A Robotic Knee Replacement is a high tech way to replace a worn out and arthritic knee. The word robotic however can be deceptive as it is the surgeon that performs the surgery and uses the robot as a tool or an aid to do this. Robotic arm assisted knee replacement would be more accurate however it doesn’t sound as catchy. Whether or not a robotic knee replacement is better or not is up for debate, I personally think that the leading robotic system, the Stryker MAKO system adds a significant amount to my surgical ability, I use the robot to perform a specific part of the operation in keeping with my surgical philosophy. I have had colleagues that dismiss robotic surgery as a fad, however these colleagues have unanimously been surgeons who have not been experienced or trained in using the system. I think it is worth talking about what a robot can and cannot do before talking about whether it is better than a traditional or manual knee replacement.
What a robot can and cannot do
A Robot cannot talk to a patient, decide when to operate, position a patient for surgery, cut the skin, carefully expose the knee joint, control bleeding along the way, safely close the knee joint and skin at the end of the operation, and support a patient post operatively. A robot can accurately cut and prepare the bone to accept the knee replacement in-keeping with the surgeons surgical plan. So really the robot replaces only a small part of the operation that the surgeon would normally perform using traditional techniques.
All steps of a knee replacement need to be performed well to get the best outcome. It is possible to use robotic assistance and perform a high quality or a low quality knee replacement, and it is equally possible to do the same with a manual knee replacement.
Are standard knee replacements good enough?
The largest studies show satisfaction rates of total knee replacement of around 80%, this means that 2 in 10 people may not be fully satisfied with their knee replacement, this may mean stiffness, clicking and clunking, or instability or another reason. This is the status quo. To continue matching these surgical outcomes no new techniques such as robotic surgery are required.
I believe that robotic knee replacement, in combination with modern alignment philosophies, can increase satisfaction levels and lead to more consistent and reliable outcomes.
Surgical philosophy makes a difference
There are several philosophies in performing a knee replacement, these generally relate to the alignment of the implants. The ‘historic’ gold standard alignment places the joint replacement in an average position that fits well with some but not most patients.
The alignment I perform a combination of kinematic alignment (which means placing implants closer to a patients normal anatomy), and functional alignment (which means respecting the tension in the ligaments around the knee). I have found these techniques mean I have less problems with stiffness and instability, and of the clicking and clunking that knee replacements are associated with.
Not all robots are the same, advantages of the Stryker MAKO system
The robotic system I use called the Stryker MAKO system has two specific advantages that fit with my personal approach to knee replacements. The advantages are specific to me, and this specific robotic system, these may not apply to other surgeons or robotic systems.
The first is the pre-operative planning, and intraoperative adjustment. When Performing a Stryker MAKO knee replacement a patient has a high resolution CT scan pre operatively, this is fairly unique in comparison to other systems. With this scan I can accurately size implants, and plan the alignment of these in 3 dimensions to fit a patients normal anatomy. This is not possible from just Xrays.
In addition to this accurate planning, I can use the Stryker MAKO system to measure ligament tensions intraoperatively, and then adjust my implant positioning accordingly. This means I generally do not need to release the ligaments around the knee to make the implant fit which is a common technique in other alignment philosophies. I believe that extensive release of the ligaments around the knee is a cause of pain and swelling post operatively, and may affect longer term stability.
This planning therefore allows me to align the implant with respect to both a patients bony anatomy, and also there ligament tension which fits with my surgical philosophy before I performed robotic knee replacements.
The second advantage is using the MAKO robotic arm to cut the bone according to my plan, The Robotic arm (which I control) can do this more accurately than I can without using robotic assistance, and generally is accurate to 0.5mm or less. This is really the execution of the plan, and if the plan is correct and the cuts are accurate, then the outcome will be a well balanced knee replacement.
Final thoughts
Whether a robotic knee replacement is better than a manual knee replacement is a difficult question to answer. Research has shown good evidence how the system is more accurate, and there are currently large studies comparing the two techniques. To me the research is difficult to interpret, as the largest studies compare all surgeons, using different surgical philosophies, with different robotic systems.
In my hands, using the Robotic system I have been trained to use, I believe a robotic knee replacement is a better operation.
Get specialist help today
with hip arthritis
Mr Samir Ali Salih
I am a consultant hip and knee surgeon specialising in joint replacements for arthritis using the Stryker MAKO robotic system
This article was written with human intelligence