Dr. Guild discusses how to drive a highly personalized approach to partial knee arthroplasty with JOURNEY™ II UK Knee System and key enabling technologies.
Hello, I'm Doctor George Gild from Atlanta, Georgia at Emory University. I'd like to thank Smith and nephew for having me on to talk about driving a highly personalized approach to partial knee arthroplasty with new implant design. So, first off, why even do a unicompartmental knee? Well, it's minimally invasive, it preserves the cruciate mechanism. The Patel thermal joint will have normal contact forces and pressures. The range of motion has been shown to be better than total knee better for demanding activities. Patients have better proprioception with equivalent pain relief and total knee satisfaction for a whole host of issues has been less. If you look at the red for total knee rep, uh total knee replacement patients, this is the percentage of patients that have difficulty with these activities and that has been borne out in the literature. We also know that hip replacement outcomes have been excellent. Patients in sport have increased their ability to do sports where total knee has lagged behind. And many of us have wondered how can we get a knee to be as good as a hip? One way of doing that is to consider partial knee replacements, they have faster recovery shown to have less opioid consumption, improve function, lower morbid uh lower morbidity and mortality, better forgotten joint scores. And in some studies has shown a decreased economic burden of the health care system. But doctor Gild, I hear all unis fail. Well, there is a 91% survivorship 20 years in a study looking at 682 medial unicompartmental knees implanted from 1983 to 2005. The median age was 69. None lost the follow up and 100 and 72 of those patients died with the implant. These are 30 year results for 100 and 25 patients at 25 to 30 year follow up and 90% of them. This was the definitive knee replacement procedure. But doctor G I can only do uni on very few patients in my practice. Well, if you go by the traditional Cosin and Scott criteria, it may be that only 6 to 8% of your knees uh would be able to have partial knee replacements. I'll remind you that this was not a study. It was actually an instructional course lecture with relatively restrictive criteria for partial knee replacement. And I would invite you to look at these next slides on radiographic decision making in determining who is appropriate for parenting replacement. And these are the criteria that I use daily in my practice. # 1 do the patients have bone to bone medial compartment, osteoarthritis on their A P weightbearing view or a Rosenberg view. Number two, is there a functionally intact AC L E G anteromedial osteoarthritis where the blue arrow is depicting that the femur is anterior on the femur and it suggested that the AC L is intact AC L deficiency is a relative contra indication of partial knee replacement. Three. If you're gonna do a medial compartment, you don't want full thickness, lateral compartment disease, that would be a no go four. You want a functionally normal MC L on a stress radiograph, it needs to correct to neutral if you can't correct them out of virus and you're leaving them in too much virus, they will fail in the virus. And this can also be seen on a 20 degree flexion stress view. Number five, you need an acceptable Patel, the joint on a skyline view. I will tolerate some medial facet osteoarthritis uh but bone to bone, lateral facet osteoarthritis as shown in the radiograph on the right would not be acceptable for a partial knee replacement. Other myths isolated medial pain is not a requirement. Anti knee pain may be acceptable for some patients and does not compromise outcome, patients age weight and activity level is also not preclusive of partial knee replacement. Contra calcinosis of the lateral compartment is not a contra indication or a small lateral marginal osteophyte or medial tial subluxation, which should correct when the partial meat is implanted. If the AC L is intact, also full thickness cartilage loss on the nine wa nonweightbearing surface of the medial side of the later from a condo is not a contraindication. Once you've decided to perform a partial knee replacement with the above mentioned criteria, then consideration goes into your implant choice and I'm gonna submit to you the following slides on what is the best choice uh in my practice? Certainly, uh and should be applicable to most practices. And that is the journey to unicompartmental knee replacement. Smith and nephew has a history of partial knee replacement design dating back to 1974 with the Marmur prosthesis. There have been several iterations over time including the genesis journey, Palo the joint, the journey uni acquisition of the Zook acquisition of the stride and today's journey to uni compartmental knee replacement. The journey to partial knee replacement is continuing in Smith and Matthew's uh legacy. It has excellent inter operative sizing flexibility. It has an oxy bearing surface on the femur which has been shown to have lower wear rates and is excellent for anyone with metal hypersensitivity. The instrumentation is optimized and it's a tissue conscious design. So why use a journey to unicompartmental knee replacement? We talked about this. It's gonna be a norm, more normal feeling need for your patients compared to total knee, even a perfectly done, total knee will still have more noise and not feel it as kinematic normal as a partial knee replacement. This results in very high patient satisfaction. And the journey to knee is built on the heritage of one of the most clinically successful partial knees. The designing of the journey to uni compartment knee. If you see there's some design features that are worth noting, there's a patella friendly contour which allows maximal positional freedom with a blended periphery that avoids overhang. The taper bases plate is also gentle on soft tissue and the tailored fit avoids overhang. The slim rail allows surgical access and there are specific medial and lateral tibial base plates. Other um aspects of the knee include divergent lugs for compression and deep flexion grip, blasting for cement, adhesion and lugs and akel on the tibial side for optimal stability to help prevent aseptic tibial loosening. Intelligent kinematics, designing the journey to uni was done with the life mod knee simulator system. The construct was tested with ideal implantation with reasonable surgical variation to ensure consistent performance through manipulation of 64 unique variables. The marriage between robotics and partial knee replacement, I'd say is exciting as it's ever been. And the Australian Registry in particular is showing improved outcomes with regard to lower revision rates, partial knee replacement. In combination with robotic assistant and Corey handheld robotics, I think is an excellent tool for the journey to uni we'll have another speaker speaking on Corey specifically, but however, the core robot is image free. It allows for real time planning optimized alignment and balance with safe and accurate, robotically controlled resections and the surgeon controlled handheld intelligence. For a modern robotic approach. I will also add, you can do patient specific uni compartmental needs of which I've done many with visionnaire uni compartment metal adaptive guides. There are medial and lateral guides uh with updated design. Uh The surgical variabilities are built into design. So it's great for getting your components size and positioning be vagus your section depths, rotation and slope. Uh There's personalized support from the in-house manufacturing. Uh the visionnaire imaging modalities, a knee MRI and a leg length x-ray. Uh The benefits are numerous including planning, streamlined surgical techniques, high surgical accu accuracy, increased O R efficiency in some studies. And it may reduce your O R inventory and cost real flexibility with the journey to partial need. Once again, it's a tailored fit. There are 10 right and left handed sizes in 2 millim increments. The bone preparation is grouped in three sets on the femur for intraoperative sizing flexibility. In other words, you can use for the same lug preparation use several different sizes of thermal component size for best positioning and balancing. This is the introduction of a lateral specific specific base plate for maximum coverage. There are eight lateral sizes, 10 medial sizes. There's highly cross link polyethylene in 8 to 14 millimeter thicknesses which come in one millimeter increments. So a very flexible partial knee with very few trays to open and close for your operating room and partial knee replacement. This is a maximum two tray modular set design and we're gonna go over a few features uh of the instrumentation itself. So there's an adjustable tibial guide um with sub millimeter recut adjustment options and a sagittal saw capture or you can use the shimmed tibial guide which is captured and un captured. The removable shim will allow for a two millimeter recut with regard to referencing depth. You can use a standard stylists to reference to your depth or you can use referencing spoons. Um a more gap balancing measurement tibia. There are two different ankle fixation methods. There's a medial ankle clamp and an ankle strap for tibial trialing and preparation. You can use conventional tibial trials shown above and prepare the lugs through the sizer with a self prepping keel or you can use a hooked and non hooked version of the tibial uh trials to prepare your lugs and keel through the sizer itself. And I've done it both ways. My prefera my preference is the one on top. Uh but this will suit most surgeons for thermal trailing in preparation. You can choose to drill your logs through the thermal trials. Um trial range of motion prior to lug pre preparation. There is a spiked rail that allows medial collateral shift. You can prepare the lugs through the trial or you can use conventional thermal trials and prepare the lugs through the cutting block. So journey to your unit compartmental knee replacement and summing. This is intelligent kinematics, excellent design optimized with life mod and knee sim leverages key features of a legacy system works great with enabling technology compatible with all Smith and Nephew enabling technologies including robotics and visionnaire system, real flexibility with tailored fit with compartment specific specific side uh tial base plates, inter operative sizing and flexibility, small increments with many sizes for anatomical coverage with intuitive technique and instrumentation, a modular two tray system and it uh can cater the instrumentation to your preference. So this has been a home run in my practice, I would say offering partial knee replacement to a much higher number of patients than I was able to in the past and having a versatile system that has been working great. These two week visits when they come back with excellent range of motion and they're starting to talk to me about playing tennis has been a much different office visit than my total knee uh visits. Once again, I'm Doctor George God. I'd like to thank Smith and nephew. Thank you very much.