Learn more about Dr. Steve Nishiyama’s approach to revision knee arthroplasty using the CORI™ Surgical System. During this 11 minute case-based webinar, Dr. Nishiyama provides the surgical workflow for robotic-assisted rTKA and and narrates his surgical technique during a live procedure.
Hello, my name is Steve Nishiyama. I'm a adult reconstruction, hip and knee surgeon at the Desert Orthopedic Center in Las Vegas, Nevada. I have the privilege of presenting to you all today. Uh The first and only robotics platform indicated for the use of revision total knee arthroplasty. And that is the marriage between Smith and nephew's coy surgical system along with the legion RK revision total knee arthroplasty system. We present to you today, an 80 year old female that's otherwise quite healthy. Harr's had a worsening insidious onset of left knee pain for the last five years. She had her index primary toll in the arthroplasty performed at an outside institution in 2011 and is otherwise done quite well. Hover started developing substantial startup pain particularly in the area of her, a knee. Uh her preoperative infectious work up has otherwise been unremarkable. Here are her preoperative radiographs that do show evidence of uh likely aseptic loosening of her tibia component with Luc about the entirety of the proximal tibia and various collapse of her tibia component. The feral component appears to be well fixed. However, there are some Luc particularly along the uh post your Conal. Here is the workflow for the total knee arthroplasty surgical revision with the use of the core system, it's really critical to understand that the execution of a revision total knee with the core system is really an alteration of the surgical workflow of a primary total knee. However, it's really capitalizing on the unique technology. The coy system has to offer to really more efficiently and more precisely execute your revision total knees. As with most enabling technologies, we first establish the mechanical a accesses of both the tibia and the femur. And first, we are establishing the medial and lateral mao line. We then move on to the promo tibia and establish the tibia knee center and we do the same for the femur as well. We then have to provide the robot, the information of the hip center and via hip circumduction, we are able to calculate the root mean square, creating a cone to effectively define the the the femoral head center and give the mechanical access information to the robot. We then establish the overall alignment of the leg, then take it through a range of motion to establish the preoperative range of motion. One of the unique aspects of the coy surgical system is utilizing computer vision technology to create a virtual three dimensional map of the entirety of the joint surface. And you can see here we are acquiring the topographic information along the entirety of the distal femur to define the anatomy of the distal femur here. And you can see that we're creating quite a precise virtual representation of that. We then move on to using the special points feature to establish the implant and bone interface. And then also establish the trans epi condo or ax accesses by defining the both medial and lateral epis and then establishing the femoral rotation, we then move on to doing the same with the proximal tibia. And what it's doing is collecting this topographic information and cross referencing this and creating a virtual three dimensional representation of the anatomy along the proximal tibia. And I'm trying to give as much information to the robot here in order for the robot to have as accurate and precise information as possible. And generally speaking, in a revision setting, we certainly I think acquire more data than compared to a primary revision, excuse me, a primary tool. In e case we then move on as we did with the femur and using special points is establish the implant and bone interface to be used later. Another unique aspect of the core surgical system is the ability to define objectively the gaps throughout the entire arc of motion. Whereas some robotic systems only give you information at discrete points. And you can see here, I'm applying a very invious stress throughout the entire arc of motion and defining the gaps that are currently in place. We'll then move on to then planning the surgical case and you can see here not a tremendous amount of adjustment will be necessary. However, we adjust the femoral component ever so slightly. In order to create a well balanced knee, you then move on to removing the implants per your standard surgical technique. Fortunately, in this case, the tissue component was quite easy to remove. Then next, the very unique aspect of the core surgical system is to be able to visually assess the extent of bone loss in order to accurately plan for augments. And you can see here in the red, there's a substantial amount of bone loss relative to our surgical plan. Therefore, indicating likely the need for augments poster immediately, there will likely not need an augment as they were still remaining purple, blue and green. They're indicating remaining bone, we can then move on to objectively defining those that extent of bone loss and along the distal medial thermal condo. Here it appears it will likely necessitate at least a five millimeter augment and laterally, possibly a 10, possibly a 15. And this helps us prepare and plan for that moving forward. Then thirdly, you're able to actually utilize special points to actually map the bony defects that are currently in place. And on the next screen, you will see that we're able to actually visually define in a cross section of view, the extent of bone loss and plan for augments accordingly. Here we are first going to address the distal femur defects and as I said, prior distal media will necessitate a five millimeter augment. So therefore, we proximal the component five millimeters to account for that bony defect. And we are just focusing first here along the distal medial femur and utilizing the handheld precision robotic mill, we then focus our attention just along the distal medial femur to appropriately prepare the bone for that five millimeter augment. And what we are doing here is removing that color and trying to achieve a flat level surface which is indicated by the white there, the red indicates the areas of the chamber. And as expected, there is not much bone in that region there. And you can see that we are creating quite a reliable level surface here. Again, specifically focusing just along the distal media. First, we then move on to the distal lateral and as I said, prior will likely necessitate at least a 10 millimeter or augment, possibly a 15. However, in this case, mapping it relative to the special points, it looked like that a 10 millimeter augment would be appropriate and therefore we proximal the component another five more millimeters. And as we did along the media thermal condo, then appropriately prepare the bone, utilizing the handheld precision robotic mill. And you can see that we're painting away all of that bone and creating quite a reliable level surface there. We then move back to our surgical plan and therefore Vitalize the component back to its original plan, then we will move on to focusing specifically along the posterior conor defects. And as I said, the medial side will not necessitate an augment. However, posterior later will necessitate it likely a five millimeter augment. So therefore, I and that component plan another five millimeters then move on to preparing just isolated the poster lateral conor defect. And as we did along the distal femur, we then utilize the middle to appropriately prepare a flat level surface there to accommodate that augment. And again, this is creating quite a reliable level surface. And we are working really on a sub millimeter level. Here, here is the trial components and you could see a isolated distal media and an L wedge uh augment moly similar to the femur. We then prepare this in a similar fashion where we're first refining the bone to actually visually assess the extent of bone loss and then move on to the actual special points. And we'll be able to see that in a cross sectional view, the extent of bone loss. And therefore, you can see we're scrolling through in a cross sectional view here indicating that there is an extent of bone loss. And so therefore, in this certain case, I plan for 5 million meter proximal tibia augment. However, this can easily be made up with a polyethylene if you choose. However, in this case, I vitalized the component five millimeters to account for that five millimeter proximal tibia augment and as we did with the femur again, utilizing the handheld precision mill, we then prepare the proximal aspect of the tibia in quite a precise manner, creating a reliable level surface here. Um We then plan to prepare for a tub of cones and this should be done in a standard technique and provisionally prepare the bone. Utilizing the robotic mill. You'll see that the the cone has already been placed and then you place your final components per your standard cervical technique. However, it is recommended that short cemented 112 millimeters, fully cemented stems be utilized in this workflow. Then you fully cement the components in and allow them to cure. We then trial the components with the trial polyethylene in place, take it through entire arc of motion to confirm the excellent range of motion and alignment that we have achieved here. Then as we did during the planning stage, assess the extent of gapping by applying a very symbol stress throughout the entire entire arc of motion. And you can see here that we've created a well balanced total in the orthoptics with less than one millimeter gapping between the medial and natural compartments. After you were happy with the final components, you place the final polyethylene and um and you're done here are the final postoperative radiographs that show a very well aligned and well balanced total knee arthroplasty revision. Thank you very much for this opportunity to present to you the coy surgical system and the setting of revision, total knee arthroplasty. You'll find that this is an exceptional technology that can really help improve your outcomes and the care of your patients moving forward. Thank you very much for your attention.