Osteoarthritis of the knee presents with joint pain, deformity, stiffness, a reduced range of movement and sometimes giving way. The pain may be sharp and brought on by particular movements (flexing, extending or turning on the knee), or may present as a dull ache occurring at rest especially after periods of activity or during the night. Stiffness tends to be worse after being immobile, and usually improves for a while with use.
Examination may reveal fixed deformity, swelling, tenderness and loss of normal range of movement. Osteoarthritis is not associated with systemic illness.
Osteoarthritis is common and its prevalence increases with age. In most patients with radiological changes, symptoms are not sufficiently troublesome to prompt a general practice consultation. In some patients symptoms may be intermittent but in others they may be relentless and debilitating. The underlying joint changes of osteoarthritis are generally irreversible and management aims to relieve symptoms and reduce disability.
Initial management strategies for patients with osteoarthritis of the knee include assurance and patient education, weight reduction in patients who are obese, walking aids, help with patient-specific exercise programmes, and assessment and advice on cushion-soled footwear.
Drug treatment typically includes courses of simple analgesic and non-steroidal antiinflammatory drugs. Aspiration and intra-articular steroid injections are undertaken by some GPs.
Patient must have had a knee x-ray, views AP weight bearing, lateral and skyline, and a copy of the report should be enclosed with any subsequent referral letter.
These are in a position to:
- Confirm or establish the diagnosis
- Provide management advice coupled with physical therapies
- Assess the need for, and undertake, joint surgery and rehabilitation
- Undertake intra-articular injections of drugs
The majority of the management of patients with osteoarthritis of the knee is undertaken in primary care. However, referral to a specialist service is advised if:
* There is evidence of infection in the joint
* There is evidence of acute inflammation caused by, for example, haemarthrosis, gout or pseudo-gout
* Giving way is a problem despite therapy
* Symptoms rapidly deteriorate and are causing severe disability
* The symptoms impair quality of life. Referral criteria should take into account the extent to which the condition is causing pain, disability, sleeplessness, loss of independence, inability to undertake normal activities, reduced functional capacity or psychiatric illness.
When not to refer
- Excessive weight. Surgery is almost certain to fail in the obese patient.
- Poor general medical condition. If the patient is unfit to have a general anaesthetic, then surgery is obviously precluded.
- General sepsis.
- Open ulcers on the leg, etc.
Aims and type of treatment
The aim of treatment is to reduce pain, correct deformity and restore function in the knee.
The most common procedures undertaken are:
- Arthroscopy, washout and debridement of the knee.
- Arthroplasty, either unicompartmental or total.
Advice to patients
- Arthroscopy, washout and debridement of the knee can temporarily improve symptoms but is not curative.
- Osteotomy will correct deformity and relieve pain. This will not be curative but may relieve symptoms for many years.
- Arthroplasty. An arthroplasty of the knee will not give a normal knee but will relieve pain and correct deformity. The range of movements anticipated is 90-100 degrees of flexion and full extension. There should be an 80-90% fifteen-year survival rate.
- Patients will be advised to have a dental check-up prior to surgery to exclude any chronic sepsis.
- Offer of attending Knee Class – for education / information
- Patients will be seen in a pre-admission clinic 2-4 weeks prior to admission for assessment of their general health and routine investigations to be undertaken.
- The patient will be admitted on the evening before or day of surgery.
- The patient will be an Inpatient for approximately 4-7 days or until 90 degrees of flexion of the knee is obtained. Discharge dates will depend on their social circumstances and a COPE assessment.
- The patient should be independent on sticks, with 90 degrees of flexion of the knee prior to discharge.
- The patient will be followed up in Outpatients for one year.
The patient should be warned of the following risk:
- Anaesthetic risks.
- Deep vein thrombosis.
- Delayed wound healing.
- Infection. Infection in a total joint can be a potential disaster and may mean removal of the prosthesis and possible arthrodesis of the knee or amputation.
- With the present knee replacements, an excellent or good result should be obtained in 90% of patients.