This is essentially a “mini GPS system” which lets a surgeon “track”, analyse and monitor on a screen, the instrumentation used during a knee replacement.
This system produces a 3-d model of a patient’s knee on a computer screen using infra-red technology (probes attached to the femur and tibia bones). This enables a surgeon to “align the components properly” after doing the bone preparation using the navigation.

No. An experienced surgeon who specializes in knee surgery is usually well skilled to recognize proper sizing and alignment of components and does not need navigation for accuracy and reproducibility.

Navigation knee replacements are useful especially when there are bone deformities above or below the knee due to previous trauma/fractures or congenital problems with mal-alignment.

There are many studies that have tried to compare navigation vs non-navigation knee replacements in standard populations. The general consensus is that there is not much difference between them, especially in the hands of an experienced surgeon when comparing alignment and knee function.

No. The actual knee components are not navigated. Only the “bone cuts” are navigated so surgeons assume, as they place the components, it will “slot” into the cuts that are made.

This is a very important question. We are still waiting on answers to this. There is still a small possibility of minor errors if the bone cuts aren’t made properly that components may be mis-placed, but surgeons usually make sure the components “look” in good alignment and xrays after surgery will prove this.