TKA_2 — Full Surgeon Narration
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but this will be pretty much a traditional approach doing primary toe knee replacement. So I'd like to thank Cindy, first of all, and Michael for my great assistance today to doing this video. So first of all, we're going to do our skin markings. Some landmarks we look at is, first of all, the patella. So we like to mark pretty much your medial, lateral, and superior inferior borders, and also helpful to put your thumb on the tibial tubercle. And oftentimes, they just outline that so you know where your tibial tubercle is. In his case it actually looks like it's a little bit lateralized. You can see the tibial crest right here and usually he may just hold the leg like that. Usually I'll go pretty much two finger breasts above. Obviously incision size can vary based on surgeon preference but this is probably pretty standard and then I'm going to come right over the front of the knee splitting the mid-pole of the patella and then coming down. And usually that's ending up on the medial border of the tibial tubercle. So okay, so we'll start right there. I like to make my incision inflection, but this can also be done in extension as well. So here's our incision. This incision might be a little larger just to get better visualization for this cadaveric demonstration. So first thing just going through this initial skin and sub-cute tissue, you can see that what we want to do initially is get through this layer where you can really peel back. So here you can see the patella and when you pick up here you can really easily peel back this tissue on both the medial lateral side and usually you're trying to peel laterally until you reach a lateral aspect of the patella. You don't need to make large tissue flaps and then basically most surgeons here at HSS do a medial parapetela approach and that's what we're going to do today. We like to mark in one or two locations prior to your Arthrotomy, which helps you get a better idea of what's going on in your life. And if you have any questions, feel free to post them in the comments below. And if you have any questions, feel free to post them in the comments below.

And if you have any questions, feel free to post them in the comments below. surgeons here at HSS do a medial parapetella approach and that's what we're going to do today. We like to mark in one or two locations prior to your arthrotomy which helps for re-approximation at time of closure. You can do this with either a bovie or a knife but for the medial parapetella arthrotomy you want a two millimeter cuff approximately. So you can see your VMO, your saw spot which is right in between the VMO and the and the medial border of the patella So I like to make that that 2 millimeter Cuff of tendon come along in between the VMO and the patella here angling your blade Slightly like this so you're coming below the patella and then once you see the patella tendon you're basically coming straight down onto the proximal tibia and then basically just coming up here and completing that arthrotomy. Once you do that, you can basically sublux your patella and now you're looking at your fat pad, so I'll basically resect some of that medial fat pad. You can remove the fat pad either in flexion or extension, I'm just showing it to you right now in flexion where you can use this right angle to protect the patella tendon and then everything here you can remove. In terms of how much fat pad to remove it's up to the surgeon. I usually like to leave a little cuff of fat pad to protect the patella but basically you remove as much as you need to to see your proximal tibia. So here I just released the lateral meniscus, the ACL off its insertion, and the PCL off of the notch. I do these releases early to basically free up the knee and then also looking to basically cut and find the the medial meniscus, the anterior horn right there. And once those are my releases that I like to do inflection and then I'll come out to extension. So I'll show myself this super teller fat pad. I like to basically elevate the fat pad in a T like fashion so you basically come in right down the bone and then elevating it both medial and lateral. Oftentimes this will be done with with cautery because you can have some bleeding here and we're trying to show ourselves particularly this anterior lateral femoral cortex so we can get correct femoral sizing. And then here I'll do my, we have a bovie there, okay. So now I'm actually switching, we do have a bovie here, doing my medial subperiosteal appeal. A key thing of this part is not to make several marks distally because you want to have an intact distal sleeve. So I basically want to release proximally first, there here, and And I'm basically doing this peel. Now the amount of medial periosteal release is dependent on whether it's a varus or valgus knee. Valgus knees, obviously this will be less than in a varus knee, particularly in a uncorrectable varus knee. But basically once we get to the mid-pole of that that mid tibia that's a good location where you can stop. Some people will use a thin bend at this point and will insert it here to assist with additional soft tissue release so we can put that medial sleeve under tension and then complete it. You can do a little bit more of a release as needed but I think that should be sufficient here. at this point, now I'm basically ready to flex up the knee. I have one retractor here that's below the MCL, which is right here. A second retractor, hold on. A second retractor will be placed laterally. I like to put it underneath that lateral meniscus so it's tucked inside of it. And then it comes out laterally and really gives you a nice exposure here. Now in terms of your starting point to enter the intramedullary canal the femur your PCL was right here you want to be one centimeter anterior to your PCL insertion which is roughly in that location and then I have a sharp tipped drill to enter the distal femur. When you enter the distal femur I think it's helpful to first aim slightly perpendicular to the face of the cartilage come come in here and then angle up the canal. And oftentimes you can put your index finger on the anterior cortex, so you know you're directing directly up the canal, just like that. Now, we have a sucker tip. We like to suck out the fatty marrow, so we don't have any, we decrease the amount of fatty marrow that's embolizing. We take our intramedullary alignment guide for the distal femoral cut. Just confirm that you have five degrees of valgus. Usually that's what we use based on the pre-op template. This is for a, so you wanna make sure here, this is actually for a left. We wanna switch this so it's for a right knee. So it's five degrees. That's a good example why to check that. So that's for our five degrees. So always check the distal cut prior to insertion. And this is gonna come down inserting into the intramedullary canal. And we basically have our paddles touch the distal femur and then have two pins placed into the distal cutting block here.

Good. I think it's helpful to look at your pre-operative template and to see that the way that the paddles are touching the distal femur is replicated. So if you predict that you should have a two millimeter gap between the the distal paddle and the lateral distal femur, you should replicate that intraoperatively. Patients with severe flesh contractures greater than 15 degrees, you could consider doing a cut plus 2 millimeter resection. Less than 10 degrees, I think you usually can make a standard resection and then try to do your releases of your posterior capsule and posterior osteophytes. So basically I'm gonna remove this here. That comes out. And here, I just wanna show I've got my two retractors placed protecting the MCL as well as my lateral structures here. Okay, good. So that's the, you know, hard bone sending a nice job with those cuts. You didn't see the saw rattling. It was smooth in the cutting guide. You can see here that we're basically at the base of the notch. You can see here that we call this like a butterfly where it's not two individual condyles, but it is connected through the notch. So probably our depth of resection is appropriate. Okay, we'll take, we can leave those those pins in. Now we'll go to our proximal tibia, let's take another thin bend. So the move here basically is to take this thin bend, place it posteriorly, a little bit posterior medial, the flex and externally rotate and deliver the proximal tibia, and then back like that, hold that that and then basically put our retractors back in here and then immediately here so we have our three retractors in position we have good exposure of our proximal tibia sometimes if there's you know a little bit more anterior translation you can release a little bit of the posterior aspect of the meniscus and a little bit of the piece posterior you know the PCL insertion but here we have pretty good exposure of our proximal tibia we'll then take our tibial cutting guide which has an adjustment here for slope there's valgus and then the height of you can position where you want to position your cutting block proximal distal and this is our basically our two and ten millimeter caliper to help with our depth of resection. We place this around the ankle here usually depends on the system but for this system i like a two finger breadth this is for our slope so i can put my fingers on the anterior tibia and I have a two finger breadth for my tibial slope. Usually on Moe's guide, it's one click or approximately five millimeters medial. And I also want to just palpate the anterior crest of the tibia and the anterior tibial tendon, confirming that this is in line with the distal aspect of my cutting guide here. And then basically adjust the depth of resection right here and a cadaver with no arthritis usually taking 10 off the normal side is what's better. One other thing I like to show you here with the cutting guide is that there's a line here that's directed to the PCL insertion through the tibial spines and that's for my anterior posterior slope. This guide has three degrees of slope so it's important to have that directed in an anterior-posterior direction. So I have my 10 millimeter stylus positioned on the lateral compartment. Usually on the defective side if it's a varus knee then you'll usually take two millimeters off of the defective side. Okay just put a pin there and then one more. We just basically tap these pins in like that and then once again we'll take a cocker. And one thing that's important here, first of all it's important to see that I've got three retractors placed, medial side, posterior, the lateral side is protected. You can also sometimes take an additional right angle to protect your patella tendon as needed. So if you need it, you could put a retractor like that and then that really would protect you from having any injury to your patella tendon. You want to start usually on the medial side which is the harder side here. Come through there, basically making sure that you're flush with the guide. I have one hand against the tibia holding the guide like this and you want to make sure that you're smooth in the cutting slot. Sometimes you can hit the pins if they're a little bit problem. Oftentimes you can see that proximal segment move when it's been released. Sometimes it won't move or you can't really make a clean cut in one go. So you'll stop, take your osteotome and kind of come in here and do a little bit of a additional release just kind of freeing up that bone okay and then here you're going to grab this with a sweetheart on the medial side and grab that and then basically peel it from medial to lateral releasing it you know post shear part of the meniscus insertion the pcl insertion and it starts to kind of give medial to lateral here okay that is being careful here that final little release here so we got in one piece so basically there's our tibial cut measuring probably about 10 millimeters off that lateral side. So at this point, you want to check your tibial cut. I like to take the, you can do it with a spacer block or you can do it with the, what you templated for sizing and you can template that off your pre-op x-ray or off of your tibial cut where you can put it on there and see what that looks like. And that looks pretty good. And I'll place that onto my proximal tibia. If you're trying to get an idea overall what your cut looks like, placing it flat on the proximal tibia. I think it's important so I can show this to you guys how this comes down the anterior aspect of the tibia. Just focus down here. You want to feel the anterior tibial spine. You can almost see that anterior tibial tendon rolling over my index finger and I want to see that that rod is basically overlaying that right down at the ankle. You could look at the second ray but that obviously is dependent on the foot position and then here I can look at my slope and then I'm basically parallel to the proximal aspect of the tibia here. So overall I think that tibial cut looks looks good. I've done those those cuts now I want to assess my gaps so what I'll do is I'll take the retractors out I'll bring the leg out to full extension here and my goal now is I want to look and see if I'm balanced medial and lateral. I have these minus blocks which are actually three millimeters smaller than the real and I'll work my way up to the 10 block so I insert that minus three and what I want to look at now both medial and lateral is my overall balance so I put my hand on the right now behind the ankle and my left hand at the joint line I'm applying this valgus stress and I'm looking for millimeters of opening and if we can just see here that right now i have about three millimeters of opening medial about three millimeters of opening lateral so overall here i've got a balanced knee that should be able to fit a 10 block once we do our additional releases i can try to insert the 10 block it's going to yep it goes in and i think that that's going to be pretty good with a one mil medial 1mm lateral. So that's a balanced knee and extension. When I've achieved that, I can then basically decide that I can take out my pins because I don't need any more bony resection. And this knee, which had minimal deformity preoperatively, does not require any additional soft tissue releases. So I now can proceed with setting my flexion gap and my femoral component rotation because I'm now balanced in extension. I think that's a pretty straightforward traditional workflow for performing a toe in the arthroplasty. So now that I'm back in flexion, I take these thin vents and once again place it inside the MCL, place this one laterally just outside the lateral tibia there. Some important landmarks that we often talk about are the AP axis here which is also known as white side line which is the the most the deepest aspect of the trochlear sulcus which is some right about here and that's going to come down and split the uprights of the femoral notch and so this is my AP axis right here and that should be perpendicular to the trans epicondylar axis which is basically the sulcus of the medial epicondyle which I can basically palpate with my index finger here and the most prominent aspect of the lateral epicondyle which is here when you connect these two lines these two should be perpendicular to one another. In a standard varus knee, usually I think setting the guide to three degrees for most patients will be accurate and you can see here pretty clearly that that three degrees of rotation for the right knee, this line is basically parallel to what I drew for the trans upper condylar axis and looks also parallel here to white sides line. So then I'll drill and you can see once I've drilled these two holes how this correlates with what I drew for Thank you very much. Thank you very much. Thank you very much.

Thank you very much. Thank you very much. Thank you this before I do that, I'm just gonna size this. So usually I like to put this slightly on the slope, going in the lateral aspect of the disulfimer here. So when I'm looking at my guide here. That size is a nine, so I'll start with that. And you can see pretty clearly here that the two holes I drilled for my thermal rotation are spot on with what I drew for my trans-lumbar columnar axis. I'll take my four-in-one cutting block, put that in, and I'll take an angel wing. Now with a posterior referencing system which you can see right here listed as p-ref as opposed to anterior referencing the risk is anterior notching. So you want to double check to make sure that I'm clearing the anterior cortex and I can see that I'm coming just above that supralateral cortex so I'm good. So at that point then I'll pin the guide. Now one thing that I like to do is actually check my flexion gap with my spacer block at this time to make sure that I have a balanced flexion gap. This is actually more of a hybrid approach. Okay put that down like this. Okay good. So I'll take this minus five millimeter spacer block and I'll put this in flexion at 90 degrees what I want to do now is I want to check my gap medial and lateral so here I'm testing it I have a one mil two mil gap on the medial side and lateral side. Here's my 4-in-1 cutting blocks. We like to start with the anterior chamfer. I like to start medially because if you're going to notch, the highest risk is notching on the lateral cortex, not medial. I'd like to see if my blade is going to come through and I'm going to see my blade come out and on anterior to the anterior femoral cortex. If I do then I'm okay and I'll go lateral. Okay good and then basically once you remove that anterior bone you can check and make sure that you're flush with that anterior cortex here. I'll bring it out to extension a little bit here. You can see the what we call the grand piano sign, which is basically in the anterior cortex looking like the top of a grand piano. And that's just a sign that you have appropriate external rotation of your femoral component. So here I come. And basically here, I have my one hand against the tibia. I'm basically seeing that I'm still in bone. Sometimes always a question of how far posterior to go. But you can see that I'm still on bone. And you should feel a little give when I go through the posterior aspect of that posterior femoral condyle. There, it just went through just there. And then come on this side. And once again, you wanna make sure you have appropriate retractor placement protecting your MCL and your lateral structures. There we go. There we go, anterior chamfer here.

Okay, that's our anterior cut. And then the last cut we use is the posterior chamfer. In terms of order, anterior, posterior, anterior chamfer, posterior chamfer, usually that will make for the most stable cutting block. So here's our posterior chamfer. Okay, so then now we can take out our four-in-one cutting block, curved osteotome, we have it down below. Okay, I'm going to remove all these bone cuts okay at this point we progress to a lamer spreader now this bone quality is quite good but if you have poor bone quality sometimes we'll place a angel wing or ruler to protect the tibia from having depression with that lamber spreader. Just place that here and then usually we use two cokers one grabbing the meniscus and then one grabbing just that peripheral capsular tissue right about here and then you can see that junction we want to go right at that junction you can leave a little meniscal cuffs so here right at that interface now the key thing here is that obviously you don't want to go medial to the medial border of the tibia as the mcl is quite close but you can see here that i'm inside the medial border of the tibia so i should be safe and i can basically go right back and remove that medial meniscus here like that and your MCL is sitting you know fairly close so at this point now I want to go and remove any posterior osteophytes this cataract specimen doesn't have any but you want a curved osteotome and basically like to do here is that you can see there's this white cartilage line that's in every specimen and everything that's behind this white line is osteophyte Right? Usually, we're going to do a little bit more of that. We're going to do a little bit more of that. We're going to do a little bit more of that.

We're going to do a little bit more of that. We're going to do a little bit more of that. We're going to do a little bit more of that. We're going to do a little bit more of that. We're going to do a is that you can see there's this white cartilage line that's in every specimen and everything that's behind this white line is oceophyte. Usually what I'll do is I'll go one millimeter in front of that white line, I think you can see here, and basically remove that. And sometimes that will also release a little bit of posterior capsule along with it. After that, usually we'll free up whatever osteophyte that I've freed up with a curved or angled curette, and then I'll take a ranger after that. So basically, you're sort of sweeping in that posterior capsule or region. This cadaver doesn't have any, so it's sort of make-believe here, but then you're gonna take a ranger, try to grab that osteophyte, and then pull pull it out ranger is blunt in this posterior capsule there so it's pretty safe particularly the medial side obviously the papacylar artery is lateral to the midline once you clean that out and you're happy with that you can come on the medial side and open and put a lamer spreader medially and then do the same on the lateral side oftentimes you'll have a right angle just protecting that patella tendon. And then once again, coming here with either bovey or knife, usually bovey, releasing this. Now here you can see releasing that lateral meniscus and you want to take that posterior until you reach that sort of poppiteal hiatus. And that'll kind of let that lateral meniscus just sort of come forward freely leaving the popliteal tendon intact behind which is right there. And then you can also at this point release any additional ACL or PCL attachments as needed in the notch there. And then the same thing here I'm going to take that curved osteotome as we did did before, we kind of already showed it here, we're going to do that white line, one millimeter in front of that. And then basically angle, come in and release that bone from the posterior aft of the condyle, sweep it with your curved curette to release it. Sometimes it can be a little bit difficult because it can be stuck behind that poplar tendon. Come in with your open ranger and grab that piece and try to clean out whatever you have posteriorly and palpate to make sure that bone has been removed. So at this point you want to proceed then we're looking at your spacer blocks. We'll take a 10 block here and we want to insert that at 90 degrees of flexion. Bring the leg out to 90. Put that in here. I like to bring the patella tendon over to reduce it and then basically check my block and flexion. So you want to basically take the block and you want to move it medial and lateral and ideally you want the block to pivot centrally in the knee. If you have a medial pivot where you basically have the block pivoting like this, it probably means the medial side is too tight. If it's a lateral pivot where it's pivoting on the lateral side but not the medial but not centrally, then your lateral side is probably too tight. So you want to have a symmetric pivot inflection with the patella reduced. When the patella is dislocated or subluxed, you're obviously tightening up that lateral sides. You want to test the knee with the patella in that reduced position and make sure that the block is translating centrally. Now this cadaver here has a little more gapping lateral than medial. You can look and see, I think this lateral side was a little loose in this cadaver. The popatiel tendon is intact. So in this case, in a gap balancing model, you could proceed with more external rotation to close down that lateral side and measure a section model. You're going off of your anatomic landmarks and sometimes proceeding with mid-level constraint is needed to have a balanced flexion gap on the lateral side. We do tolerate more lateral-sided laxity which is normal in a native knee than medial-sided laxity as that is more representative of normal kinematics. So then we'll come out to extension like we did before so here's our knee now in full extension checking immediately you can see here it's all the top. We've got a one two millimeter gap on that medial side which is good and one two millimeter gap on the lateral side so we have a nicely balanced gap and extension with a 10 millimeter spacer block. So at this point we then can proceed with pinning the tibia and setting your tibial component rotation. So basically just put those fin vents posteriorly, good, okay. So here you can see tibia, sometimes hyper-flexing can bring that tibia into view in a little bit better view here. In terms of tibial rotation, there's multiple landmarks we can use, one would be the medial to middle one-third of the tibial tubercle, which is here, and that usually goes down the anterior crest. You also can have a line that goes back into the PCL insertion posteriorly, and then also that you'll see you can drop a rod and make sure that that rod drops down the tibia right down in front of your anterior tibial tendon as we looked at previously. So I'm going to put one of these magnetic pins right there immediately. Okay good and then I'll basically put my drop rod in here and like I showed you basically try to have so I can see here the drop rod if you can see this is basically coming down directly into your crest and it's right over the anterior tibial tendon so I'm happy with that component rotation and we'll take a magnetic screw now we pinned the tibial component we're happy with that come out here now. We'll basically place our Femoral trial so here's our femoral trial Right there now what we'll want to see here is I'm basically flush with the lateral Cortex we want to be lateralized on the femur to improve the tele femoral tracking Tap that down and then we'll look to make sure that we have good coverage and take a crude acetone and a ranger just remove that so then basically remove the soft tissue that's remaining here in the notch and then basically I'm ready to place my sled, It slides in from the top here. Good and then I'm basically ready to take my poly. This is the poly right there. Good. I'm going to bring that knee out to extension and sometimes you need to do a little bit of a push to gain full extension. What I'm looking for at this point point is I wanna see number one, that the knee is out to full extension, okay? The second thing I wanna see is that the tibia, tibial trial and the femoral trial are coapted with each other in full extension that I don't have a rotational mismatch. Then I also wanna check that I have good medial lateral stability. We checked it with our spacer blocks, wanna check it again with our trials. So I'm seeing that we have a one two millimeter play on the medial side and a one two millimeter play on the lateral side. And I wanna basically flex up and make sure my patella is tracking well in the groove if I need any lateral release or to assess for that. Lastly, obviously I wanted to check an inflection to make sure that my AP stability is acceptable so that with the leg at 90 degrees and anterior shuck you want to make sure that you have ideally less than five millimeters of anterior translation and inflection. So at this point here, evert the patella, take two cokers, one inferiorly, one superiorly, and we take a sweetheart. We place right here and I have a caliper. I want to measure the thickness of the patella at the highest part. So I want to recreate the patella thickness. So this patella measures 24 millimeters in diameter. I then take my patella saw here and I like to place my index finger you can do is different ways index finger below the patella can look at your quadricep tendon insertion your patella tendon insertion you basically want to have your saw blade be just above that measure 24 millimeter so I'm looking for about a 16 millimeter residual patellar thickness. I want to come out of here, so at this point sometimes this sclerotic finishing the patella, I'll take that caliper. What I like to do is measure four quadrants here. So I want to make sure that each of the four quadrants is what I want based on the patella thickness. So I'd want 15, 16 millimeters. And if it wasn't, I could go back and take a little bit more bone to make sure that each of those four quadrants is the correct patella thickness. And then here you want to size it. This may be a little bit big. I mean, you're basically looking for your patella sizing that you are within the confines of the patella without any overhang. Might be a little bit easier for us to go with a one smaller size here so I'm just checking to see that I can basically be inside the confines of that patella. You want to make sure obviously that I don't have any skin that I'm going to be pinching with my patella guide here. Place it right there on the medial side to that also assists the medial aspect of the patella to assist with patella tracking at that point. Yep now it's now down make sure it's flush and then basically take the guide and drill those three holes and take that patella button place that and oftentimes what we'll do is if we have a little bit of lateral overhang to prevent that lateral facet impingement we'll take the saw and just resect a little bit of that overhanging lateral facet right about there just to make sure we don't have any uh lateral facet impingement and also you can perform a little bit of an inside out laterally sometimes by freeing up that retinacular tissue there at this point we're basically ready to look at our final trialing out. The patella is in place. Okay. Take this out here and then take the knee through its range of motion. You can see here the patella has a little bit, it centrally attracts well here, I don't know if you can see that, you know it has a little bit of a tilt so sometimes you want to check you know with a sweetheart before you proceed with a lateral release. You number one want to check that the tourniquet is down, you don't want to do any lateral releases prior to letting the tourniquet down. Number two it's helpful to bring bring that medial retinaculum together, and then to look at that patella tracking, and with the retinaculum closed, you can see here that the patella actually has no tilt. If you did see tilt, what I like to do is have the knee at about nine degrees of flexion. There are different ways to do a lateral release, but it's my preference to then take a bovie, to have the knee nine degrees of flexion, and basically come about one centimeter lateral to the lateral border of the patella and to basically release an outside in fashion some of this tissue here and I like to try to leave the medial, the deeper layer of tissue intact so I do not like to make a full thickness lateral release and usually what you'll see is that this tissue will kind of reflect back because it's under tension and then you can basically check to see that you no longer have that lateral tilt present. You can titrate the amount of your release necessary based on how much of a patellar tilt you may have and some of you can bring it out in extension and give a little pull just to stretch out that lateral tissue. It's not really full thickness so you shouldn't have any issues with the hematoma and then check your patella tracking again. So here you can basically see we have a well tracking patella with a knee that is balanced in full extension and has less than five millimeters of AP shock and it has well coaxial