The Hip and Knee Book: developing an active management booklet for hip and knee osteoarthritis

. 2010 Feb 1;60(571):e64–e82. doi: 10.3399/bjgp10X483166

Evidence-based statements	Grade	Patient-centred messages
Diagnosis

Radiographic changes are only weakly associated with pain and disability in osteoarthritis of the knee. The results of knee x-rays should not be used in isolation when assessing patients with knee pain.⁴⁷	**	A diagnosis of osteoarthritis can be made without x-rays, and is based on patients' symptoms and examination findings.

Epidemiology – risk factors

There is moderate evidence of a greater incidence of osteoarthritis of the hip and knee in women. There is moderate evidence of a greater prevalence of osteoarthritis of the knee in women but not for osteoarthritis of the hip. In terms of osteoarthritis severity, there is moderate evidence that women had more severe knee osteoarthritis especially in the older than 55 years age group.⁵^,⁴³	**	We don't really know what causes the condition, and we don't know how to prevent it. There is no single cause, but various things are thought to be involved: Genetic factors are important — it seems some people are just more prone than others: osteoarthritis can run in families, and some types are more common in certain ethnic groups.
There is moderate evidence for a positive influence of obesity on the development of osteoarthritis of the hip.⁵^,³⁹	**
There is a moderate association between age and the prevalence of osteoarthritis, but osteoarthritis is not an inevitable consequence of ageing.⁵^,⁴⁰	**	People who are very overweight are at greater risk, and it is a little more common in women.
There is strong evidence of a positive relationship between work-related bending and knee osteoarthritis.³⁷	***	Various physical factors may play a part, but they do not have a consistent effect: previous damage to the joint surface, some physically intense occupations and sports, reduced muscle strength, abnormal joint shape or alignment. and the occurrence of osteoarthritis of the hip in men.⁵^,³⁸^,⁴⁶
There is a positive association between heavy physical workload in occupations such as farming or lifting weights heavier than 25 kg for more than 10 years³⁸	**
There is moderate evidence of a positive relationship between recreational and physical sporting activities and the occurrence of hip and knee pain, and the risk increases with the intensity and duration of exposure.⁵^,⁴¹	**	Age is obviously the main factor — painful osteoarthritis is uncommon in younger people. But that does not mean things inevitably get worse. Nor does it meant that all your joints will be affected.
The evidence that hip dysplasia influences the occurrence of hip osteoarthritis in older adults is limited.⁴²	*
Heritability is estimated to account for 40–60% for hip and knee osteoarthritis, although the responsible genes are unknown.⁵	*
There is a moderate association between hyaluronic acid serum levels and generalised osteoarthritis and radiological progression of knee osteoarthritis.⁴⁶	**

Epidemiology – prognostic factors

There is limited evidence that increased laxity, proprioceptive inaccuracy, older age, body mass index, and increased knee pain intensity are associated with deterioration of functional status in knee OA during the first three years of follow-up.⁴⁴	*	The pain you feel won't necessarily get worse – in about one-third of people with osteoarthritis of the hip or knee it actually improves. Of course, some things can make your pain worse, such as being overweight and letting your muscles get weak. Importantly though, there are also things that can help, such as regular exercise, keeping the muscles around the joint strong, keeping a positive attitude, believing that you are in control and can help yourself, and getting the support of friends and family.
There is limited evidence that greater muscle strength, better mental health, better self-efficacy, social support, and more aerobic exercise decrease the likelihood of functional deterioration in knee osteoarthritis.⁴⁴	*
There is limited evidence for a lack of association between functional status in the first three years of follow-up and joint alignment, sex, physical activity, role functioning, comorbidity, marital status, severity of osteoarthritis and bilateral disease in osteoarthritis of the knee.⁴⁴	*
There is conflicting evidence for an association between radiological change and functional status in the first three years of follow-up of knee osteoarthritis.⁴⁴	*
There is strong evidence that knee injury and regular sporting activities are not associated with radiological progression of knee osteoarthritis.⁴⁵	***
There is moderate evidence of a positive relationship between atrophic bone response and faster progression of hip osteoarthritis.⁴⁰	**
There is limited evidence for a more rapid progression of hip osteoarthritis when there is a superolateral progression of the femoral head compared with medial migration.⁴⁰	*
There is limited evidence for an absence of a relation between hip dysplasia and progression of hip osteoarthritis.⁴⁰	*
There is conflicting evidence for an association between female sex and progression of hip osteoarthritis.⁴⁰	*
Exercise

There is strong evidence that both strengthening and cardiovascular exercise are effective for reducing pain and improving function in the short-term in knee osteoarthritis.⁴^,⁵^,⁴⁸^–⁵⁰^,⁵²^,⁵³^,⁸²^,⁸⁴^,⁸⁵	***	We now know that inactivity and excessive rest is bad for hip or knee joints with osteoarthritis. Research confirms that once you have osteoarthritis regular moderate exercise does not make it worse — quite the reverse. Movement is good for you — and for your joints.
There is moderate evidence that no difference in effectiveness was found between different intensities of exercise for knee osteoarthritis.⁵¹	**	Your whole body must keep active to stay healthy. Regular physical activity: strengthens and stretches muscles around your joints, keeps you supple by getting stiff joints moving and stopping them seizing up, makes your bones stronger, works your heart and lungs to make you fit, releases natural chemicals that reduce pain and make you feel good, and puts you in control. That is why exercise is one of the core treatments for osteoarthritis. It is a way to treat yourself.
There is strong evidence that integrating self-management strategies with exercise is effective for reducing pain and improving function in knee osteoarthritis.⁵⁴^,⁵⁵	***
There is limited evidence that integrating self-management strategies with exercise is effective for reducing pain and improving function in hip osteoarthritis.⁵⁴	*
There is limited evidence that both strengthening and cardiovascular exercise are effective for reducing pain and improving function in the short term in hip osteoarthritis.⁴^,⁵^,⁴⁸^,⁵⁰^,⁵²	*

Weight loss

There is strong evidence that a 5% weight reduction will result in moderate improvement in disability in overweight patients with knee osteoarthritis.⁵^,⁸¹	***	If you are overweight, losing weight is very beneficial for your joints. Most people will notice an improvement in joint pain and function after losing 5% of their body weight.

Paracetamol

There is strong evidence that paracetamol has a small effect on pain and has few adverse reactions in osteoarthritis of the hip or knee compared with placebo, in the short term.⁵^,³³	***	There are many treatments that can help the pain. They may not remove the pain completely, but they can control it enough to let you get moving and active. Paracetamol is the simplest and safest painkiller. Take a regular dose rather than waiting for the pain to get too bad.

Topical non-steroidal anti-inflammatory drugs (NSAIDs)

There is moderate evidence that topical NSAIDs have a small effect on pain in knee osteoarthritis compared with placebo, and few adverse effects in the short term.⁵^,³²^,³⁴^,⁸³^,⁸⁵	**	Try massaging an anti-inflammatory gel directly over the painful joint – up to three time a day. It tends to be more effective for knee pain.

Prescribed medication — oral NSAIDs

There is strong evidence that oral NSAIDs have a small to moderate effect on pain in osteoarthritis of the hip and knee compared with placebo, in the short term.⁵^,²⁸^–³⁰^,³⁵^,⁸³^,⁸⁵	***	Anti-inflammatory tablets can be useful when paracetamol or the gels don't work. Ibuprofen is often prescribed but you can buy it over the counter: it works well. If it does not, it might be worth trying stronger anti-inflammatories such as diclofenac or naproxen, which have to be prescribed by your doctor. All drugs can have side-effects. Anti-inflammatory drugs can cause stomach ulcers.
There is moderate evidence that oral NSAIDs have a small additional benefit in terms of improving stiffness, physical function, and global assessment in knee and hip osteoarthritis compared with paracetamol.⁵^,²⁹^,³⁰^,⁸³	**
There is strong evidence that patients preferred NSAIDs compared with paracetamol.³⁰

Prescribed medication — opioids

There is moderate evidence that tramadol has a small to moderate effect in terms of pain and function in both short-and long-term treatment in hip and knee osteoarthritis compared with placebo.⁵^,³⁶^,⁸³^,⁸⁵	**	Stronger painkillers like codeine or tramadol can also be prescribed by your doctor. They are the same class of drug as morphine, but milder. They are often combined with paracetamol in the same tablet (e.g. co-codamol).

Thermotherapy

There is limited evidence for the benefit of local heat or cold for knee osteoarthritis in terms of pain and function.⁵^,⁶⁷^,⁸²	*	Heat or cold can be used for short-term relief of pain, particularly for flare ups.

There is limited evidence that ice massage can be used to improve range of movement and that cold packs can be used to decrease swelling.⁶⁷	*

Glucosamine

There is limited evidence that glucosamine may be effective and safe for improving pain and function in knee osteoarthritis and in delaying its progression.⁶⁹^–⁷²	*	The food supplement glucosamine sulphate taken in a single dose of 1.5 g may be helpful in improving pain and function.It is safe and worth trying.

Acupuncture

There is moderate evidence that acupuncture is safe and effective compared with placebo in terms of pain and function in patients with knee osteoarthritis, in the short-term.⁵^,⁷⁸^,⁸⁵	**	Acupuncture is safe and can reduce pain and improve function. Not everyone benefits, but it is worth trying a short course.

Transcutaneous electrical nerve stimulation (TENS)

There is moderate evidence that TENS has a moderate effect on reducing pain and stiffness in knee osteoarthritis.⁶⁴^,⁸²^,⁸⁵	**	TENS can be useful for reducing pain and stiffness in osteoarthritis and help you get moving and active.

Herbal remedies

There is moderate evidence that avocado-soybean unsaponifiables (ASU) may be effective for long-term symptomatic treatment of hip osteoarthritis and may help to reduce the consumption of NSAIDs.⁷⁶	**	Most of the many claims for herbal remedies are not backed up by scientific evidence.

There is limited evidence for other herbal medicines in terms of pain and function in knee and hip osteoarthritis.⁷⁵^–⁷⁷	*

Electrotherapy

There is no evidence that therapies such as laser, pulse electromagnetic therapy, ultrasound are more effective for osteoarthritis of the hip or knee in terms of pain and function, compared with placebo.⁵^,⁶³^,⁶⁵^,⁶⁸^,⁸²^,⁸³	*	Laser, pulse electromagnetic therapy, ultrasound are not effective.

Manual therapy

There is strong evidence for the benefit of manual therapy alone for hip OA in terms of pain and function compared with exercise.⁵^,⁸⁴	***	Manual therapy for OA hip includes stretching of shortened muscles around the hip joint and manual traction. Mobilising stiff joints and stretching shortened muscles, particularly around the hip joint by physiotherapists, osteopaths or chiropractors can be helpful.
There is moderate evidence that manual therapy combined with exercise is effective in terms of pain and function.⁸⁴	**

Aids and devices

There is limited evidence for bracing, joint supports or insoles in patients with biomechanical joint pain or instability.⁵^,⁷⁹^,⁸⁰^,⁸³^,⁸⁵	*	Sometimes the leg is not aligned properly, which will put extra strain on the joints — insoles can help. An unstable knee joint can be helped by a brace to support the joint.

Intra-articular steroid injections

There is strong evidence that intra-articular steroid injections were safe and provided short-term relief of pain in knee osteoarthritis up to 4 weeks post-injection.⁵^,⁵⁷^,⁵⁸^,⁶²^,⁸⁵	***	Steroid injections into joints can provide short-term pain relief and can be useful for settling flare ups.
There is limited evidence for the efficacy of intra-articular steroid injections for hip osteoarthritis.⁵	*

Viscosupplementation

Viscosuplementation appears to be safe and has a small effect on osteoarthritis of the knee in terms of pain, function, and patients'global assessment. However, it is unlikely to be cost-effective.⁵⁶^,⁵⁹^–⁶¹	*	Hyaluranon injections can improve lubrication inside the affected joint. But the small benefit only lasts up to three months.

Arthroscopic lavage and debridement

There is a lack of evidence for the effectiveness of arthroscopic lavage and debridement compared with tidal irrigation or placebo in terms of pain and function in knee osteoarthritis.⁵	*	Arthroscopy involves inserting a fibre-optic tube into the knee joint, washing out the joint, and sometimes trimming damaged cartilage. It does not give a lasting benefit in most cases of osteoarthritis.

Arthroplasty

There is strong evidence that restriction of referral for arthroplasty of osteoarthritis patients should not be based on body mass index, age or comorbidities.⁵	***	Joint replacement surgery is used when osteoarthritis is having a large effect on quality of life, and non-surgical treatments have failed to improve pain and function. It is best to have this surgery before there is long-term loss of function and severe pain. Old age, smoking, obesity, and other illnesses should not be barriers to referral for this operation

Key: evidence grade for the strength of scientific evidence:²⁵ ***strong — generally consistent findings provided by systematic review(s) of multiple high-quality studies. **moderate — generally consistent findings provided by review(s) of fewer or lower-quality studies. *weak — limited evidence: provided by a single high-quality study; conflicting evidence: inconsistent findings provided by review(s) of multiple studies.