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Unicomartmental Knee Replacement

Why we do UKR

Arthritis only in one part of the knee (medial side)

The rest of the knee (ligaments + other compartments) is still healthy

Younger patients benefit from keeping as much of their natural knee as possible

It delays the need for a full knee replacement

Benefits

Smaller operation / less trauma

  • Smaller cut (incision)
  • Less bone removed
  • Less damage to muscles and tissues

Faster recovery

  • Get moving quicker
  • Often shorter hospital stay
  • Back to normal activities sooner

Less pain

  • Less surgical trauma → less pain after surgery

Feels more “natural”

  • Knee feels more like your own
  • Better movement and function than total knee in many cases

Less blood loss

  • Smaller operation → less bleeding

Safer early on

Lower risk of serious complications and even lower early death rates compared to total knee replacement

Risks & complications

General surgical risks

  • Infection
  • Blood clots (DVT/PE)
  • Bleeding

Specific to UKR

  • Arthritis can develop in the rest of the knee later
  • Implant can loosen or wear out
  • Bearing dislocation (rare, but known issue in some designs ~2–3%)
  • Ongoing pain or need for further surgery

Revision risk

What the UK National Joint Registry (NJR) + evidence shows:

  • Around ~6–11% revision at 10 years (varies by implant and technique)
  • Some studies show:
    • ~7–10% at 10 years
  • Best-performing implants:
    • About ~6% at 10 years

👉 Rough patient-friendly summary:

  • About 90–94% still working at 10 years

Compared to total knee replacement (important context)

  • UKR has higher revision rates than total knee
  • But:
    • Lower complications early on
    • Better function and recovery

Younger patients (key point)

  • Younger age = higher chance of needing revision
  • Lifetime revision risk can be:
    • ~25% if done around age 55
    • “This is a smaller, less invasive operation that replaces only the worn part of your knee.
    • You recover faster, it feels more natural, and has fewer early risks.
    • But because you’re younger, there’s a higher chance you may need another operation later.”