Knee Replacement Surgery: What to Expect on the NHS

📅 Last reviewed: February 2026 · Sources: NHS.uk, NICE
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NHS Knee Replacement Surgery: Complete Patient Guide

Knee replacement (arthroplasty) is performed over 90,000 times a year on the NHS. This guide covers who needs the procedure, what to expect during surgery, recovery timelines, and risks — helping you make an informed decision with your NHS consultant.

⚡ Key Facts
  • Operation time: 1–2 hours
  • Anaesthetic: General or spinal anaesthetic
  • Hospital stay: 3–5 days typically
  • Return to light activity: 6 weeks
  • Full recovery: 6 months to 1 year
  • Implant lifespan: 15–20+ years

What is Knee Replacement Surgery?

Knee replacement surgery involves removing damaged bone and cartilage from the knee joint and replacing the surfaces with metal and plastic components that replicate the smooth, natural gliding of a healthy knee. The procedure is primarily performed to relieve pain caused by severe osteoarthritis.

There are two main types: total knee replacement (TKR), where the entire knee joint surface is replaced, and partial (unicompartmental) knee replacement, where only one side of the knee is replaced. Your consultant will advise which is more suitable based on which part of your knee is damaged.

Who Qualifies for an NHS Knee Replacement?

Your GP may refer you for knee replacement if you have severe, persistent knee pain — particularly from osteoarthritis — that significantly affects your mobility and daily life, and has not been adequately controlled with physiotherapy, pain relief, steroid injections, or other non-surgical treatments.

💡 NHS Funding Criteria

Some NHS Clinical Commissioning Groups (CCGs) apply additional criteria — such as a minimum BMI threshold or requirements to complete physiotherapy first. Ask your GP what applies in your local area.

Recovery After Knee Replacement

  • Day 1–2: Physiotherapy begins in hospital. Most patients can stand and take steps with support.
  • Week 1–6: Walking with crutches. Swelling and pain is managed with medication and elevation.
  • Month 1–3: Returning to light activities, driving (typically after 6 weeks, once you can do an emergency stop). Continue physiotherapy exercises daily.
  • Month 3–6: Most patients return to everyday activities. Swimming often permitted from 6–8 weeks.
  • Year 1: Progressive improvement in strength and mobility with ongoing exercises.

Risks and Complications

Note: All surgery carries risk. Your consultant will discuss risks and benefits in full before you consent. Risks of knee replacement include blood clots, infection (1–2%), stiffness, nerve damage, and implant loosening over time requiring revision surgery.

Medical Disclaimer: This page provides general information only. It is not a substitute for professional medical advice. Always consult your NHS GP or consultant about your individual circumstances.