Diagnosing Knee Osteoarthritis

Clinical guidelines (National Institute for Health and Care Excellence (UK), 2014)⁶ advocate that Osteoarthritis (OA) should be diagnosed clinically, without investigations, if a person:

• Is 45 or over and;
• Has activity-related joint pain and;
• Has no morning joint-related stiffness, or morning stiffness that lasts no more than 30 mins and;
• Red flags are not present and;
• An alternative diagnosis is unlikely.

X-rays and MRI do not change clinical management of OA Inappropriate use of imaging reinforces myths and misconceptions, increases likelihood of surgical intervention and reduces self-efficacy to self-manage

When are Investigations For OA Appropriate?

• To confirm a differential diagnosis
• To exclude another condition
• When there is an unusual clinical presentation
• MRI only useful for rare differential diagnoses (eg osteochondritis dissecans, avascular necrosis etc)

Red flags – Be aware of atypical features that may suggest another diagnosis:

• history of trauma
• prolonged morning joint-related stiffness
• rapid worsening of symptoms
• persistent night pain
• unexplained weight loss
• neurological symptoms or signs

Explaining a Diagnosis of Knee Osteoarthritis (OA) to a Patient

Do not to use the terms ‘wear and tear’ or ‘bone on bone’ as these types of descriptions can make patients lose hope about being able to self-manage their knee OA. It is much better to refer to the problem as ‘joint pain’ so that a patient becomes meaningfully engaged in the management of their disease. ‘Joint pain’ highlights the problem without conjuring up images of a hopeless structural problem that cannot be improved without surgery.

When discussing a diagnosis of osteoathritis (OA), the following terminology should be avoided as these phrases give the patient an inaccurate impression of the cause of the pain and/or prognosis of the condition:

• wear and tear
• progressive joint disintegration/degeneration/degradation
• bone on bone
• cartilage decay

How to Correctly Describe Osteoarthritis (OA)

It is not correct to describe Osteoarthritis (OA) as a simple process of wear and tear or overuse, as OA is an active condition (where the body responds to stimuli applied to the joint), rather than a simple wearing down of the joint. The pain associated with OA is more likely to result during the repair processes of knee tissue (eg cartilage, bones, synovium, ligaments and muscles), rather than simply from the loss of cartilage itself or the development of osteophytes and cysts at the margins of the joints.

A Positive Osteoarthritis​ (OA) Prognosis

It is more helpful for patients to focus on the problem at hand – joint pain. This reinforces to the patient that clinical management is aimed at dealing with pain and its consequences, without creating fear/anxiety about “joint damage” or an expectation of worsening the condition with further joint use. It is important to explain to patients that only a small proportion of people diagnosed with knee OA actually go on to require a joint replacement in the future and that early intervention can improve clinical outcomes.

_{Source: BMJ Learning (2016, June 15). Explaining osteoarthritis to patients video. YouTube}

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