:Cite journal</ref> the suffix -osis (from {{#invoke:Lang|lang}}, Template:Transliteration, Template:Literal translation) simply referring to the pathosis itself.

Other animals

Osteoarthritis has been reported in several species of animals all over the world, including marine animals and even some fossils; including but not limited to: cats, many rodents, cattle, deer, rabbits, sheep, camels, elephants, buffalo, hyena, lions, mules, pigs, tigers, kangaroos, dolphins, dugong, and horses.<ref name="Nganvongpanit Soponteerakul Kaewkumpai Punyapornwithaya 2017 pp. 140–155">Template:Cite journal</ref>

Osteoarthritis has been reported in fossils of the large carnivorous dinosaur Allosaurus fragilis.<ref name="molnar-pathology">Template:Cite book</ref>

Research

Therapies

Pharmaceutical agents that will alter the natural history of disease progression by arresting joint structural change and ameliorating symptoms are termed as disease modifying therapy.<ref name="Disease-modifying drugs in osteoart"/> Therapies under investigation include the following:

• Strontium ranelate – may decrease degeneration in osteoarthritis and improve outcomes<ref>Template:Cite book</ref><ref name="pmid19087296">Template:Cite journal</ref>
• Gene therapy – Gene transfer strategies aim to target the disease process rather than the symptoms.<ref>Template:Cite journal</ref> Cell-mediated gene therapy is also being studied.<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref> One version was approved in South Korea for the treatment of moderate knee osteoarthritis, but later revoked for the mislabeling and the false reporting of an ingredient used.<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref><ref name=Herald/> The drug was administered intra-articularly.<ref name="Herald">Template:Cite news</ref>

Cause

As well as attempting to find disease-modifying agents for osteoarthritis, there is emerging evidence that a system-based approach is necessary to find the causes of osteoarthritis.<ref>Template:Cite journal</ref> A study conducted by scientists at the University of Twente found that osmolarity induced intracellular molecular crowding might drive the disease pathology.<ref>Template:Cite journal</ref>

Diagnostic biomarkers

Guidelines outlining requirements for inclusion of soluble biomarkers in osteoarthritis clinical trials were published in 2015,<ref name=PMID25952342>Template:Cite journal</ref> but there are no validated biomarkers used clinically to detect osteoarthritis, as of 2021.<ref>Template:Cite book</ref><ref>Template:Cite journal</ref>

A 2015 systematic review of biomarkers for osteoarthritis looking for molecules that could be used for risk assessments found 37 different biochemical markers of bone and cartilage turnover in 25 publications.<ref name=PMID25963100>Template:Cite journal</ref> The strongest evidence was for urinary C-terminal telopeptide of type II collagen (uCTX-II) as a prognostic marker for knee osteoarthritis progression, and serum cartilage oligomeric matrix protein (COMP) levels as a prognostic marker for incidence of both knee and hip osteoarthritis. A review of biomarkers in hip osteoarthritis also found associations with uCTX-II.<ref name=PMID25623593>Template:Cite journal</ref> Procollagen type II C-terminal propeptide (PIICP) levels reflect type II collagen synthesis in body and within joint fluid PIICP levels can be used as a prognostic marker for early osteoarthritis.<ref>Template:Cite journal</ref>

External links

• {{#invoke:citation/CS1|citation

|CitationClass=web }}