| What We Treat
Knee Replacement
Facing a knee replacement, or working through the recovery? What happens in the weeks either side of surgery shapes the result more than most people are told — and range of movement is the part with a deadline.
Overview
What Is a Knee Replacement?
A total knee replacement resurfaces the worn ends of the thigh and shin bones with metal components separated by a plastic bearing. It is one of the most successful operations in orthopaedics, with high satisfaction rates and implants that commonly last twenty years or more. It is not a quick fix, though: the first six weeks are demanding, full recovery takes a year, and how hard you work on movement early on has a lasting effect.
Prehabilitation
Go in as strong as possible
- Quadriceps strength before surgery is one of the best predictors of function afterwards
- Progressive strengthening for the quadriceps, hamstrings and hips
- Practising the exercises you’ll be doing after the operation, so they’re familiar
- Practical preparation — home set-up, equipment, and arranging support
Tap through the phases. The first six weeks set the ceiling for your range of movement.
Symptoms
What to Expect Afterwards
Knowing what’s normal saves a great deal of unnecessary worry in the first months:
Swelling for Months
Swelling that fluctuates with activity is normal for six to twelve months, not just weeks.
A Warm Knee
The knee feeling noticeably warmer than the other one is expected for several months.
Night Discomfort
Disturbed sleep is very common in the first six to eight weeks and improves steadily.
Clicking or Clunking
Noises from the implant are common, usually painless, and not a sign of a problem.
Numbness Beside the Scar
A patch of numbness on the outer side of the scar is normal and usually permanent.
Kneeling Difficulty
Many people never find kneeling fully comfortable, which is worth knowing in advance.
Causes & Risk Factors
What Influences the Outcome
Several factors have a measurable effect on how well a replacement turns out, and some are within your control.
Pre-Operative Strength
Quadriceps strength before surgery is one of the strongest predictors of function a year later.
Early Range of Movement
Movement gained in the first six weeks is far easier to keep than movement chased later.
Adherence to Rehabilitation
Consistency with the strengthening programme is the single biggest modifiable factor.
Expectations
People with realistic, well-informed expectations report substantially higher satisfaction, independent of the actual result.
General Health
Diabetes, smoking and body weight all influence wound healing, infection risk and recovery speed.
How We Can Help You
Treatment & Management
Physiotherapy runs either side of the operation. Before, it builds the strength you’ll draw on; afterwards, it protects your range and rebuilds what surgery costs you.
What the evidence says
Total knee replacement produces large improvements in pain and function for most people, though around one in five report some ongoing dissatisfaction — most often related to expectations, residual stiffness or persistent quadriceps weakness rather than to a technical problem with the implant.
Quadriceps strength commonly remains below the other leg for a year or more after surgery unless specifically trained. Progressive resistance exercise after knee replacement has good supporting evidence for improving function beyond usual care.
When to Seek Help
Red Flags — Don’t Ignore These
Most recovery is uneventful. These features need prompt medical attention:
⚠ Contact your surgical team or seek urgent care if you notice:
- Calf pain, swelling, warmth or redness (possible clot — seek same-day assessment)
- Breathlessness or chest pain (possible pulmonary embolism — call 999)
- Increasing redness, heat, wound discharge, or fever (possible infection — contact your surgical team urgently)
- A sudden increase in pain, or the knee giving way, particularly after a fall
- Rapidly worsening stiffness with range of movement going backwards
Infection after joint replacement needs urgent attention, and pain that is worsening rather than improving always warrants contacting your surgical team rather than waiting.
Common Questions
Frequently Asked Questions
How much bend should I expect?
Most people achieve between 110 and 120 degrees, which is enough for stairs, cycling and getting out of a car comfortably. Around 90 degrees is generally considered the functional minimum. The range gained in the first six weeks is the strongest predictor of the final result.
How long until I feel normal?
Longer than most people are told. Walking comfortably usually comes within six to twelve weeks, but genuine improvement continues for a full twelve months and sometimes into the second year. Expecting to be finished at three months is a common source of disappointment.
Can I kneel on it?
Some people can, many find it uncomfortable, and a proportion never kneel comfortably again. It isn’t harmful to try, and it doesn’t damage the implant — it’s simply that the tissue over the front of the knee often stays sensitive.
What activities can I go back to?
Walking, cycling, swimming, golf, bowls, doubles tennis and gardening are all generally encouraged. Running and high-impact sport are usually discouraged, mainly to reduce wear on the bearing rather than because of any immediate risk.
The Work Either Side of Surgery
Prehabilitation before, and a structured programme afterwards that protects your range and rebuilds your strength properly.
Book Your Initial AssessmentThis page is for general information only and isn’t a substitute for individual medical advice. If you’re experiencing any of the warning signs above, contact your GP or seek emergency medical care as appropriate.