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Referral should be when other pre-existing medical conditions have been optimised AND Conservative measures have been exhausted and failed. This will include weight reduction, NSAIDs and analgesics, changing activity, and introducing a walking aid
Please refer to the classification of pain levels and functional limitations in the table below.
Referrals should be made if any one of the three following applies:
The patient is fit for surgery with a BMI ≤30. Patients with a BMI >30 should be advised and given appropriate support to address lifestyle factors that would improve their fitness for surgery
There is evidence to show that "Weight loss and exercise combined have been shown to achieve the same level of symptom relief as joint replacement surgery".
BMI is an established measure of weight though it is recognised that muscular people will have a higher BMI that is not thought to be a risk to health (muscle is denser than fat)
Referrals will not be accepted if the patient has an Oxford Knee Score greater than or equal to 20. This scoring should be completed in Primary Care prior to referral.
Patients should make shared decisions with clinicians, using decision support such as the NHS Decision Aid for knee osteoarthritis
Evidence suggests that the following patients would be INAPPROPRIATE candidates for knee joint replacement surgery:
Patients whom are assessed by the above criteria to be inappropriate for knee replacement surgery should not be listed for surgery.
For Knee Replacement: Classification of Mobility, Stability, Symptomatology, Radiology and Localisation
Around 450 patients per 100,000 population will present to primary care with hip pain each year. Of these, 25% will improve within three months and 35% at twelve months; this improvement is sustained8.
20% of adults over 50 and 40% over 80 years report disability from knee pain secondary to osteoarthritis9. The majority of patients present to primary care with symptoms of pain and stiffness, which reduces mobility and with associated reduction in quality of life.
Osteoarthritis may not be progressive and most patients will not need surgery, with their symptoms adequately controlled by non-surgical measures, as outlined by NICE3. Symptoms progress in 15% of patients with hip pain within 3 years and 28% within 6 years8.
When patient's symptoms are not controlled by up to 3 months of non-operative treatment they become candidates for assessment for joint surgery. The decision to have joint surgery is based on the patient's pre-operative levels of symptoms, their capacity to benefit, their expectation of the outcome and attitude to the risks involved. Patients should make shared decisions with clinicians, using decision support such as the NHS Decision Aid for knee osteoarthritis9
Obesity is an increasing problem in the population and also a significant risk factor for osteoarthritis. It is often associated with comorbidities such as diabetes, IHD, HT and sleep apnoea. Some years ago, an Arthritis Research Campaign Report 10 stated that joint surgery is less successful in obese patients because
Obese patients have a significantly higher risk of a range of short-term complications during and immediately after surgery (eg longer operations, excess blood loss requiring transfusions, DVT, wound complications including infection).
The heavier the patient, the less likely it is that surgery will bring about an improvement in symptoms (eg they are less likely to regain normal functioning or reduction in pain and stiffness)
The implant is likely to fail more quickly, requiring further surgery (eg within 7 years, obese patients are more than 10 times as likely to have an implant failure);
People who have joint replacement surgery because of obesity-related osteoarthritis are more likely to gain weight post-operatively (despite the new opportunity to lose weight through exercise following reduction in pain levels)
It also concluded that "Weight loss and exercise combined have been shown to achieve the same level of symptom relief as joint replacement surgery". A study of obese patients with knee osteoarthritis found that those who dropped their weight by 10% after a combination of diet and exercise reported less pain, better knee function, improved mobility and enhanced quality of life11.A recent extensive literature review advises assessment of "timely weight loss as a part of conservative care"12. It confirms in detail the increased risk of many perioperative and postoperative complications associated with obesity (as well as increased costs and length of stay), such as wound healing/infections; respiratory problems; thromboembolic disease; dislocation; need for revision surgery; component malposition; and prosthesis loosening.