Knee Osteoarthritis
1. Introduction
Osteoarthritis is the most common form of arthritis and one of the leading causes of pain and disability worldwide. It can affect people at any age, but it is most common in people over 50 years of age (1). Almost any joint can be affected by osteoarthritis but it affects the knees most commonly, followed by the hips and the small joints of the hands (8). Patients often report pain accompanied by varying degrees of functional limitations and reduced quality of life. It can be diagnosed using the patient’s age, symptoms and a physical examination, with or without an X-ray. Exercise, education and weight loss improve symptoms and function in most patients with knee osteoarthritis and should be trialled initially.
Knee osteoarthritis is often described as ‘wear and tear’, implying that the joint has ‘worn out’. Symptoms and physical function are frequently assumed to be directly related to these ‘wear and tear’ changes, which might make you think that symptoms would worsen with further use. This is a common misconception as appropriately loading (exercising) the knee stimulates healing and is essential for joint health. Furthermore, ‘wear and tear’ changes do not always correspond with symptoms as people can have changes identified with imaging (X-ray and magnetic resonance imaging) but be pain-free (9).
Frequently Asked Questions
- All joints, including the knees, go through a cycle of damage and repair during their life. This process can cause changes in their structure and this is known as osteoarthritis.
- Osteoarthritis is the most common joint condition worldwide, affecting an estimated 10% of men and 18% of women over 60 years of age (7).
- The knee is the most affected joint in the body from osteoarthritis (6).
- Approximately 18% of the UK population aged over 45 years have sought treatment for osteoarthritis of the knee (8).
- No.
- Knee osteoarthritis is very common and often people will have no symptoms.
- You can have osteoarthritic related changes and be pain-free (9).
- With the right assessment, treatment and rehabilitation symptoms can be well managed.
- Osteoarthritis can affect anyone at any age, but it is more common in women over 50 years of age (7).
- People who are overweight are at an increased risk of suffering from osteoarthritis (7).
- Previous knee injury and family history of osteoarthritis can increase your risk of suffering from the condition.
Early-stage knee osteoarthritis:
- Pain is related to use.
- Relieved with rest but often feels worse at the end of the day.
- Modest swelling within the joint (effusion).
- Grating sensation (crepitus) whilst moving the knee.
Late-stage knee osteoarthritis:
- Pain can be more pronounced at night or persist at rest.
- Difficulty fully bending or straightening the knee.
- Bones may be enlarged and the legs can appear ‘bow-legged’.
- Seek advice from a musculoskeletal specialist.
- Try to keep active and complete regular exercises.
- Heat therapy.
- Over the counter medications can be taken if appropriate.
- Knee braces can help in certain cases.
- Maintain a healthy weight.
- There is no cure for osteoarthritis, but by taking a proactive approach you can significantly improve your symptoms (3).
- Flare-ups are common but will likely settle within a few months, especially if managed well.
- Learning to manage your symptoms, and keeping active and positive will give the best outcome in most instances.
We recommend consulting a musculoskeletal physiotherapist to ensure exercises are best suited to your recovery. If you are carrying out an exercise regime without consulting a healthcare professional, you do so at your own risk.
2. Signs and Symptoms
Early-stage knee osteoarthritis signs and symptoms:
- Pain tends to be related to using.
- Pain relieved with rest but often feels worse at the end of the day.
- Modest swelling within the joint (effusion).
- Grating sensation (crepitus) whilst moving the knee.
Late-stage knee osteoarthritis signs and symptoms:
- Pain might be worse at night and persist even at rest.
- Difficulty fully bending (flexing) or straightening (extending) the knee.
- Bones may be enlarged and the legs can appear ‘bow-legged’.
3. Causes
Abnormality in any of the knee tissues (e.g. cartilage, ligament, meniscus) can increase stress within the joint, which can contribute to tissue damage and subsequent repair. The repair process is slow but effective and can often make up for the initial damage. Several factors can influence joint stress and inhibit the repair process; the factors ultimately result in the breakdown of cartilage and bone within the joint.
4. Risk Factors
This is not an exhaustive list. These factors could increase the likelihood of someone developing knee osteoarthritis. It does not mean everyone with these risk factors will develop symptoms.
- Previous knee injury – might contribute to changes in joint structure and shape which can further exacerbate osteoarthritis changes.
- Age – increasing age is the strongest risk factor for developing osteoarthritis (7).
- Family history – there is evidence of a genetic influence of osteoarthritis.
- Obesity – increases the load on weight-bearing joints, increases the risk of developing knee osteoarthritis more than threefold and accelerates disease progression (7).
- Joint laxity and reduced muscle strength – may cause abnormal wear and joint loading (10).
- Being female – osteoarthritis is more common in women (7).
- Other conditions – this can happen when a joint is damaged from pre-existing complaints such as rheumatoid arthritis or gout.
5. Prevalence
Osteoarthritis is the most common joint disease worldwide, affecting an estimated 10% of men and 18% of women over 60 years of age (7). Approximately 18% of the UK population aged over 45 years have sought treatment for osteoarthritis of the knee (8).
6. Assessment & Diagnosis
Musculoskeletal physiotherapists and other appropriately qualified healthcare professionals can provide you with a diagnosis by obtaining a detailed history of your symptoms. A series of physical tests might be performed as part of your assessment to rule out other potentially involved structures and gain a greater understanding of your physical abilities to help facilitate an accurate working diagnosis.
Your treating clinician will want to know how your condition affects you day-to-day so that treatment can be tailored to your needs and personalised goals can be established. Intermittent reassessment will ascertain if you are making progress towards your goals and will allow appropriate adjustments to your treatment to be made. Imaging studies like an MRI (magnetic resonance imaging) or X-rays are not always required to achieve a working diagnosis, but in unusual or persistent presentations they may be warranted.
7. Self-Management
Education, exercise and weight management are core treatments for knee osteoarthritis irrespective of severity, age, disability or co-existing medical conditions (11). Self-management strategies should be developed with the individual, ensuring positive lifestyle changes are implemented alongside the core treatments and that they are maintained in the long term. You might also be advised to use over the counter medications such as pain relief/anti-inflammatories (prescribed by your GP).
8. Rehabilitation
It is not possible to prevent osteoarthritis changes altogether, but measures can be put in place to improve outcomes (3). Rehabilitation programmes should be performed 2-3 times per week for at least 12 weeks, but ideally maintained long term.
Below are three rehabilitation programmes created by our specialist physiotherapists targeted at addressing knee osteoarthritis. In some instances, a one-to-one assessment is appropriate to individually tailor targeted rehabilitation. However, these programmes provide an excellent starting point as well as clearly highlighting exercise progression. If weight-bearing exercises are not tolerated, lower weight-bearing alternatives could be trialled (e.g. aquatic exercise or bike).
9. Knee Osteoarthritis
Rehabilitation Plans
Our team of expert musculoskeletal physiotherapist have created rehabilitation plans to enable people to manage their condition. If you have any questions or concerns about a condition, we recommend you book an consultation with one of our clinicians.
What Is the Pain Scale?
The pain scale or what some physios would call the Visual Analogue Scale (VAS), is a scale that is used to try and understand the level of pain that someone is in. The scale is intended as something that you would rate yourself on a scale of 0-10 with 0 = no pain, 10 = worst pain imaginable. You can learn more about what is pain and the pain scale here.
This plan begins to create some movement within the knee to help with flexibility and begin the process of engaging the muscles. Pain should not exceed 3/10 on your self-perceived pain scale whilst completing this exercise programme.
- 0
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 910
In this plan, the exercises move towards more focus on strength of the thigh muscles which helps to reduce the stress on the knee. Pain should not exceed 4/10 on your self-perceived pain scale whilst completing this exercise programme.
- 0
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 910
Here we progress the strength exercises to try and maximise the thigh muscles to reduce stress and allow maximum function of the leg. Pain should not exceed 4/10 on your self-perceived pain scale whilst completing this exercise programme.
- 0
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 910
10. Return to Sport / Normal life
For patients wanting to achieve a high level of function or return to sport, we would encourage a consultation with a physiotherapist as you will likely require further progression beyond the advanced rehabilitation stage.
As part of a multi-modal treatment approach, your musculoskeletal physiotherapist may also use a variety of other pain-relieving treatments to support symptom relief and recovery. Whilst recovering you might benefit from a further assessment to ensure you are making progress and establish the appropriate progression of treatment.
11. Other Treatment Options
Corticosteroid injections may be considered if appropriate conservative management has failed. They may produce an improvement in pain and physical function, but effects are likely to decrease over time. Even if conservative management does not achieve a marked improvement, careful consideration is heavily encouraged as in some cases they cause more harm than good.
Surgery, including high tibial osteotomy and total knee replacement, might be options if conservative management fails in those that have a significant level of decreased physical function, discomfort and advanced osteoarthritis.
References
- Osteoarthritis: care and management. National Institute for Health and Care Excellence (NICE). www.nice.org.uk (Feb 2004).
- Vincent, H.K., Heywood, K., Connelly, J. & Hurley, R.W. (2012). Obesity and weight loss in the treatment and prevention of osteoarthritis. PM&R, 4(5), S59-S67.
- Anandacoomarasamy, A. & March, L. (2010). Current evidence for osteoarthritis treatments. Therapeutic advances in musculoskeletal disease, 2(1), 17-28.
- Lin, J., Zhang, W., Jones, A. & Doherty, M. (2004). Efficacy of topical non-steroidal anti-inflammatory drugs in the treatment of osteoarthritis: meta-analysis of randomised controlled trials. Bmj, 329(7461), 324.
- versusarthritis. (2018). Osteoarthritis (OA) of the knee. Available: https://www.versusarthritis.org/about-arthritis/conditions/osteoarthritis-of-the-knee. Last accessed 27th Feb 2021.
- Glyn-Jones, S., Palmer, A.J.R., Agricola, R., Price, A.J., Vincent, T.L., Weinans, H. & Carr, A.J., 2015. Osteoarthritis. The Lancet, 386(9991), pp.376-387.
- Arthritis Research UK. (2013). Osteoarthritis in general practice. Arthritis Research UK. http://www.arthritisresearchuk.org.
- Culvenor, A.G., Øiestad, B.E., Hart, H.F., Stefanik, J.J., Guermazi, A. & Crossley, K.M. (2019). Prevalence of knee osteoarthritis features on magnetic resonance imaging in asymptomatic uninjured adults: a systematic review and meta-analysis. British journal of sports medicine, 53(20),1268-1278.
- Aresti, N., Kassam, J., Nicholas, N. & Achan, P. (2016). Hip osteoarthritis. BMj, 354.
- Fernandes, L., Hagen, K.B., Bijlsma, J.W., Andreassen, O., Christensen, P., Conaghan, P.G.,…Lohmander, L.S. (2013). EULAR recommendations for the non-pharmacological core management of hip and knee osteoarthritis. Annals of the rheumatic diseases, 72(7), 1125-1135.
Other Conditions in
Knees, Long Term Conditions, Orthopaedics, Pain
Patellofemoral Pain Syndrome (PFPS)
Knee pain around the kneecap usually worse in static positions, squatting or kneeling.
Patellar Tendinopathy
Knee pain at the lower border of the kneecap which is also known as ‘jumper’s knee’.
Osgood-Schlatter Disease
Pain in an area just below the knee on the shin bone, often with a lump.
Meniscus Injury
Structural knee injury, triggered either by a tear or through wear and tear.
Knee Replacement Surgery
Replacement of the knee hinge joint, typically as a result of severe osteoarthritis or trauma.
Iliotibial Band Syndrome
Presents as pain on the outside of the knee, normally occurring because of overload due to prolonged or repeated bouts of exercise.
Femoral Nerve Radiculopathy
This is where the nerve that supplies the front of the leg is irritated and causes pain/numbess.
Fat Pad Impingement
A rare condition affecting the adipose (fat) tissue that sits under the kneecap (patella) between the joint spaces of the knee.
Degenerative Meniscus
Seen to be normal as we age, but in some situations can result in knee aches, pain or joint swelling.
Bowed Knees
A condition in which the legs are bowed outwards leaving a greater space in between your knees.
Benign Joint Hypermobility Syndrome
Common age related changes to the structure of the knee joint which may be associated with pain, stiffness and loss of function.
Baker’s Cyst
Swelling in the popliteal space (space behind the knee) that causes a visible lump.
Anterior Cruciate Ligament (ACL) Injury
Injury to a major stability ligmant in the knee, normally occuring following a significant twisting injury.