Osteoarthritis of the Knee

Symptoms and Signs

Commonly >50 years (previous history of knee surgery reduces age range)
Pain (particularly on moving, weight bearing or at the end of the day)
Reduced range of flexion/extension with stiffness (especially after rest, or at start of day )
Crepitus
Hard swelling (caused by osteophytes) or Soft swelling (synovial thickening/effusion/bursitis)
Reduced walking distance/ Limp/ Use of walking aid/ ADL

Exclude hip/spine pathology and inflammatory arthritis
Analgesics/NSAIDs
A current flare-up of arthritis can be temporary and often improves with time to a more manageable level. Where analgesics and/or NSAIDs are ineffective or contra-indicated, an intra-articular corticosteroid injection which can be administered in primary care by a GP, FCP or MSK physiotherapist. Up to 3 injections spaced a few months apart over a year is reasonable
Walking aid, advise patient to stay as active as possible and to continue normal daily activities,
Weight loss if appropriate, (1:8 failure rate for surgery with BMI over 35)
Physiotherapy assessment/treatment
Unfortunately, there are no good surgical solutions for earlier stages of osteoarthritis. Once there is established arthritis on x-rays, knee arthroscopy is highly unlikely to give lasting benefit and can make patients worse off.

Weight bearing XR to confirm diagnosis or if meaningful change in management would be facilitated

Significant persistent severe constant pain/disabling symptoms/decrease in function, refractory to conservative management
Significant end stage OA (at least moderate) changes on recent XR (Tri-compartment) that is clinically relevant NB: imaging changes correlate poorly with clinical findings and pain - changes on their own should not trigger referral for a surgical opinion.
Severe joint arthritis from inflammatory arthritis
Problems with previous knee replacement
Appropriate BMI: Whilst we do not have an exact cut-off for BMI, being substantially overweight increases the risk of component malalignment, chronic pain, early failure and catastrophic extensor mechanism failure as well as increasing the risk of medical complications. Obesity is a correctable risk factor for surgery and every attempt should be made to reduce the risks of surgery with weight reduction. Ideally, patients should be encouraged to try to reduce their BMI to less than 30 i.e. less than class 1 obese. A BMI of >35 (Class 2 obesity and over) seems a reasonable absolute cut-off point. Referral to Tayside weight management service may be appropriate for those patients trying to lose weight.
Significant sleep disturbance
Previous attempt at weight reduction and failed rehabilitation
Is a surgical candidate (no uncontrolled medical co-morbidities/major contraindications) and patient is willing to have major surgery
All of the above despite appropriate analgesics

There are implications of undergoing knee replacement at a younger age (less than 60) with younger patients at higher risk of dissatisfaction, a 9-fold higher risk of early failure (according to the National Joint Registry) and a higher risk of requiring much more complex revision (re-do) surgery and disability later in life.
Younger patients with knee arthritis should have severe pain refractory to conservative measures with severe x-ray changes of arthritis to be considered for surgery.
Younger patients who have physically demanding jobs or hobbies risk early failure of a knee replacement from mechanical overload and should seek to change their workload or lifestyle rather than undergo knee replacement.

SCI Gateway/Orthopaedics/Knee
If the patient is under the care of NHS Physiotherapy, investigations and onward referral to knee service, if appropriate, will be organised by Physiotherapy service without the need for further GP intervention.

Information to include in referral: