Do I Need a Knee Replacement Yet?

Patients usually expect the decision to hinge on their X-ray. It does not. I have operated on knees that looked moderate on film and declined to operate on knees that looked terrible, because the X-ray describes the joint while the decision is about the person.

The question I am actually answering is narrower than “is the knee worn out?” It is: has the knee taken away enough of your life that replacing it is worth the operation, the recovery and the risk? Nobody but you can supply half of that answer.

Taken together rather than individually, these point clearly towards replacement:

• Night pain that wakes you. Arthritis that hurts only on exertion is being managed. Arthritis that hurts at rest and interrupts sleep has usually moved past that.
• Walking distance has collapsed. Not “it aches after two kilometres” but “I stop twice between the building gate and the main road.”
• Bone-on-bone contact on a standing X-ray — and it must be standing. A knee X-ray taken lying down understates joint space loss and is close to useless for this decision.
• Visible deformity that is progressing. A leg that is bowing more each year is not stable; it is deteriorating, and the surgery gets larger the longer it runs.
• Injections and physiotherapy have stopped helping — or the relief now lasts weeks where it used to last months.
• Painkillers have become routine. Daily anti-inflammatories carry real risks to the stomach and kidneys. Taking them indefinitely to avoid an operation is not the safer path people assume it is.

These are the situations in which I actively advise against operating now, even when the patient has arrived expecting to schedule surgery:

• The pain is real but the function is intact. If you are still doing what you want to do, a replacement is trading a working knee for a better one — and the new one has a finite lifespan.
• Nothing has been tried properly. A course of physiotherapy actually completed, not abandoned in week two. Weight loss if it applies. A trial of injection. Many knees improve enough that the question moves several years down the road.
• The pain may not be coming from the knee. Hip arthritis and lumbar spine problems both refer pain to the knee, and a replaced knee does nothing for either. This is missed more often than it should be.
• You are young and the arthritis is limited to one compartment. A partial knee replacement, or in selected patients an osteotomy, may serve you far better than a total replacement at forty-five.
• Diabetes is poorly controlled, or there is an active infection anywhere — dental, skin, urinary. These raise the risk of the one complication you most want to avoid. Fix them first; the knee will wait.
• You are not convinced. Recovery requires work in the first six weeks. Patients who were pushed into surgery do measurably worse than patients who chose it.

You are entitled to interrogate a surgical recommendation, and a good surgeon will not mind.

• “What happens if I wait a year?” There should be a specific answer — either “nothing much, we review it” or a concrete reason why delay costs you something.
• “What have we not tried yet?” If the list is not empty, ask why we are skipping it.
• “Is my X-ray standing or lying?” If it was taken lying down, the assessment is incomplete.
• “Could this pain be from my hip or back?” A surgeon who has examined those will answer immediately.
• “What would you advise if this were your parent?” It reliably produces a more candid answer than any other question.

And if the recommendation is surgery and you remain unsure, take a second opinion. No competent surgeon is offended by this. A knee that genuinely needs replacing will still need replacing in three weeks.