Robotic Joint Replacement
Robotic joint replacement has only recently been available in Australia with the first procedures performed in 2016.
At this stage it is available for Total Hip Replacement and Partial Knee Replacement
Mr Shane Blackmore is one of the first surgeons in Victoria trained and accredited with performing Robotic Joint Surgery. He took part in Robotic Joint Replacements while on fellowship in New York and the returned to the USA last year to observe a number of experts in the field in various centres around the USA. In order to become accredited in Australia to use this technology you must complete specific training courses. Shane was the first Vicrotiran surgeon to complete both of these for the two types of joint replacement currently available – total hip and partial knee.
Joint replacements have been a successful treatment for arthritis for a number of decades. What we have learnt is that a number of factors are important to have a successful joint replacement that will last. These factors include the material it is made of as well as how it ‘sticks’ to the bone. As a surgeon various orthopaedic companies have made advances in these areas over the decades. However no matter have much the material have improved what is still the most important factor to prevent your joint replacement displacing, wearing out or even loosening is the position of the various components which is all determined by the surgeon.
Despite years of experience countless studies have shown we are not as good as we think we are in placement of joint prothesis or the cuts in the bone we make to seat them.
This is a robot with a computer guidance system has shown to increase our precision in cutting the bone for your joint replacement as well as position the joint replacement components in the best position.
This starts with a CT scan of the joint needing to be replaced. In the past we have used X-rays which can be in-accurate in their sizes to template or best guess what size implants and position to they need to be put in. With the use of a CT the exact size and position of the components is pre calculated with a precise model. Here are some screenshots of total hip being calculated.
During the operation specific points are marked out so the robot and computer can match these to those planned on the CT. Before any bone is cut or any implants are inserted the robot and computer provide a specific plan of what will work best in terms of component size and position for this patient.
The surgeon check this the be certain the component are going to be place in a precise position.
In traditional joint replacements thesis often done when bone starts to get cut which if incorrect can be difficult to undo. With a robotic joint replacement this can be done before any irreversible bone cuts are made.
In the diagram on the left the computer is simulating the balance the joint with the pre-planked component position. Essentially all lines on the bar graph should be equal. With a a couple adjustments on the simulated component positions this is corrected before the robot cuts the bone for the replacement.
This is what makes robotic joint replacement a powerful and precise instrument in joint replacement surgery.
Now that the simulated joint replacement is in an excellent position with appropriate balancing the robot can but the bone with great precision. The robot with is computer guidance cuts bone with less than 1mm of error which is extremely precise. This is often the easiest part of the operation as the robot is computer guided as per the plan.
Here is an example of the robots precision in placing the cup part of a total hip replacement. This surgeon compared his first 100 hip replacements aiming for the target zone which he hit 31% of the time – note his dislocation rate and fracturing of the liner. The last 100 manual (middle box) when he was a lot more experienced saw an improvement in hitting the target zone to 45% of the time.
It wasn’t until he switched to robotic surgery and even through it was his first 100 robot operations when he had less experience his accuracy improved to 76% but importantly no fractures or dislocation .
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