So robotic-assisted knee surgery involves the use of a specialised surgical robot to
try and increase or improve the accuracy of the surgery. When we do conventional knee
replacements, we rely on measuring things with rulers and measuring angles with protractors
to try and put the knee in the best possible position. We can be reasonably accurate with
this, but some may be not be perfectly accurate. The use of the robot allows us to be much,
much, more accurate and to position the knee replacement in the perfect position.
The real importance of this is that despite our very best efforts, only about 80% of patients
who’ve had a knee replacement are delighted with their new knee and we think that part
of this is due to the complicated shape of the knee but also very definitely a part of
it is in terms of getting the new knee implanted in the patient in exactly the right position.
And this is where the use of a surgical robot is really exciting in terms of trying to get
a perfect result every time.
We use the robot for carrying out either partial
knee replacements or total knee replacements. This is for patients who’ve got severe arthritis
in their knees so they’ve got pain and stiffness all the time and the knee is essentially worn
out so they need a new knee. If only part of the knee is worn out, then we are only
need to replace part of the knee. And we can use the surgical robot in order to implant
a partial knee replacement in the absolute perfect position to make somebody’s knee
feel really natural and normal after the surgery so they can get back to a good quality of
life and enjoying all of the things that they want to.
We can also use it for a total knee replacement. This is where all of the knee is replaced
rather than just one damaged part and it’s for patients whose disease is somewhat more
severe and more than one part of the knee is affected. Unfortunately, even the best total
knee replacements aren’t as good as partial knee replacements, but again by using robotic
surgery and getting the new knee in exactly the right position, we can improve the outcomes
and give people a better end result.
The whole process for robotic-assisted knee
surgery will begin with somebody coming to me to describe the problems with their knee
and I’ll assess their knee, probably take some x-rays to make the diagnosis and see
which parts of the knee are damaged, and then make a decision as to what intervention is
required. If that intervention is a knee replacement of some sort, then we’ll have a discussion
as to whether we do conventional surgery or robotic-assisted knee surgery.
If we choose to go down the route of robotic-assisted knee surgery, then the next step is to get
a pre-operative CT scan of the knee. This gives us enough information to make a three dimensional computer
model of the knee so we know the exact shape of the patient’s knee. We then upload that
model to the robot. We use that during the surgical procedure.
On the day of the surgery, the robot will already have all of the information about
the shape of the patient’s knee. We already have the good idea of the size of the implant
that’s required and the exact position of the implant.
During the surgery itself, we attach some special markers on to the patient’s leg
and we define different regions of the patient’s body so that the robot now knows the shape
of the knee, but also knows where the knee is within the operating theatre. This then
allows me to start using the robot to make the surgical resections of bone or trimming
away the diseased parts of bone during the operation.
Once we’ve told the robot where the knee is and the robot knows the shape of the knee,
I can start the surgery. The surgery for a conventional knee replacement involves using
a saw to cut off surfaces of bone but with the robot, we use a rotary burr to take off
the bare minimum of bone and to shape the patient’s bone perfectly for the implant.
We take measurements before the surgery, during the surgery, and after the surgery with the
robot to ensure that we get an absolute perfect result according to the plan. It gives me
real confidence because the robot allows me to make sure that everything is going perfectly
all the way through the procedure.
The benefits of using the surgical robot for
knee replacement surgery really centre around improving patient outcomes. We know that with
conventional knee surgery, the satisfaction rates are about 80-90% and we’d like to
drive those up much higher. Part of the problem with dissatisfaction is that the knee is a
complicated joint with complicated shapes but newer implant designs are beginning to
mimic these very, very well. Another problem is getting the new knee perfectly
implanted into the patient in exactly the right position. And this is where robotic
knee surgery comes into its own. By doing the scans beforehand and understanding the
shape of the patient’s knee, we can then make calculations in the model for implanting
the new knee and measure both before, during, and after the surgery to make sure we’ve
got everything right. Essentially, what the robot does is exclude human error from the
procedure so that we can get a perfect result every time and therefore, hopefully driving
up the satisfaction rates and making patient’s knees feel a whole lot better.