Treatment decision6 min read
When is knee replacement needed? The decision criteria
Knee replacement markedly improves quality of life in advanced osteoarthritis. There are common misunderstandings about its timing and indication, however; the decision does not rest on a single imaging finding.
The decision criteria
Pain persisting at rest at night and disturbing sleep is among the strongest indicators, signalling the picture has reached the limits of conservative treatment.
Inability to walk short distances or climb stairs, and marked limitation of daily tasks, are grounds for surgical assessment.
There must be no progress despite appropriate, sufficiently prolonged conservative treatment. A surgical decision made without trying an exercise programme is premature.
Timing
Replacement done too early raises the likelihood of revision surgery over a lifetime. Implants have a limited lifespan and a second operation is likely in a young patient.
Leaving it too late also causes problems. A patient immobile for long develops muscle loss and joint stiffness, which adversely affects the outcome.
The decision sits between these extremes, weighing age, activity expectations and current limitation together.
Before and after surgery
Pre-operative muscle strength directly affects the outcome. The exercise programme therefore continues, and is often intensified, in patients scheduled for surgery.
Post-operative rehabilitation is essential. Surgery replaces the joint but does not restore muscle strength, range of motion or gait.
Expectations should be realistic. A replacement markedly reduces pain and improves function, but it does not feel exactly like a natural knee and some movements may stay limited.
Key points
- The decision rests on quality of life, not X-ray stage.
- Pain persisting at rest at night is among the strongest indicators.
- Replacement too early raises the likelihood of revision surgery.
- Pre-operative strength directly affects the outcome.
- A replacement does not feel exactly like a natural knee.
Frequently asked questions
How long does a replacement last?
A large proportion of implants function for fifteen to twenty years or more today. Lifespan varies with activity level, weight and surgical technique.
Is partial replacement an option?
Where arthritis affects only one compartment, partial replacement can be suitable. It is a smaller operation with faster recovery; suitability depends on assessment.
How soon will I walk after surgery?
Most patients stand with support on the day of surgery or the next. Independent walking usually takes a few weeks, with full recovery in three to six months.
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This content is for information only and does not replace medical diagnosis or treatment. Response to treatment varies between individuals. Please consult a healthcare professional about your symptoms.