Signs you may need a knee replacement

Most people arrive at a knee clinic having already been told by someone that they need a replacement. Often they do not, at least not yet. What decides it is less the X-ray than what the knee stops you doing.

What the pain is telling you

• Pain at night, or pain that wakes you, is treated as a more serious sign than pain during activity.
• Pain at rest, sitting still, suggests the joint is irritable rather than simply worn.
• Difficulty on stairs, particularly going down, is a common early sign that the joint surface is involved.
• Shrinking distance. How far you can walk before you have to stop is one of the most useful things you can tell a surgeon.

Why the scan is not the whole answer

• Two people can have almost identical X-rays and be living completely different lives. One walks two kilometres without thinking about it, the other cannot reach the end of the street.
• A grade on a report does not decide surgery on its own. Many knees with visible wear are managed for years without an operation, and that is the right outcome when it is achievable.

What gets assessed at the consultation

• A standing X-ray of both knees, because alignment only shows properly under load.
• How the knee moves, how stable it is, and whether the problem is coming from the knee at all. Hip problems frequently present as knee pain.
• What has already been tried: physiotherapy, weight, activity changes, injections.
• What you need the knee to do. A farmer, a teacher and a retired accountant have different thresholds, and the answer should reflect that.

When it usually is time

• When pain is present at rest and at night, when walking distance has collapsed, and when the non-surgical options have genuinely been tried rather than merely mentioned.
• Even then it is a decision made with you, not for you.