Case of the Month #15: Chronic Knee Pain by Dr Kerry Bosworth

Education and individualised self-management strategies are recommended by NICE. Exercise is a core treatment with local muscle strengthening and general aerobic fitness. Weight loss should be encouraged if the patient is overweight or obese. Referral for consideration of joint surgery should occur before there is prolonged and established functional limitation and severe pain. Referral thresholds should be based on discussions between patient representatives, referring clinicians and surgeons rather than using scoring tools for prioritisation.
NICE also recommend local heat or cold, TENS and assistive devices such as walking sticks as an adjunct.

Paracetamol and/or topical NSAIDs are first line before oral NSAIDs or COX-2 inhibitors (with a proton pump inhibitor). If paracetamol or topical NSAIDs are insufficient, the risks and benefits of prescribing systemic NSAIDS or COX-2 inhibitors and opioid analgesics should be considered. Topical capsaicin and intra-articular corticosteroid injections can also be considered.

Intra-articular corticosteroid injection is a commonly performed procedure to reduce inflammation in the joint, although the usefulness of this intervention is much debated. The analgesic benefits may be felt after approximately a week and can last for many months. There is disagreement about the optimal frequency but the EULAR guidelines recommend no more than four injections in the same joint in a year. As with any corticosteroid injection, there may be a short-term worsening of hypertension and transient increased glycaemia as well as localised pain. Careful attention to aseptic technique is vital to avoid introducing infection into the joint.

NICE recommends that glucosamine, chondroitin and acupuncture are not offered for the management of osteoarthritis.
Although not covered by the NICE guideline, a genicular nerve block could be considered for intractable pain in knee osteoarthritis. Options include a local anaesthetic and corticosteroid nerve block or a radiofrequency (RF) procedure including conventional RF ablation, pulsed RF or cooled RF ablation. Targeted nerves include the superior medial, superior lateral and inferior medial genicular nerves. Ablation of the inferior lateral genicular nerves is often avoided because of their proximity to the common peroneal nerve.

Mrs J had found paracetamol and topical NSAIDs insufficient but was not keen to try an oral NSAID or COX-2 inhibitor due to previous gastritis. She was worried about potential side effects of opioids.
She had previously declined a referral to physiotherapy as she thought she would not be able to manage any exercises. She had also declined a referral for consideration of joint surgery, a decision she based on a bad experience of one of her friends.
She agreed to a referral for hydrotherapy and intra-articular steroid injections. Weight loss options available from the hospital were also suggested.