The procedure
The worn surfaces of the femur, tibia and (where required) the patella are removed and replaced with a metal-and-plastic implant — a metal femoral component, a metal tibial baseplate and a highly cross-linked polyethylene bearing surface between them. The operation typically takes 90 minutes under spinal or general anaesthesia.
Computer navigation
Mr Gormack uses computer navigation as standard for knee replacement. Infrared trackers are attached to the bones, and the navigation system measures alignment and bone cuts in real time. This improves the accuracy of the cuts and the alignment of the implant — both correlated with long-term outcomes.
Robotic knee replacement
Robotic-assisted knee replacement is available for suitable patients. The surgeon plans the cuts on a 3D model of the patient's knee, and a robotic arm provides precise haptic guidance during the cuts. Robotic technology is complementary to computer navigation and may improve precision further in selected cases.
Implants
The femoral component is typically a cobalt-chrome alloy. The tibial baseplate is metal, with a highly cross-linked polyethylene insert above it that forms the bearing surface. Most implants are cemented in place with PMMA bone cement; cementless implants are used in selected younger patients.
Preparing for surgery
- Optimise general health — diabetes, weight, smoking and any active infections.
- Complete the pre-admission paperwork at least one week beforehand.
- Arrange help at home for the first week or two after discharge.
Hospital stay and recovery
- Standing within hours of surgery — often the same day.
- Hospital stay of 2–3 nights for most patients.
- Crutches for 2–4 weeks, then gradual return to unaided walking.
- Full functional recovery takes around 6 months, with ongoing improvement up to a year.
Risks
As with any major surgery, risks include infection, deep vein thrombosis, stiffness, persistent pain, periprosthetic fracture, nerve or vessel injury, leg length differences and very rarely cardiac complications. These are reviewed in depth at your consultation.
Activities
Most patients return to walking, cycling, swimming, golf and gentle gym work. Higher-impact running and twisting sports are usually discouraged to protect the implant. Kneeling is often uncomfortable for some time but typically improves.
Implant longevity
Modern total knee replacements are extremely durable, with the majority lasting well over 15–20 years. Computer navigation contributes to that longevity by improving the accuracy of component alignment.