Osteoarthritis (OA) is a clinical syndrome of joint pain accompanied by varying degrees of functional limitation and reduced quality of life. It is the most common form of arthritis and one of the leading causes of pain and disability worldwide. The most commonly affected peripheral joints are the knees, hips and small joints of the hands.
OA is characterised by localised loss of cartilage, remodelling of adjacent bone and associated inflammation. A variety of traumas may trigger the need for a joint to repair itself. OA includes a slow but efficient repair process that often compensates for the initial trauma, resulting in a structurally altered but symptom-free joint. However, in some people, because of either overwhelming trauma or compromised repair, symptomatic OA eventually presents. There is a great deal of variation in clinical presentation and outcome seen between different people, and also at different joints in the same person.
- OA is one of the most common chronic diseases, with an estimated overall prevalence in the general adult population of 11% for hip OA and 24% for knee OA, respectively.
- OA is age-related, with manifestations often not occurring until middle age.
- Genetic factors:
- Heritability estimates for hand, knee and hip OA are about 40-60%.
- The responsible genes are largely unknown.
- Constitutional factors:
- Female sex.
- High bone density - risk factor for development of OA.
- Low bone density - risk factor for progression of knee and hip OA.
- Local, largely biomechanical risk factors:
- Joint injury.
- Occupational and recreational stresses on joints.
- Reduced muscle strength.
- Joint laxity.
- Joint malalignment.
A diagnosis of OA can be made clinically without investigations if a person:
- Is aged 45 years or over; and
- Has activity-related joint pain; and
- Has either no morning joint-related stiffness or morning stiffness that lasts no longer than 30 minutes.
- Joint pain that is exacerbated by exercise and relieved by rest. Rest and night pain can occur in advanced disease. Knee pain due to OA is usually bilateral and felt in and around the knee. Hip pain due to OA is felt in the groin and anterior or lateral thigh. Hip OA pain can also be referred to the knee and, in males, to the testicle on the affected side.
- Joint stiffness in the morning or after rest.
- Reduced function and participation restriction.
- Reduced range of joint movement.
- Pain on movement of the joint or at extremes of joint movement.
- Joint swelling/synovitis (warmth, effusion, synovial thickening).
- Periarticular tenderness.
- Absence of systemic features such as fever or rash.
- Bony swelling and deformity due to osteophytes - in the fingers this presents as swelling at the distal interphalangeal joints (Heberden's nodes) or swelling at the proximal interphalangeal joints (Bouchard's nodes).
- Joint instability.
- Muscle weakness/wasting around the affected joint.
- Clinical examination: diagnosis is usually based on clinical examination.
- Plain X-rays: when disease is advanced it can be seen on plain X-rays. The diagnostic features that can be seen on X-ray are shown below:
- Body weight and body mass index: should be recorded.
- MRI: may be useful to distinguish other causes of joint pain.
- Blood tests: are normal in OA. Consider checking baseline FBC, creatinine and LFTs before starting a patient on non-steroidal anti-inflammatory drugs (NSAIDs).
- Joint aspiration: may be considered for swollen joints to exclude other causes such as septic arthritis and gout. See separate Joint Injection and Aspiration article.
- Knee OA: prepatellar bursitis, referred pain from the hip or spine.
- Hip OA: bursitis, referred pain from the knee or spine.
- OA of any joint: pseudogout, psoriatic arthritis, septic arthritis, viral arthritis, reactive arthritis, rheumatoid arthritis, gout, connective tissue disease, seronegative arthritis such as ankylosing spondylitis, referred pain, and medical conditions presenting with arthropathy (such as sarcoidosis and infective endocarditis).
Holistic approach to assessment and management
- The effect of OA on a person's function, quality of life, occupation, mood, relationships and leisure activities should be assessed. Consider:
- Current thoughts and beliefs - their concerns, expectations, knowledge about OA.
- Their support network - ascertain whether there is a carer and, if so, how the main supporter is coping (their ideas, concerns and expectations).
- Current mood (screen for depression) - determine whether there is any other stress.
- Pain assessment - ask what the patient has tried, including any drugs used (dose, side-effects, timing). Ask whether there are other treatable sources of pain (eg, periarticular pain, trigger finger, ganglion or bursitis). Enquire whether a chronic pain syndrome has developed.
- Promote function and reduce adverse effects on activities and sleep; referral to physiotherapy and/or occupational therapy may be indicated.
- Consider any comorbidities that may affect choice of treatment or fitness for surgery. Ask whether the patient is prone to falls - and whether this can be minimised.
- An annual review should be considered for any person with one or more of the following:
- Troublesome joint pain.
- More than one joint with symptoms.
- More than one comorbidity.
- Taking regular medication for OA.
These should be offered to everyone with OA:
- Education, advice and access to information: both oral and written information should be provided.
- Exercise: should be encouraged in all people with OA, regardless of their age, comorbidity, pain or disability. This should include exercise for general aerobic fitness and local muscle strengthening. As well as helping weight loss, exercise itself will help to build muscle strength and endurance and can lead to reduced pain and improved joint function. Physiotherapy may be useful.
- Weight loss advice: if the patient is overweight/obese. This will reduce the load on their joints and help to improve pain.
- The use of local heat or cold (thermotherapy) should be considered as an adjunct to core treatments.
- Aids and devices:
- Advice on appropriate footwear (including shock-absorbing properties) as part of core treatments for people with lower-limb OA.
- Biomechanical joint pain or instability: should be considered for assessment for bracing/joint supports/insoles as an adjunct to their core treatments.
- Assistive devices (eg, walking sticks and tap turners) should be considered as adjuncts to core treatments for people with OA who have specific problems with activities of daily living.
- Traditionally, paracetamol and/or topical NSAIDs should be considered ahead of oral NSAIDs, cyclo-oxygenase 2 (COX-2) inhibitors or opioids. However, a meta-analysis found that, on its own, paracetamol is ineffective for pain relief in OA.
- If paracetamol or topical NSAIDs are insufficient for pain relief for people with OA then the addition of opioid analgesics should be considered. Risks and benefits should be considered, particularly in older people.
- Topical treatments:
- Consider topical NSAIDs for pain relief in addition to core treatments for people with knee or hand OA.
- Topical capsaicin should be considered as an adjunct to core treatments for knee or hand OA.
- NSAIDs and highly selective COX-2 inhibitors:
- Where paracetamol or topical NSAIDs are ineffective for pain relief for people with OA then substitution with an oral NSAID/COX-2 inhibitor should be considered.
- Where paracetamol or topical NSAIDs provide insufficient pain relief for people with OA then the addition of an oral NSAID/COX-2 inhibitor to paracetamol should be considered.
- Use oral NSAIDs/COX-2 inhibitors at the lowest effective dose for the shortest possible period of time.
- When offering treatment with an oral NSAID/COX-2 inhibitor, the first choice should be either a standard NSAID or a COX-2 inhibitor (other than etoricoxib 60 mg). In either case, co-prescribe with a proton pump inhibitor (PPI).
- All oral NSAIDs/COX-2 inhibitors have analgesic effects of a similar magnitude but vary in their potential gastrointestinal, liver and cardio-renal toxicity; therefore, when choosing the agent and dose, take into account individual patient risk factors, including age. Consideration should be given to appropriate assessment and/or ongoing monitoring of these risk factors.
- If a person with OA needs to take low-dose aspirin, consider other analgesics before substituting or adding an NSAID or COX-2 inhibitor (with a PPI) if pain relief is ineffective or insufficient.
- Compared with placebo, glucosamine, chondroitin and their combination do not reduce joint pain or have an impact on narrowing of joint space. Glucosamine is not recommended for the treatment of OA.
- Intra-articular injections:
- Intra-articular corticosteroid injections should be considered as an adjunct to core treatments for the relief of moderate-to-severe pain in people with OA.
- Do not offer intra-articular hyaluronan injections for the management of OA.
- Topical herbal treatments: although topical capsaicin has been recommended as a treatment option, there is otherwise not a great deal of evidence from studies to show that herbal remedies are effective:
- Arnica gel probably improves symptoms as effectively as a gel containing an NSAID.
- Comfrey extract gel probably improves pain.
- There has been no strong evidence for capsicum extract gel.
Referral for consideration of joint surgery
- Ensure that the person has been offered at least the core (non-surgical) treatment options before referral.
- Base decisions on referral thresholds on discussions between patients, referring clinicians and surgeons, rather than using scoring tools for prioritisation.
- Do not refer for arthroscopic lavage and debridement as part of treatment for OA, unless the person has knee OA with a clear history of mechanical locking (as opposed to morning joint stiffness, 'giving way' or X-ray evidence of loose bodies).
- Consider referral for joint surgery for people with OA who experience joint symptoms (pain, stiffness and reduced function) that have a substantial impact on their quality of life and are refractory to non-surgical treatment.
- Refer for consideration of joint surgery before there is prolonged and established functional limitation and severe pain.
- Patient-specific factors (including age, sex, smoking, obesity and comorbidities) should not be barriers to referral for joint surgery.
These can include reduced mobility which can lead to problems with self-care and loss of employment.
- Most people affected by OA do not become severely disabled.
- Knee OA seems to have the worst prognosis with most cases deteriorating over a ten-year period. Hand OA has the best.
- A recent study has shown that generalised OA is associated with the radiological progression of knee OA. Knee pain, baseline radiological severity, sex, quadriceps strength, knee injury and regular sport activities did not seem to be related to the progression of OA in the knee.
- Weight control.
- Increasing physical activity.
- Avoiding injury.
- Improving education about OA, including increased use of expert patient programmes.
- Optimal management of symptoms by GPs to reduce the prevalence of disability due to OA.
Further reading and references
Day RO, Graham GG; Non-steroidal anti-inflammatory drugs (NSAIDs). BMJ. 2013 Jun 11346:f3195. doi: 10.1136/bmj.f3195.
Maricar N, Callaghan MJ, Felson DT, et al; Predictors of response to intra-articular steroid injections in knee osteoarthritis--a systematic review. Rheumatology (Oxford). 2013 Jun52(6):1022-32. doi: 10.1093/rheumatology/kes368. Epub 2012 Dec 22.
Platelet-rich plasma injections for osteoarthritis of the knee; NICE Interventional Procedure Guidance, May 2014
Scarpignato C, Lanas A, Blandizzi C, et al; Safe prescribing of non-steroidal anti-inflammatory drugs in patients with osteoarthritis - an expert consensus addressing benefits as well as gastrointestinal and cardiovascular risks. BMC Med. 2015 Mar 1913(1):55. doi: 10.1186/s12916-015-0285-8.
Osteoarthritis; NICE Quality Standard, June 2015
Osteoarthritis: care and management in adults; NICE Clinical Guideline (February 2014)
EULAR recommendations for the non-pharmacological core management of hip and knee osteoarthritis; Annals of Rheumatic Disease (April 2013)
Osteoarthritis; NICE CKS, April 2015 (UK access only)
Fransen M, McConnell S; Exercise for osteoarthritis of the knee. Cochrane Database Syst Rev. 2008 Oct 8(4):CD004376. doi: 10.1002/14651858.CD004376.pub2.
da Costa BR, Reichenbach S, Keller N, et al; Effectiveness of non-steroidal anti-inflammatory drugs for the treatment of pain in knee and hip osteoarthritis: a network meta-analysis. Lancet. 2016 May 21387(10033):2093-105. doi: 10.1016/S0140-6736(16)30002-2. Epub 2016 Mar 18.
Hochberg MC, Altman RD, April KT, et al; American College of Rheumatology 2012 recommendations for the use of nonpharmacologic and pharmacologic therapies in osteoarthritis of the hand, hip, and knee. Arthritis Care Res (Hoboken). 2012 Apr64(4):465-74.
Wandel S, Juni P, Tendal B, et al; Effects of glucosamine, chondroitin, or placebo in patients with osteoarthritis of hip or knee: network meta-analysis. BMJ. 2010 Sep 16341:c4675. doi: 10.1136/bmj.c4675.
British National Formulary (BNF); NICE Evidence Services (UK access only)
Cameron M, Chrubasik S; Topical herbal therapies for treating osteoarthritis. Cochrane Database Syst Rev. 2013 May 315:CD010538. doi: 10.1002/14651858.CD010538.
Belo JN, Berger MY, Reijman M, et al; Prognostic factors of progression of osteoarthritis of the knee: a systematic review of observational studies. Arthritis Rheum. 2007 Feb 1557(1):13-26.