Understanding Partial Knee Replacement
When arthritis affects only one compartment of the knee, a partial (unicompartmental) replacement resurfaces just that worn area, leaving the healthy cartilage and both cruciate ligaments untouched.
Because it is a smaller operation that preserves more of your natural knee, many patients enjoy a quicker recovery, a more natural-feeling knee and a smaller scar — provided the arthritis is genuinely confined to one compartment.
Key benefits
- Preserves healthy cartilage and ligaments
- Often a quicker recovery than total replacement
- A more natural-feeling knee and smaller incision
When Partial Knee Replacement is recommended
How the procedure is performed
Confirmation
The single affected compartment is confirmed as suitable, with healthy remaining cartilage and ligaments.
Resurfacing
Only the damaged surface is removed and resurfaced with a compact implant.
Preservation
The healthy cartilage and both cruciate ligaments are preserved for a natural-feeling knee.
Early mobilisation
A smaller incision means recovery and walking often begin quickly.
Preparation & prerequisites
- A detailed clinical assessment and review of your scans (X-ray / MRI) to confirm the diagnosis and plan the surgery precisely.
- Routine pre-operative blood tests, an ECG if needed, and a fitness-for-anaesthesia check by the anaesthetist.
- Stopping blood-thinning medication (such as aspirin or clopidogrel) only if advised, and disclosing every medicine and supplement you take.
- Fasting for around 6 hours before surgery, and arranging a responsible adult to drive you home and stay with you the first night.
- Preparing your home for recovery — ice packs, loose clothing, and a clear path free of trip hazards.
What recovery looks like
Days 1–3
Early walking with support, often faster than after a total replacement.
Weeks 1–4
Movement and strength return quickly with physiotherapy.
Weeks 4–8
Daily activities resume comfortably.
How to recover well
- Follow the RICE principle early — rest, ice 15–20 minutes several times a day, gentle compression and elevation to control swelling.
- Take pain relief as prescribed rather than waiting for pain to build, and keep the wound clean and dry.
- Attend every physiotherapy session and do your home exercises — rehabilitation is as important as the surgery itself.
- Progress activity gradually and don't return to sport until you're formally cleared, to protect the repair.
- Watch for warning signs — spreading redness, fever, calf pain or increasing swelling — and call us if they appear.
Risks, safety & outcomes
In experienced hands this is a very safe procedure, and serious problems are uncommon. Every step is taken to minimise risk — but being fully informed is part of good care. Possible risks include:
- Arthritis can progress in the other compartments over time
- A small chance of needing conversion to a total replacement later
- The usual small surgical risks of joint replacement
Results & outlook
In well-selected patients, partial replacement gives excellent pain relief with a natural-feeling knee and a faster recovery, and can be revised to a total replacement in future if needed.
Frequently asked questions
It suits arthritis confined to one compartment with intact ligaments and good movement — confirmed on examination and imaging.