Anteromedialization procedures have been well documented as an effective treatment option for the correction of patellofemoral malalignment and to unload the lateral patellar facet in deep flexion.

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The anatomic double-bundle technique replicates the native shape of the medial patellofemoral ligament (MPFL), provides stability in both flexion and extension, and effectively limits rotation throughout ROM, helping minimize postoperative instability. The technique, if accomplished directly and anatomically, can also allow for more aggressive rehabilitation protocols and earlier return to activity.1
Successful MPFL reconstruction is dependent on anatomic placement of the graft. The technique incorporates the use of a femoral template to ensure proper placement of the graft in the femur. This position provides a static fixation point that equalizes the tension across the graft in flexion and extension, thus helping minimize stress across the patellofemoral joint.
Other options include Knee FiberTak® anchors for onlay MPFL techniques as well as 4 MPFL convenience packs to address each patient's unique needs and each surgeon's fixation preference. The newest kits use 3.9 mm BioComposite SwiveLock® anchors for patellar fixation and either a 6 mm × 20 mm BioComposite FastThread™ interference screw or an ACL TightRope® implant for femoral fixation.
Reference
1. Schöttle PB, Hensler D, Imhoff AB. Anatomical double-bundle MPFL reconstruction with an aperture fixation. Knee Surg Sports Traumatol Arthrosc. 2010;18(2):147-151. doi:10.1007/s00167-009-0868-z

Jonathan Riboh, MD (Charlotte, NC), demonstrates an all-epiphyseal, all-onlay MPFL reconstruction using Knee FiberTak® anchors.

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All-Epiphyseal, All-Onlay MPFL Reconstruction Using Knee FiberTak® Anchors

My name is Jonathan Ribot. I'm here today from Charlotte, North Carolina, and I'm going to demonstrate for you guys an all online mpfl technique. So the instrumentation we need for this technique is shown here. We have a dedicated 2.6mm drill bit. It's really important to use this drill bit on the patella. The bone is hard enough that you do have to use a drill before putting in your anchors, and then on the femur to identify our location for the mpfl. We'll use a standard 2.4mm pin on the femoral side. My preference is to use this double knotless FiberTak anchor. It's a 2.6mm anchor, and it allows two knotless loops to fix the looped end of the graft on the femur. And then there's two different ways we can do this on the patella. One is with hybrid FiberTak anchor that has both a knotless pre looped, as well as a sliding suture that has needles already on it to reinforce that repair. The other option is to use the 2.6mm FiberTak button, and we'll demonstrate that in the in the cadaveric specimen. The final piece that we'll need is this 0.9mm SutureTape loop. This is nice. For a smaller graft, you might be using a gracilis in a smaller patient, and you don't want to have excess of suture load at the end of your graft. You want good collagen for healing. So this 0.9mm loop is really handy for that. So for an all online mpfl reconstruction, we'll use standard incisions. I like to mark out the 50 yard line of the patella and center my incision around the 50 yard line. You don't need to go any more proximal than the proximal pull of the patella. And here I've made this incision a little bit longer than I would in a real case, just for better visualization. On the medial epicondyle side, you can often palpate the adductor tubercle, which you see here in the medial epicondyle. As we know the graft will go right about here. In between those two I'm just going to make a slightly longer incision for ease of One important landmark I always want to identify is the muscular portion of the VMO, which you can see right here, mainly so that you stay out of it. It can cause significant weakness in the patient if you end up cutting into the fibers of the VMO as you make your exposure on the medial patella. So we always want to understand where that muscle is. And so one tip on the approach is as we know we want to be in between layers two and three, I actually don't expend much energy on trying to identify one. And two. It's really easy to identify three. So three is the capsule and it's got this yellow purple hue to it. It's very vascular. Whereas if layers one and two you can see our white and striated. So you can simply cut through the white tissue until you fall until this fatty yellow purple layer. And that's always going to be your interval right there. We've got the medial patella exposed here. And we want to roughen this bony surface in order to get a good healing surface for our graft. You see I've marked on the skin the 50 yard line, and that is a good landmark. Our first anchor is going to go in typically right at the equator of the patella. And it's important also to position this properly anterior to posterior. And so I have made a small capsulotomy here to show where the cartilage is. And you can see this is the cartilage right here. This is the anterior cortex up here we try to find ourselves halfway in between. If we get too close to the anterior cortex, we put ourselves at more risk of fracture. So for our second anchor, we're going to want to go halfway between the equator and the superior pole, which is about here. So if we have that distance, that typically puts us near the top of our exposure. As we prepare to drill into the patella, we have to remember that this is a very hard bone. And so we're going to always want to have an assistant give us counter pressure on the lateral aspect of the patella. That will really help stabilize that for us while we drill. So as we drill our patellar sockets to put in our anchors, we will use this knee specific drill guide. Once again, this is a pistol grip. It's very ergonomic and comfortable in your hand and has a shorter working length that's more convenient for open surgery. So the end of the drill, you see, has a crown tip that will engage nicely with the patellar bone and prevent it from sliding as you drill. So we're going to show two different ways of fixating the graft. The first option is going to be this hybrid 2.6mm that has both a pre pass loop for knotless fixation as well as some needles. And that's how we're going to recognize this anchor is that plastic sheath on the handle of the inserter that protects the needles. And that will allow us to reinforce our repair. You can also use those sutures additionally to repair your retinaculum down to the patella for a medial imbrication in addition to your mpfl reconstruction and as we drill into the patella. Given how hard the bone is, I'll typically cycle this 2 or 3 times to make sure we're removing any debris. You want to keep your guide hand nice and steady, and you see how easy this is to do with this shorter handle. We can slide our anchor into the inserter and then with good counter pressure on the patella we can tap this in. And what you'll see is you want to get all the way to the hard stop where your anchor abuts the drill sleeve. You can then remove the tab that releases the sutures. You can then remove the protected needles out the back of the guide and unwind those. Once your sutures are fully unwound, you can remove the inserter and remove the guide. So for setting the anchor we're going to want to grab these black sutures. These are the ones you can see that are attached to our needles. And these are going to allow us to set the anchor. So slow and steady retrograde pressure here will allow the anchor to deploy. And I'm applying maximum force here and getting no displacement of that anchor. If you could see that there was a small pop allowing that anchor to set. Knowing that we've got secure fixation. Another feature that you'll notice is that this is a SutureTape, and this is our first knotless anchor that has the SutureTape. So you have less likelihood of cheesewiring through your graft, particularly with the small gracilis graft. So this is going to help with fixation strength. So this is the second anchor option for the patella. And this is a 2.6mm FiberTak button. We can recognize it by these two loops at the top of the inserter. So with these anchors you always want to make sure you unwind the sutures before you pull the inserter back. So here you can see they're fully free. So for setting this button anchor, you're going to want to grab all four strands as one. And then again apply retrograde pressure until you feel the anchor deploy. It's very important on this all Onley technique that we get below the fascia as we try to put in our soft anchors. And so we do want to make a sharp incision into the fascia to allow us to get directly down to periosteum as we do our drilling. We can then place our self retainer deep to the fascia, and we'll be in the perfect position to do all of our work. This elevator is on the medial condyle, and you'll see that it falls into this recess, or this sulcus just proximal and posterior. And that is the exact location of the mpfl origin, the sulcus in between the medial epicondyle here, the adductor tubercle here. And once again, there's a sulcus right here. This can be confirmed fluoroscopic using the standard techniques. An important point here is that you have a choice in the trajectory of both your Pin and where you're going to put your anchor. Depending on your particular patient, a more traditional pathway is going to be to aim anteriorly and proximal. This will obviously keep you out of the joint. This can be a challenging angle in a younger patient if you want to avoid their faces. What you can simply do is raise your hand such that you are now aiming distal, as well as lowering your hand to aim anterior, and this will avoid the FICA, the notch and the joint surface. You just can't drill all the way across the femur in order to avoid overpenetration with your pin. In a younger patient, I like to mark the drill bit at 2cm or 20mm. That's been shown in cadaveric studies to be a safe distance where you're going to avoid injury to the trochlea, the notch or the phycis. So at this point, we'll advance our 2.4mm pin right up to the mark that we've made to avoid any over penetration on the femoral side, we're going to use the double knotless FiberTak shown here that has two pre passed knotless loops for fixing the femoral side of the graft. What I will do is I will slide the drill guide over my existing pin. Engage it here. And my assistant is going to provide counter pressure on the lateral knee holding the shaft of the guide to make sure it doesn't move at all. I can then easily remove my pin, and after we've inserted the anchor all the way to the hard stop, we can undo our black tab and unclip our sutures. I can then remove the inserter and remove my guide. So you'll notice here there is a white retaining suture that prevents me from accidentally shortening my loops. And I need to remove that. And to set this anchor I'll take a probe. You could use a switching stick or any similar device. Put it into the loop, and I can then use this to apply backwards pressure to set my anchor robustly. You don't want to pull on the tails, as pulling those tails will shorten your loop, and might leave you in a position where you can't pass your graft. My graft prep is actually very easy. There is none. All I do is I put an allis clamp on either end of the graft, and I mark the central portion of the graft as that is going to line up. You see here with our femoral anchor, to have the looped end of the graft on the femur. A nice option for passing the graft through the double loop is to have your Allis clamp already there. I can then hand off the graft to my assistant, who will pull it through very easily, and we will center that purple mark right inside the loop. I will then have an assistant hold the graft on either side so my hands are free. One thing I have learned in using this technique is if I pull down on my shortening sutures while the graft is engaged against the tapes, it will roll up the graft. And so I always ask my assistant to be one step ahead of me. And what I mean by that is they will have the graft 1 or 2mm away from the top of the loop, and as we progressively shorten it, they will follow me down so the graph does not end up rolled up. I will start here with the blue suture. And you can see as I shorten this, my assistant is constantly staying 1 or 2mm ahead of me. These SutureTape slide very easily down and as soon as I pull that all the way down, you can see just how robust and easy that fixation is. I have my second tensioning suture here, my black suture that can simply be pulled down in a similar fashion to augment the strength of our fixation and femoral fixation is completed at this point. If you grab the graft, you can see that it has robust fixation. Our two limbs are nicely fixed at this point. So I'm now going to shuttle the graft basically between these two. So I'm going to pass this clamp I'm going to get this clamp all the way through here. Do you see that. And I'm going to open it up. And we're basically going to pass the two limbs. At this point I can take a curved clamp and pass it between layers two and three, starting on the patellar side and ending at my epicondyle incision. I'll then sequentially pass my graft. I'll take the proximal limb first, and I can hand this off to myself and easily retrieve this on the patellar end. We'll then make sure to pull this clamp proximally, to make sure that we don't cross the limbs of our graft underneath the layers. You'll notice here that as I've passed my clamp a second time, I've made sure to stay distal to the first limb, and I can then hand off the second limb to myself. And that comes very easily. And we once again make sure to pull this more distally so that the graphs are not crossed. This is a final view of our femoral fixation construct. We can see an all onlay fixation here with our distal limb of our graft and the proximal limb of our graft, with a nice layer in between those. So they are taking separate trajectories both underneath the fascia which is this layer right here. So now we are ready to fix the graft on the patella. Typically for this, I'd have the knee in resting on a bump around 45 degrees of flexion, and I simply leave the patella where it wants to be in the trochlea. In that sense, I'm using the mpfl simply as a check rein. I'm not trying to pull the patella over medially, which will avoid issues of over constraint. As I lay this graft down, I can mark exactly where that graft is going to meet the suture anchor on the patella. And that will be my guideline. So once again, if I lay this graph down right here at that layer, it will be in perfect tension and not over constrained with this hybrid anchor. I can have my assistant place a clamp through the repair loop, and I can hand off the graft to the assistant. And now I will use the blue pulling Strand to shorten this limb. If there's any concern about the graft slipping through the knotless loop. We do have these nice black sutures that are suture tapes preloaded with the needle, and I can use those to reinforce my repair. At this point, we have a couple of options. We could use our FiberWire scissor to simply cut these tails. Additionally, we could leave these intact with the needles on them if we wanted to use these to augment our retinacular closure. What we can cut at this stage is the blue suture that has tightened down on the graft. And that's option one for patellar fixation. At this point, we can cut off the excess graft typically sharply. You want to leave about 8 to 10mm of space here. If you cut too close to your sutures, if there's any slippage of your knot, it could cut right through the graft. And so I'll typically leave about a centimeter of tissue. And that's some added collagen for healing. So the second option for fixation on the patella is patella is to use this button construct in a very similar fashion. With the knee around 45 degrees, I will simply lay down the graft and I will mark exactly where it wants to overlie the anchor. This is particularly important in this technique, so we can see how that will sit perfectly over our anchor. We'll now use the 0.9mm FiberLoop to whipstitch our graft. And we'll simply stop exactly at our purple mark so we get the perfect tension. So at this stage, you can see I've come all the way to my purple mark and I'll do a locking pass by backtracking a millimeter or so, passing the needle there so there's no slippage. I can then cut off the needle from my FiberLoop, and we're ready to load this into the anchor. So if you see I have two free ends, and at the anchor level I have two passing mechanisms, one here, one here, that will allow us to pass each of those limbs. So you'll want to pass about 3 to 4in of suture and cinch it down. And then you can pull this through the anchor. We'll then do the same thing with our other end. We'll get ourselves all lined up. So we'll have our graft sitting in the appropriate position. And we can reciprocally tension each of these sutures until the graft is firmly seated against the anchor. Tie these two sutures to each other with the simple surgeon's knot. We can cut our tails. And just like on our first anchor, you do see that we have some excess length that can be removed. And that completes our all onlay mpfl reconstruction. At this point, we can either use free sutures or our existing sutures with needles from our hybrid anchor to repair the retinacular tissue such that they are brought over top of the graft, essentially making the graft to disappear. It's nice to do somewhat of an imbrication of this layer to reinforce that medial reconstruction. So if this was the original tension of those medial tissues, I can simply advance them by 8 to 10mm with my repair to reinforce my reconstruction. At this point, there's two options for closing the retinacular layers. You can either use a free suture, or you can use the sutures that are integrated into your patellar anchor. And I'll demonstrate both of those for you. If we're going to use a free suture, it's helpful to use this new double armed SutureTape that will allow us to do a pance over vast imbrication of that retinaculum very easily. It will be important to incorporate both layers one and layers two in our closure. So here I've grabbed both of them. It's also important to take a bite relatively distant from the free edge. The farther my bite is from the edge, the more imbrication we will attain. So my first bite will go through layers one and two, and with that same suture. I will then capture the periosteum on the anterior patella. This is typically robust tissue that holds suture very nicely. I can then grab the other suture end and create a mattress type construct. Again incorporating both layers one and two. And for our final bite taking a healthy portion of this patellar periosteum. You can see as I tension these sutures, how that will pucker up the medial tissues and advance them onto the patella. I can then simply tie these two suture limbs to each other. Creating a nice imbricated medial retinaculum. It is then easy if you choose to take an absorbable suture and run this more superficial layer. Closed. To fully complete that. Imbrication incorporated suture tapes with needles that came from our hybrid FiberTak anchor. What's important to remember here is that these are not sitting at the anterior edge of the patella, but rather at the midpoint of the patella. So if I put these stitches right through the free edge, I will actually be under tensioning the medial layer. And so just like on our first bite, we want to come quite far with our needle pass to make sure that we get appropriate imbrication of the tissues. The amount of imbrication again is directly correlated to this distance shown here. We can complete our second mattress stitch adjacent to our first. Remove the needles for safety of time. And at this point tie our medial retinaculum down to the patella. You'll notice that with these two different techniques. The knots end up at different locations. If you use the hybrid anchor, your knot ends up down here. If you use a free suture, you're not will end up on the patellar side. I do encourage you at this point to use just an absorbable suture to close this final layer to avoid any egress of joint fluid. The final step at the epicondyle side is to take our fascia that we've previously incised, and simply bring that over top of the graft. Once again making that graft sub fascial closure of this fascia can be done with any suture of your choice at that point. That completes the all on Mpfl reconstruction after standard skin closure. Before closing the fascia, it will be important to cut the excess suture length from your double knotless FiberTak and then simple skin closure is performed on both incisions.

Asheesh Bedi, MD (Chicago, IL), demonstrates an all-onlay MPFL reconstruction using Hybrid Knotless Knee FiberTak® anchors.&nbsp;

All-Onlay MPFL Using Hybrid Knotless Knee FiberTak® Anchors

I'm Asheesh Bedi from northern Chicago and have the pleasure today to speak a little bit about our approach for mpfl reconstruction, for recurrent patellar instability. Everything that you see here is the kit that you need to perform an mpfl reconstruction using these Knotless FiberTaks. I've really preferred this approach for lots of reasons. It's minimally invasive and minimizes the risk of patella fracture with small, secure anchors on the patella. And the Knotless technology has made fixation very facile there. As you can see here. All that you need is the working drill guide. This is a pistol grip guide that's designed specifically for the knee, with a short working length that keeps you in close proximity to the patella, with a crown tip that securely captures the location for your drilling. You can see we have the positive stop drill there for delivery, but also a 2.4mm pin, which is compatible with this guide if you want to use a cannulated technique, as we'll show shortly on the femoral side. These are the are the anchors. There's 32. six millimeter knotless anchors. What's nice here is the knotless mechanism is already pre converted, which allows for a zip tie kind of mechanism to secure the graft in an Onley fashion, to the patella and the femur. Their hybrid anchors though. So they also have 1.3mm tape with a swedge needle that allows you to augment the fixation with the traditional technique to suture. In this case, I'll demonstrate some value for me of those anchors with imbrication of the medial retinaculum and VMO on top of the repair. We have a right knee plan is again for an mpfl reconstruction. You can see we've marked out the borders of our patella here. I typically make a small incision along the superior medial border of the patella. I do think it's important to visualize here. So you know the boundaries of the VMO and can see your medial retinaculum, which can be an additional benefit of this procedure to perform a little imbrication or VMO advancement. We have a small incision just marking the general location of where we'll make an approach ultimately for our femoral fixation at Chatel's point. Thinner patients like this one here you can actually palpate the medial epicondyle adductor tubercle. And generally speaking if you connect the dots there that'll give you the right zip code for the location. It's perfectly acceptable to actually make an incision more horizontal between the two. But it's been my preference to work between two counter incisions as shown here. So we'll go ahead and start a little bit on the patellar side of the dissection. This is often easiest made more in relative extension. Again just to review. It's important to remember that the mpfl in its location lives there between layer one and layer two of the knee. And so we want to preserve that deeper capsule. But we do want to get into a safe plane to fully, directly visualize that we're on the medial border of the patella, and that we've created a nice bridge and footprint for healing of our graft. So just to briefly demonstrate this anatomy, you can see here we've come down to our knee. If we come a little bit this direction, you can see we're just starting to see this corner of the VMO that's helpful to notice and to observe that location. Typically, our mpfl graft is going to run right parallel along the inferior border of that VMO. Here we've just gently elevated the Bursa off of the patella. So we know right in this location here along the superomedial corner will be the location of our mpfl insertion. So we're going to dissect through this layer but preserve the underlying capsule. As you can see here, now that we've approached this superomedial border of the patella, I've started to peel here this medial retinaculum right off of the edge of the superomedial corner at the mpfl footprint. Here it's important to preserve, as you can see, this deeper layer of the capsule which we've preserved and is intact, but we've exposed and with the knife I've just scraped to expose right down to periosteum, this insertion and footprint of the mpfl. This is a great exposure. So we now have our landmarks of where we can place both of our anchors to reconstitute that broad footprint. It's often nice to prepare the bone here in between. You can either use a curette or a rasp or a round bur. We're now ready to go ahead and place our fixation on the patellar side. As you can see here, we can mark two locations for putting in our knee. Fibertak anchors. And all of this area that we've marked here will all be part of our broad footprint for our reattachment of the graft, right to the anatomic footprint of the mpfl. You can see it's rather broad and even larger than a centimeter even in this small knee. With that exposure, we're now ready to go ahead and place our knee FiberTak anchors for patellar sided fixation. This is the working pistol grip guide here. The advantage of this is this short working length. The crown tip will get good purchase right into the inferior portion of our footprint. You stay relatively perpendicular between the cortices here. A little bit of resistance on the lateral side of the patella helps to maintain our position. With that in place, we can simply advance the anchor down the guide. It's important to remain collinear. And then we'll simply impact that down. There's a positive stop when the anchor handle bottoms down on the bottom of the guide. We're now ready to go ahead and remove the anchor. You can pull this tab here. We can push this forward. This has the needle with the swedge on SutureTape. And then we can simply remove the anchor. Now that the anchor is in place, we can simply pull a little bit on these black swedge on stitches. That helps to set the anchor. This is now expanding just deep to that cortex. And we can feel that nice secure fixation even in this cadaveric osteoporotic bone. This is the loop of the knotless anchor. Here's the tail. It comes with a retaining white stitch to keep that loop patent. It's important given that this is already pre-constructed, that you don't pull too much on this. As you can see, as I pull on that, it'll actually shorten down your loop. You want to maintain that open to pass your graph later after both anchors are secure and fixed. We're now at the superior margin of our footprint, placing our second anchor. Same technique. The guide keeps us nice and secure. Gentle light taps will keep you right in line with your guide and help you to stabilize your patella as it's deployed. With a similar technique here, we'll get our black tape stitches and gently pull back to make sure we have secure fixation on the patella. We can also remove this retaining stitch from this loop as well. Next, we'll turn our attention to the distal medial femur here. It is perfectly fine to do this percutaneously under fluoroscopy to identify shadows point. I have often found that a small incision here centered between the adductor tubercle and the medial epicondyle, can actually help us to dissect the soft tissues and be a little more gentle in our fixation. So we'll start with an incision here centered over the epicondyle and the adductor tubercle. In general, your dissection wants to continue in those safe planes, keeping the VMO anterior to you. If you're seeing any VMO fibers, your two anterior with your dissection. As we dissect down here, I think you can see we're staying just along the posterior border. Vmo is anterior to us. This is at the level of the septum. This is the plane that you want to be in to identify the origin of the mpfl, which is going to be sitting here slightly distal to the adductor tubercle. So this is the point where we can dissect this soft tissue and now confirm our location for shadows point on AP and lateral fluoro. Based on our fluoroscopic views we've identified shadows point. This is confirmed anatomically here where we're just distal to the to the adductor tubercle. You can see our VMO anterior to us. I've deliberately prepared and scraped the periosteum here to create a nice interface for healing, for the origin of our mpfl graft. What's nice here is we've placed this pin in the conventional technique that we would, at chattels, point no different than if we were doing a conventional socket based fixation. But we can use our working pistol guide compatible with this pin to place our anchor. So a nice technique as shown here is. We'll now take our guide, and we can simply slide this over the top of our pin. And we can exchange out the pin. Now for our anchor. You can see it nicely follows that track. And we're nicely secure and ready for Onlay fixation now on the femoral side as well. Now that we have all of our anchors set, we need to create the conduit plane between our incisions. I've gently tunneled this snap or tonsil between layer one and layer two just at that portion along the inferior border of the VMO. We can now grab a FiberSnare such as this and pass that through between those planes. We've dilated that and this sets us up for success. Now to simply shuttle our graph from the patellar side in the right plane to our femoral incision for Definitiv fixation. So now we're ready to bring the graft onto the field. What I like about this is we've minimized the time. The graft is on the field, and we've set up everything for seeding and shuttling the graft. This can be an autograft or allograft. A gracilis autograft like this or another allograft is perfectly reasonable. If you notice, I've made this purple mark at the half way point. I find this to be helpful because if we center that mark between our two anchors on the patellar side, we know that we've placed this graft right at the midline position to keep equal tails for fixation on the femoral side. In this case, we've whip stitched both corners of the graft. Believe it or not, with this technology you actually don't have to whip stitch it. It just makes it easier for shuttling. So now we're ready to go ahead and pass one tail of the graph through these precinct loops in our patellar anchors. As we mentioned earlier here, we'll now bring this graph right through these loops. We nicely have the graph positioned in line with our footprint. We've marked our center part between the fixation points. And this becomes relatively simple where at the same time now we can simply tension and bring our graph right down opposed against the footprint. And we're firmly fixed opposing that graft and tensioning it right against our prepared footprint on the superomedial patella. Now, what I like very much here is we have these additional swaged sutures attached to the anchor. This will allow me, after the procedure, to not only incorporate some of the graft, but to re-advance what's hiding here, the VMO and the retinaculum over the top of our repair, achieving an additional Imbrication and VMO advancement for further stability and biologic augmentation. Now that we're fixed on the patellar side, we can shift our attention to shuttling the graft and focusing on the femoral side of fixation. That's the advantage of previously placing the FiberSnare. Here. We can simply pass through, grab the stitches that have been placed in our graft. And that now puts us in the position to go ahead and shuttle these through using the snare. We can pull the graft here. And now we're shifted to focus our attention on the femoral side of fixation. We can look at the reference point relative to where we've placed the anchor at Chatel's point. What's nice here is in our position in which we expect to tension the mpfl, I can bring my graft right up adjacent to the anchor location. We can even mark the graft at that location, as we have a general reference point to know where we expect that graft graph to seat under appropriate tension. There's certainly multiple ways to use this anchor. One is to now take the swage stitches and to whip stitch and use a tension slide technique for fixation. But what I have found to be very useful is to simply now use the knotless mechanism to secure the graft in this location, and use the swedge on SutureTape to further augment the fixation and secure the graft. This is very convenient because it doesn't require any trimming or preparation of the graft, and always has the length match at the anatomic origin point at shadwell's location. We now have the loop of the knotless mechanism. I'm going to pull the sutures of our graft through that loop. And that will pull our graft inside of that knotless loop here. And in a very simple way, I can lay down the graft and bring the loop down again with the marking on the graft providing an Providing an additional check that we're securing that at the expected location. As I tighten that, that secures the graft anatomically at Shadows Point, we're already nicely fixed with the knotless mechanism right at Shadows Point. But we have these additional suture tapes wedged on a needle here that we can use to augment the fixation and secure the repair. So working just slightly distal to that fixation point, we'll start to place a little bit of a locking stitch into our graft. I'll try to grab both limbs of the graft. Once we have good purchase we'll begin to work our way back. We now have the other end of the suture tape with a swedge. We can pass this a single time through the graft, which will allow us to tie a mattress suture over the top of our graft. The end result is an additional suture augmented and tied tension slide repair with the knotless mechanism setting the ideal length and tension. We have still retained the stitch from our knotless construct, so if there's any desire for additional tensioning and to confirm we're secure, that can be performed at this time. We're now in a position to simply trim the excess graft, and we have an excellent onlay based fixation on the femoral and tibial side, with excellent tension in our mpfl graft. This is our end result, securely fixed at the marked point, at Shadows point, with additional augmentation of fixation distally with a running tension slide and our knotless mechanism. We've checked the tension in our graft, which is appropriate at 35 or 40 degrees of flexion with the patella engaged in the trochlea. We've confirmed approximately two quadrants of symmetric glide. You can see here. We also can confirm excellent position of the graft running along the inferior border of VMO in between layer one and two of the knee. Here at this point, we take advantage of the additional features of these anchors. As we've now visualized the graph, we can move one layer more superficial, and that allows us to visualize directly this layer of the retinaculum and the associated VMO. This can now be brought over the top of the repair to advance and to close our small area for exposure for the patellar footprint. We're now set to go ahead and repair this retinaculum and VMO over the top of our arthrotomy. These double swaged stitches allow for an excellent mattress repair. I'm deliberately taking a slightly larger bite to allow for that advancement. You can titrate your advancement based on the severity of instability and your concern after your mpfl reconstruction. We can now complete that mattress repair, starting with the inferior anchor. You can see I can approximate right to the edge of the VMO. Again, deliberately over advancing over the top of the repair. I have found it helpful to place the sutures for both anchors before tying, so we don't close our access for the superior anchor. We've now passed both our pairs of stitches for two mattress stitches through the medial retinaculum and the proximal VMO. With those in place, we can now tie these mattress stitches. This closes our small rent for patellar exposure, and also achieves an imbrication and small anchor based VMO advancement, which is an additional advantage of these anchors for Mpfl reconstruction. We've fully closed our exposure with the Mpfl graft nicely placed between layer one and layer two of the knee, and our Mpfl reconstruction is complete, and now we're simply ready for wound closure.

Gautam P. Yagnik, MD (Miami, FL), demonstrates an onlay MPFL reconstruction using Knee FiberTak® hybrid anchors in the patella and a FastThread™ interference screw on the femur.&nbsp;

Onlay MPFL Using Knee FiberTak® Hybrid Anchors

Hi, this is Gautham Yagnik from Miami, Florida. Today I'm going to demonstrate the Mpfl inlay reconstruction technique. Before we get into our procedure, we're going to highlight some of the instrumentation and implants that we're going to be using. We're going to use the new knee FiberTak hybrid anchors that have both a knotless mechanism as well as free sutures. We also have our drill guide and our 2.6mm drill. We'll also use our mini SutureTape FiberLoop as well as FiberSnare. We'll also be using a six millimeter FastThread interference screw. We have our nitinol wire, our template to help identify shadows point on the medial side of the femur, our beef pin and reamer. The first thing I'll do is expose the medial border of the patella. So you can kind of translate the patella slightly medially here. And you can see we've drawn out our incision. So I'll take a take a blade and we'll cut right down through the skin and soft tissues. Subcutaneous tissues, right down onto the patella. And then you can see now that we've, we've gotten down to the, to the retinaculum here that lays over top of the patella. So now at this point we'll incise sharply right on the medial border of the patella through this retinaculum. So once we've exposed the medial border of the patella here we've incised the retinaculum. And we're looking right now at that upper one half of the patella, the medial border here. For the next part of the procedure, we'll go ahead and place our FiberTak anchors prior to placing our anchors. We like to create a bone trough on the medial side of the patella. We'll use our Miss Burr here to create a nice bleeding bed surface to facilitate tendon and bone healing. So now we're going to go ahead and prep the medial side of the patella here. [00:01:58] Create a nice trough. So we've created our our trough here for our graft. We now have our medial border exposed. We're going to go ahead and place our first anchor. So after we prepared the medial side of the patella the medial border of the patella, we're going to place our first anchor proximally. So bring our guide down. [00:02:25] And we're going to drill. And then we like to bring this drill in and out at least a second time here just to make sure we can fully seat our anchor. Then I'll hold the guide in place and we'll place our anchor right through the guide. Bring it down until it's contacting bone and then with firm counter pressure will mount this into place. So after we've we removed our anchor inserter, we can see the different sutures that we have here. We have our black suture tapes that are sliding sutures that will also help us to set the anchor. And so these are preloaded here with with needles to help us for our retinacular repair invocation at the end of the procedure. And then we'll place these to the side. Then you can see our SutureTape loop that we already have that's pre converted for our knotless mechanism. And so we'll leave this nice and long now. So we put these sutures off to the side. And we'll place our second anchor anywhere between 10 and 15mm distal to where we placed our first anchor. We'll go ahead here and place our second anchor. So we'll bring our drill in. Once again we're holding firm counter pressure. We're going to go and cycle that drill. Bring it all the way down and down again just to make sure. That's good. Bring that out. And then again, through the drill guide, we'll place our second anchor again. You need someone to your assistant to really hold firm counter pressure here. We've removed the inserter. And once again, we can use our our free sutures here to kind of toggle and seat our anchor. Make sure that it's firmly seated within the patella. We'll move these sutures out of the way. And once again we have our loop that's already pre converted for our knotless mechanism. And again we're not going to tension these down too much. But I will give a little pull here just to make sure that this slides well. So we know we have both for our anchors seated. We have both of our knotless mechanisms that are pre converted ready to go to accept our graft. So now we're bringing our graft onto the field. You can either use autograft or allograft gracilis or semitendinosus. Just depends on the size of the patient. The nice part about this procedure is there's really no graft prep that's needed. I'll measure the graft to approximately 220mm. So now we'll go ahead and slide this graph through the pre converted knotless mechanisms. And then we use our center mark as the position that we're going to place our graft against the patella. We've laid our graft against the medial border of the patella. We put our mark between the two anchors. And then we'll go ahead and fix the proximal portion of the graft first. So I'll go ahead and start to tension that down. And you can see how easily that goes. And the SutureTape really compresses and secures that graft to the medial side of the patella very nicely. So once I do that and I'm happy with that position, I'll go to my distal anchor. And I'll repeat this same step here. And once again just taking this tension out and locking this graft, securing it really nicely to the medial border of the patella. And then I can go back and get any little extra bit of creep out of this system and really make sure that this graft is really firmly secured to the medial border of the patella. Once we finish that aspect of it, we can bring our graft over and we can see that we have at least about 10 to 15mm of graft that are approximated against the medial border of the patella. And just by adding some gentle medial pressure to our graph, you can see how much control we have over the whole patella. So it's a really, really nice way to fix your graft. So now we're going to sew the two ends of our graft tales together using this new mini SutureTape FiberLoop. So pierce the graft in the center to get it started here. Going to lock our first limb in here, bring it back through. And for our last loop. We'll try to lock it here just so we have this really well secured. So now we have both tails sutured together. We have our graft fixed on the medial border of the patella. And so we're ready to move to the femur. So to identify our femoral fixation point we'll use fluoroscopy. We'll get a perfect lateral and we'll identify shadows point on the medial side of the femur. Here you can see on the fluoroscope image us identifying this isometric point. So once we've identified shadows point on the medial side of the femur which is just slightly proximal and a little posterior to the medial epicondyle. So between the medial epicondyle and the adductor tubercle is the point that we've identified on fluoroscopy. So we made our incision. We dissected down. We're going to go ahead and place our pin. Pen. So field, make sure I'm in that right spot and then we'll go ahead. And you want to angle your hand slightly proximal and anterior to avoid the notch. So we like to keep the knee at this point in 30 degrees of flexion. We've placed our pin. And now we're going to Overeem with our six millimeter reamer. And then I'll usually take this all the way to the far cortex but not through the far cortex. Just so we have as much tunnel length as possible so we don't bottom out on our graft. So once we've done that, we'll go ahead and put in a nitinol wire parallel to our our beef pin. That way we know exactly where our tunnel is. And then we'll go ahead and pass our graft from the patella down to the medial side of the femur. So I like to use a curved Kelly here through our little path that we created. We're staying extra articular but deep to the soft tissues. You can see our Kelly coming down through. And this is where we'll bring our FiberSnare onto the field. Pinch that and we'll bring that back up to the patella. We'll use our FiberSnare here to take the tail ends of our patella. Graft. And we're going to shuttle that down to the medial side to our tunnel. So once we've brought that down again holding a little bit of counter pressure on our graft, bringing our sutures down first. So that way we make sure that there's no soft tissue bridge. And you can see we can bring our graft right parallel to our, our beef pen. So now we have our graft tales loaded into the beef pen. And now we're going to go ahead and pass those into our tunnel. And I'll use a freer here just to keep a little counter pressure on the graft. And until we're ready to dock it into the tunnel. And so then we'll go ahead and position the graft right at the opening of the tunnel. And then we'll dock that graft into our tunnel. And you can see that. So now we need to set the tension for our graft. The one thing we want to avoid here when we're doing an mpfl reconstruction is over medicalizing the patella or over constraining the patella. So now that we've passed our graph, we have our guidewire in place for our screw. We're now going to go ahead and set the position of the patella. So we'll place the knee in 30 degrees of flexion. And then kind of translate the patella until I feel that perfectly centered position where I line up the lateral border of the patella with the lateral aspect of the trochlear groove. And that's where I'm going to set the patella. I'm going to have my assistant hold a little pressure and set the kneecap. Hold it right in that position. And he's actually placing a slightly laterally directed force so we So we don't over idealize or over constrain the patella. And we have some tension on our sutures. So we're going to bring in our FastThread screw now over top of of our nitinol wire. And now that we have everything set in position, we're going to go ahead and fix our graft in place. And the nice thing about this screw is you don't need to tap and fixate our graft. So I'll go down and put my finger until I feel that our screw is completely flush and buried within our tunnel. Go ahead and remove our screw and our nitinol wire, and we can go ahead and range the knee to make sure that we're happy with the position of our of our patella, so we can see that the graft is now well fixed on the patella. We have nice tension on our graft. We have an over constrained or over medium size our patella, because the mpfl is really just a check rein to prevent lateral subluxation or translation of our patella. And then here we can see that the graft is well fixed in the femoral tunnel as well. So we can use all our sutures from our knee FiberTaks to help close our retinaculum. So we use a free needle here with our repair strand or our tensioning strand. We can go ahead and pass that through the retinaculum. And for this I'll do a horizontal mattress using these sutures. So we'll pass this through and then we'll load. The proximal suture. Do the same thing here with our proximal suture. So now we have a horizontal mattress stitch that we can use. We use our sutures from the distal anchor to close our distal retinaculum in a simple fashion. And then we can go ahead and use our sutures from our proximal anchor to close the proximal aspect. So now we've passed all our sutures. So we have our proximal sutures passed on either side of the retinaculum up here. You can see how nicely that will approximate the tissues. We have our distal sutures passed here. And we're going to tie our horizontal mattress using our tensioning sutures. So I'll go ahead and tie that and we'll go proximal to distal. And you can use these sutures. Additionally if you have some redundant capsule or some redundant tissue if you want to imbricate some of the tissue. And so you can see that we get a really nice closure of the soft tissues over top of our mpfl reconstruction.

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MPFL Reconstruction With Knee FiberTak® Anchors and a BioComposite FastThread™ Interference Screw

MPFL Reconstruction

Child (D)

Patients with patellar instability suffer from recurrent patellar dislocations and are limited in their performance of activities of daily life.
In order to create congruent bony anatomy, the sulcus deepening trochleoplasty procedure helps patients get back to daily living activities.
Deepening trochleoplasty demands precise surgical skills and customized technical solutions for each individual patient and indication. The new Arthrex Trochlea Guide System enhances reproducible cartilage preparation, with 3 mm and 5 mm Offset Aiming Guides and effective, solid bone modelation with the dedicated 2.9 mm Burr. In conjunction with Arthrex PushLock® or SwiveLock® anchor fixations, this technique offers a solution for an anatomic trochlea recreation.
Please note that certain bio (PLLA) anchors and screws are not available for sale in EMEA.

Trochleoplasty for Patellar Instability Due to Trochlea Dysplasia

So this is a 20 year old female. As you can see, she's had prior mpfl repair surgery. She's had ongoing instability for years. Never a trauma. Her kneecap just started dislocating rather traumatically. Here she is in full extension. And I can completely dislocate her off to the side there. You can see her pop back in right there. Now, if I flex her up about 30 degrees, I can hold her off. And you can see that I can keep her kneecap. Just stays dislocated right there. And then it kind of violently pops back in. And now I have her up here probably about 45 degrees. And same thing. I can just slide it right off to the side and this will just stay out. So I kind of have to gently put this back in here. So there's the lateral border. Her superior patella is about there. And here's your inferior patella. So I'm actually going to make this incision a little bit medial of her lateral patella. Because we expect once we shift her immediately with the mpfl reconstruction that her patella is going to sit over here. And I like to use this triangle for the bulk of the case. It puts these lateral structures on stretch. And then it actually helps to do the trochlea plasty with a little bit of knee flexion. And then obviously for the Mpfl reconstruction we like to secure that in knee flexion as well. So the first thing we'll do is we're going to come down to the lateral retinaculum. And we're going to do a z lengthening of this. And the beautiful one of the beautiful things about this lateral approach is that you can do this lengthening as an inherent part of the lateral knee arthrotomy. So we'll we'll do the z lengthening at the beginning and then we'll close it on our way out. You can see that's like the the the lateral retinaculum proper right there. So you've got these really nice fibers kind of coming down here and all this other stuff in it. It all gets lengthened as well. But this is like the meat of the fibers right here. And you can see it's sort of like there's the inferior pole and there's the superior pole. It's kind of like mid-level on the, on the patella laterally. You know, I can incise it down here. And that's going to give me two, 2.5cm of, of potential length. And we find that we get at least a centimeter and a half on most these people. So we really we really do go for distance on this. There's the deep layer there and then there's the synovium there. So that's the deep layer of the retinaculum. And then here's the synovium. And you have to cut through the synovium. So we'll cut through that. Next. The layers kind of merge up here. And then I can take this up into the quad. And I'll usually do this with the bovie. And I can usually get my finger in here like this. And I can feel the inner surface of the patella. And I can just kind of just run that. I'll use the cut function. You can see that I can get this, this quad split. Well proximal. I mean that's probably five centimeters of quad split there. So that's great. So then we put this k wire in as a retractor to kind of help hold the patella. Immediately you can see we've got pretty excellent exposure of the entire trochlea. Now I've kind of just marked where I'm going to provisionally start making my cut. What I'll do is I'm going to make these dots. I'm going to just kind of map out where I want my new groove to go. Her current groove kind of goes like this. This is how we change her tibial tubercle to trochlear groove distance. We're going to move it from here to here. We're going to lateralize her trochlea about a centimeter. So whatever her TG is now, we're going to take that down by a full centimeter. So even if she's like 25 we'll take her down to 15. If you're going to consider a bony procedure for patellar instability, I think this is the one that we should be thinking of at least first because it addresses not only the the congruency between the groove, the trochlear groove, and the patella, but it also addresses its relationship to the tibial tubercle. So my thought is I'll probably bring it to the cut to about here. And so I'll just kind of mark that out. Like that. And then what we'll do is we'll bring our we'll elevate the flap down to about there. And that should give us plenty of space to elevate the flap and, and and remove the bone underneath. So I've marked there I'm going to take the cut. I'll start the flap elevation a little bit distal to it. And sometimes in these right through here where I'm making this, this turn, I kind of will use this, The skinnier osteotomy. I've kind of I've been liking that. It allows me to kind of contour it a little bit better. And then I can switch to the bigger one. And we kind of use the curve to our advantage. And then we'll kind of take it up around the horn here. So this is a standard ACL guide here. But this is specially designed for the Trochlea Plasty set. This goes all the way in to the handle and you tighten it. And you can see this has a little sort of smooth surface to it. Metal surface here. And this one is marked five. And what it means is when you stick this through here there's five millimeters between the burr and the top of this. So you can kind of gauge what your clearance is, and the plastic sheath centralizes the burr in here so that you're so that it doesn't wiggle around and become inaccurate. And then also when you're doing some final touches, you can actually take this off and you can hold it like this. And that way you can you can put your hand right here for greater control. And the and the burr isn't like spinning your glove up on you. So we've already kind of started the cut with the osteotomy. So now I'm going to keep firm pressure. And the way that I'll do it is if, if I'm going to air one way, I'll air like this a little bit, because that way I know I'm not going to do this and then sort of come through the cartilage up here. Then this should get in here fairly easily. Yeah. And that goes in nice just like that. And I'll take it to the depth. And then the move is this. It's it's it's kind of like you kind of taking it back and forth in a V. So you're kind of pivoting off the apex of the burr like this, back and forth, back and forth. And I know that my BR is basically at the tip of this of this metal guide right here. So I know what my depth is. I think there's just a little bit more down through here. But that's starting to come. See that? So you can see we're already starting to get this thing to elevate. I usually just take this kind of slow. Just kind of gradually let the cartilage get used to getting picked up. But you can see just bit by bit, it really lifts up nicely. Now we've got enough room here that we can actually kind of get a retractor underneath and hold this flap up like that, and then I can come in and I can start removing bone from underneath this. We're going to start removing bone through here. We'll do We'll do some macro cuts first and then we'll smooth it out. Okay. And what we're doing is we're basically taking the osteotomy. And I'm creating like the depth of the groove, the center point of the groove here. And then what I'm going to do is I can once I've made this bony cut this way I can connect it with the osteotomy this way, and it puts my groove exactly where I want it to go right here. So that's sort of a little helpful trick as far as setting up your groove. And then, you know, you're not having to guess as to where it goes later in general. Or I'm deepening this about a centimeter and I'll really try to and I'm really going to preserve this, this lateral wall. You can see I can cut in to this. And then we're going to save this bone graft. And we can kind of just remove these wedges of bone like this. There's our bump right here. And so we're going to be able to get whack that thing out right now. And then down this way a little bit more. There's the top right there. And there's the base of it. So that's actually a little over a centimeter of bone that we've resected right here. And again this was all confluent with the with the lateral wall. And now we've taken it down a good centimeter. We have to remove some of this medial stuff here. But the most important aspect is this right here we want to reestablish a you know, the lateral trochlear inclination of probably close to 20 degrees or so is a pretty safe bet. I've done the macro now. And now I can go to micro, and I can kind of smooth this out a little bit with this bur. And it's nice because again, this cartilage just gets a little bit more and more flexible as time goes on. Sometimes I'll just take this and I'll come underneath the flap with this and just create a little stress riser right underneath. I might just come underneath here a little bit and just just remove a little bit more bone. So we're actually getting a pretty good mold here already. The contour is really well maintained here. And it just there's really no speed bump or anything on this. This is really looking nice. And her bump is completely gone here. This is three strands of number one vicryl. Okay. And what we're going to do is we're going to make a total of 12 strands here. So here we have our PushLock and we've got now six and six strands. And this will be so a total of 12. And we're going to use this as our center PushLock for fixation of this osteochondral flap so we can bring this up. The flap that we elevated ends about right here. So I'm going to put this just inside. Just right there, not below it, because I'm not going to get as good a compression on the flap if I come just below where the flap was. I'm going to come just inside of it right here, right in the depth of the groove. And this is where we'll put our first PushLock. Yeah. Okay. Okay. Yep. Yep. Good. And several spins until it pulls out. So I'm going to pick four strands, which just sort of seem to want to come up on the superior aspect of Speak to this. And now you know what we've been doing lately. To really help us get a groove is we'll put one instead of just bringing the next one all the way up to the top up here. We'll actually put one about midway about right here. And that really helps us sync it down nicely there. Okay. Okay. And then we'll put one more. Yeah. Right up here like this. And then I'm going to take that about right right there. Okay. So we've got our centerpiece and we've got a really beautiful groove that that we've established here for her now. And now we're just going to add a couple Extra PushLock here for for a little bit of added fixation. We'll put one laterally and then we'll put one medially. Looks really good. Nice. Nice central deep groove here. We can cut the sutures. And then what we can do is we can kind of see how this thing tracks. And again this fixation here with these with these this suture and PushLock construct. It's it's just so robust. We let these people range right away and weight bear right away. The more that they bend their patella, it compresses the patella against this osteochondral flap and helps it heal. And in however many years this procedure has been performed, there has never been a case of case of the osteochondral flap not healing back in place. So it's an extremely reliable thing. I mean, her kneecap already is starting to feel more stable. I mean, obviously I can still push it out because we have to do the mpfl, but it really it's you can already feel it catching on the lateral wall here. So I haven't even done the Mpfl reconstruction already. The stability is significantly improved. So here's the superficial retinaculum. It was here. So it went from here to here. But you can see we've got this lateral portion completely closed. So we don't have to worry about iatrogenic medial instability. We don't have to worry about pain that you can sometimes get from an unhealed lateral release. So this lateral lengthening has been a very very valuable tool and a big improvement in dealing with the lateral side of the patellofemoral joint and patellar instability.

Philip Schöttle, MD, PhD, (Munich, Germany) demonstrates an innovative trochleoplasty technique for chronic patellar instability. He utilizes the new Arthrex® trochleoplasty instrumentation designed to safely and reproducibly fold back the cartilage layer using a marking hook and burr. The trochlea is then shaped to a more natural curve. The cartilage is reattached using PushLock® or SwiveLock® suture anchors and resorbable sutures.

Deepening Trochleoplasty

The indication for here performed trochlea. Plasty is a chronic born habitual patellar dislocation, as you can see in this young lady who has a positive apprehension and an ongoing patellar dislocation, up to 30 degrees of flexion and more. The instrumentation has a special burr, the handpiece, and two distance hooks with either three, as you can see here, or five millimeters of distance for later detached. The cartilage indication is given by the MRI, where we see a flat or convex trochlea, and the clinical finding of this ongoing patellar dislocation towards lateral, which is difficult or hard, sometimes not possible to keep central by hand. I prefer to use a lateral arthrotomy, due to the fact that I have the chance to a make a lateral lengthening of the double layers of the lateral retinaculum as well as you will see later. To start, BioTrochlea plasty from the proximal lateral part of the bone for the lateral lengthening. After preparing the lateral retinaculum, the superior layer is incised by a 15 millimeter scalpel. And then prepared two words posterior without injuring the deeper layer. Once a certain distance has been prepared at the posterior part, the deeper layer is incised. What you see here, and this is the distance I gain for a later lengthening. In closing, after the arthrotomy has been performed, a human hook is brought to the medial side and I use K-wires to have a better view in this up to five centimeters big incision. Unless I see the complete proximal trochlea where the groove is missing in this patient, a drastic bump can be seen. So every time the patella goes from extension into flexion mode, it's getting into this bump and starts to dislocate even more. No trochlear groove can be identified and has to be created. First you start with the incision of the period, also using a scalpel all the way all around the trochlea. Once this has performed, you either can use chisels or palpation hooks or Rogers to mobilize the periosteum, and then using a straight or curved chisel to lift up the proximal lateral three millimeters of the cartilage from the bone. Make sure that you go all the way towards medial before you start using the Arthrex special lipoplasty bur with the five millimeter distance for further detaching the cartilage flap from its bony underground, make sure that while performing the reaming, you bring all the pressure on the palpation hook which is guiding the bur and not the other way around to make sure you are not injuring the cartilage. Furthermore, choose the direction of your twist and turn so in case you would miss something, you would guide it towards proximal to create this very movable nice cartilage flap with still enough bone at the back side, you can use the three millimeter distance bur in a second step to have enough bone for the cartilage to heal, but still you can mobilize it and mold it easily in the now created groove. Therefore, different chisels and washers are used to first create the new before not existing rim. Make sure that you also respect the before existing bump and diminish and make lower the lateral trochlea. For final shaping, you can use the same verb as before. You use the hand grip as a guiding tool and you do not need the distance hooks anymore. Once enough depth has been created and the trochlea seems anatomical for you, you gently and softly press the cartilage flap back into its new created groove. Therefore, you can use either fingers. You can use palpation hooks. You can also use special instruments. Just make sure that it's easy to replace it in the groove with the same burr at the distal end of the new created groove. We make the first hole for our PushLock, which gets, in this case, a vicryl tape into the distal end of the new bony groove. If you do not have vicryl tape, you also could use three two sutures. The second PushLock fixes the vicryl tape along the new created trochlear groove just at the proximal end. You recently created. Once this has been done, a third PushLock is used to readapt the lateral flap, which otherwise would look up like a butterfly in a triangular shape. In the next step, the periosteum can re-adapted using vicryl two zero sutures. All the way around. And for an additional closure, I like to use fibrin glue to limit and lower the subchondral bleeding after this surgery. As you can see here, by this procedure the bump has been eliminated completely. A new trochlear groove has been created, and you see the double contour of a medial and the lateral trochlea, which has not been existing before. Right now, the patella can glide into this new groove and has a guidance. Please tell your patients that due to the vicryl tape or the vicryl sutures for the time of six weeks until they dissolve. The patients will hear a slight crepitus from extension to flexion, which dissolve for sure when the sutures are resorbed. Foreclosing the before lengthening technique can now be used, if necessary, to add this lateral lengthening, in this case circa 1.5cm. The lateral arthrotomy should be closed in 70 degrees of flexion due to the biomechanical properties of these structures at the end. The full range of motion has to be tested, and you can see that right now the patella is guided safely in nearly all of these cases. To also provide stability in extension, please add an mpfl reconstruction.

One of the most frequent causes for patellofemoral dysfunction is habitual patella dislocation or subluxation. This technique guide shows one method of how to solve structural causes of patella instability by doing a deepening trochleoplasty.

Trochleoplasty - Indications and Methods

I want to introduce and explain to you a little bit about trochlear dysplasia. The combination with patellofemoral instability and the treatment by trochlear plasty. I think the biggest question is when do we really have to perform a trochlear plasty? And when is it enough to stabilize the patella by an mpfl? Only if you focus that, then the apprehension sign and the j sign is, for me, the most important examination to decide if I have to go to perform a plasty or not. If, for example, you see this little girl who has a positive J sign at 40 degrees of flexion, when all of a sudden the patella pops out to lateral, then I see the MRI with a missing groove and there is a convex trochlea. And in the moment the normally shaped patella. Tesla. Has no engagement and no guidance anymore and is flying out to natural. The indication for a trochlea plasty is given. Why? If I only would do an mpfl, then eventually I could keep the patella in a centralized place, but I would increase the pressure onto the convex trochlea with a patellar edge, and that would be like bringing two convex things onto each other. First of all, the pressure increases and second of all, it could not stay stable anymore. So and at that point, I see the indication clearly given. I'm often asked about early degeneration. Or try this after performing a trochlear plasty and the question about the cartilage viability. And since 2002, when I perform this trochlear plasty in the technique more or less the same as you see today, I have not seen any drastic changes into degeneration. Iteration. So we had to replace on the other side. I've seen a lot of patients in the late 20s and early 30s who should have had a trochlear plasty in the age of 1820. They have been treated with a transfer of the tuberosity or a lateral lengthening, and they're ending up in such an early degeneration that in rather those patients I then have to treat with a partial replacement in patients with a dysplastic trochlea you have to imagine this is like playing bowling on a convex bowling lane. And when you throw the bowling ball, it cannot hit any pin. Why? Because it will fall to the right or to the left, and a transfer of the tuberosity will not be the solution, at least not as an isolated procedure, because this is only changing the starting point, and it makes no difference. Coming back to the example with a bowling lane if you throw from here or from there because the lane stays convex and the ball will fall off. As an additional procedure for getting the starting point more centralized. After creating a groove, it may be, and sometimes it has to be a very helpful additional procedure. With these five millimeters distance reamer, I can detach the cartilage from the underlying bone so easily. The next step is thinning the cartilage flap from the underlying bone to make it more malleable. You also can add a three millimeters distance guide, and then you can thin out the bone behind the cartilage flap. So in the end, it's really easy to mold it in the closing of the lateral retinaculum, which I recommend to open in a z-plasty to eventually gain some soft tissue. Distance should be performed in 70 degrees of flexion, because in 70 degrees of flexion the tension of the lateral retinaculum is the highest in the whole range of motion of the knee. Once this is performed in all trochlear plastics, I recommend to perform an additional mpfl reconstruction. The reason, therefore, is that the trochlear plasty is influencing the patella from ten degrees in flexion onwards, but close to extension. Even a normal trochlea has no stability function without a working mpfl, which is in all cases gone after the first patellofemoral dislocation. So don't be afraid performing this procedure. It is not like a last point or a last decision procedure. It's something you also can offer as a first time procedure. And with these new reamers, it's such a safe and reproducible intervention.

Philip Schöttle, MD, (Munich, Germany) explains and classifies patellar instability and discusses MPFL reconstruction in detail. In patients with flat or convex trochleae, Dr. Schöttle shows how MPFL reconstruction is often not enough to provide adequate stability. For these patients, he shows how trochleoplasty can recreate a new groove in the trochlea, using a specially designed guide.

MPFL Reconstruction and Trochleoplasty Presentation

Thank you, ladies and gentlemen. Just before we talk about what to reconstruct and when to do, we should understand why a kneecap becomes unstable. The main medial restraint, a passive one, is the medial patellofemoral ligament. And it has the structures in between the proximal part of the medial patellar edge and the area later described around the adductor tubercle at the femur. We also know by biomechanical examination that it's the main stabilizer close to extension, taking over up to 90% of the medial restraint. And it's rupturing in 95% of the first time. Kneecap dislocations. Furthermore, when we move over as a mix up between passive and static stabilizers is when the patella should engage into the trochlear groove, because then, like in NASCAR racing, the kneecap is stabilized by by the lateral trochlear facet and additionally by the mpfl. But if the trochlea is not there, the patella starts to be unstable. And there we come up to the trochlear dysplasia, which means that there is no groove, but there is a flat or even convex trochlea, and this is, as described by the lion group by Henry du jour, has a prevalence of 84% in patients with a habitual or concomitant patellar dislocation. And it's not, as we initially thought, just a missing of the groove. It's a hypoplasia of the medial facet, which is then overgrown by the lateral one. And also from lion was the one who then made different classifications a 2D depending if you just have a flat or a convex, or even like a gate pattern, or a or a line like trochlear. As you see in D, it's a genetic defect. It's nothing what you get by an accident or just because the patella popped out, but it's only influencing the trochlear. So it may happen that the trochlear is flat or even convex, while the patella still has this typical V shape and it's not congruent. So still the instability works because you need or you try to balance an egg on a flat table or other static factors influencing patella stability are those who are moving the groove away from the patella tracking line, i.e. an internal rotation of the femur, bringing the trochlea more to the medial side. A valgus knee which Also guides the trochlea towards medial, while the insertion point of the patella and the tuberosity moves laterally as well in an external rotation of the tip of the tibia. How can I click on this video? Can we? Are now we go the touchpad? Okay, this is a great one. Instability in the MRI. We see a flat trochlea, a ruptured mpfl, and an unstable patella in between 0 and 45 degrees of flexion. This is a typical patient for reconstructing the mpfl. Here we see a patient what we call a grade two instability. Orthopedic surgeons, or at least me. I can count to three. So I made a three group classification. Two is a mix up of static and passive insufficiency. So here. Also the trochlear guidance is missing and therefore the patella cannot engage. And the patient only with a trick can get his knee or the kneecap stabilized. And then there are these drastic instabilities where you have an additional rotation malalignment. And the patella is guided chronically on the lateral condyle and never finding any way into the groove. This is then more or less pure static instability, a so-called or less. We call it a grade three instability. And for all of them, different ways to stabilize have to work. And the transfer of the tuberosity cannot help always and is initially taken as a as a tool to treat pain. And sure, you can visualize the patella, but you also have to take care, like in this patient who has been medicalized 15 years ago and was over medicalized and it created later a medial patellofemoral degeneration. In our place we say like these are like the tools we can use. That's for the instability close to extension. We have the mpfl reconstruction as a passive restraint. If there is a convex trochlea, we have to combine it with the trochlear plasty, since otherwise you really pull a convex patella onto a flat or convex trochlea, ending up in a degeneration an early one. And if you have these pure static chronic dislocations, you have to combine them with other osteotomies proximal or distal. Talking about the mpfl reconstruction nowadays is easy, but you can imagine or not. Eight years, ten years, 12 years ago when I started to make my first cases, everyone wants to do lateral releases and transfers of the Tuberosities. And thanks to Arthrex who believed. And this is a new way to go and make our lives more easy and the patients less miserable. We had the chance to install this new technique and so we created the Mpfl reconstruction, and it was the first one which was a double bundle reconstruction, which can help more than 80% in the instabilities are due to this aperture fixation I'm going to show you. We had a fast post-operative mobilization with an immediate full range of motion. We had no pain in kneeling since we did not touch the tuberosity, and we have seen over time, less post-operative complications while using the two bundles is because also Andrew I am, as it was who showed us that close to extension, the proximal fiber bundles are more under tension, while if you go in slight flexion around 40 degrees, it's the lower bundle who shows more stress. So therefore if we install we start the surgery with examination the patellofemoral instability. And you see up to 30 degrees it's easy to dislocate. But then when we come up to 45 it starts to stay stable. The kit we use from Arthrex is a very simple and slick, and by a small skin incision over the medial patellar edge, we can drill two guide wires. We over drill the four millimeter and then secure our three gracilis graft, which is absolutely more than enough to reconstruct. An mpfl is fixed at the patella with the two SwiveLock in smaller patients, you also could use the 3.5mm Millimeter silver lock. It works in the same way. An absolutely brilliant key point of this surgery. Since this is a restraint and nothing which pulls and it's an anatomic structure and not an isometric one, is to find the correct insertion at the femur, which has an radiographic or fluoroscopic insertion point. At the femur, which also has been very nice structured by the, by the guys from, from Naples. And since initially it was really hard to find it by a guidewire, it was then made more easy by using a special template with radiodense lines, which you can control in the Or. And until today, no mpfl in my department is performed without the use of fluoroscope, and it's better to have this as a help, and I can only recommend you to have a printout in the in the patient's file, because this is giving you more security just in case it becomes with a limited range of motion later on. I call it shuttle logistics because you need to pull the gracilis tendon under the vastus medialis. And if you do all at once, you take the risk to have some spaghetti in there. So first use the shuttles to get them out and then back into the femur. Back into the femur. So once you have defined the correct medial layer, you pull first in the shuttle suture. And then under slight tension you bring in the complete graft. And in the second step not doing it at once you pull the graft into the femoral hole by the same way. First get the sutures under slight tension. And I already have the nitinol wire in the femur, because once you pulled in the graft into this small hole in the femur, it can be difficult to redefine this hole and get the screw in. So first, have the suture. The nitinol wire inside. Get the screw over it. And then slightly flexion about 30 degrees. Because this is the position of the knee. When the distance between the femoral and the patellar insertion area of the mpfl is the shortest. You just fix it and don't fix it too hard. Keep the patella in position flush with the lateral condyle, the lateral edge, and fix it. Because it's not. The idea of pulling the patella into the groove is just to have a check rein or a lege that if the patella wants to pop out to grab it. So this is the last thing. And with a screwdriver in place, I check the complete range of motion if there is crepitus or instability, and if not, then I can remove the screw driver. But what do we do in those cases with former surgery? Extended lateral releases and transfers of the tuberosity, which is still unstable, as you can see here. A patient who had already four surgeries and still was unstable to lateral and additional, as you can see to the medial side, the mpfl. Also here can help since you can reclose the lateral retinaculum. Since this also is a stabilizer against lateral dislocation and add the mpfl as just shown before. And it's the same patient a few minutes later with a full free range of motion. You see also the screw drivers in place. It gets removed. It will not stay there for three months. And I got the question before when someone saw it. Side when I put it up. Do you leave it inside? I know what this room's like now. You test it, mean surgery and not later on. Once it's done, it's done. But we also have the other cases. These are, like, has been the mpfl cases. But the cases I've shown you before, like this young girl with this flat or convex trochlea and this ongoing, really drastic popping out patella with an mpfl alone, you will not reach like the complete success. This was one of the young patients who has been treated with an mpfl. Absolutely correct. Performed brilliant placement, good technique. But when she became older, the trochlea became more convex and she still suffered about this dislocation in these patients. If you redo the mpfl, if you don't do it, it stays like this. On the flat plate you have this convex trochlea BioTrochlea. The egg will be unstable. And if you bring an NPFL with really high force, you get it stable as this egg on the table, but for the price of a cartilage damage. So the same patient. We then perform the trochlear plasty to not only give a guidance in the tracking, but also to lower the compression force in between patella and femur. Also here patient who underwent. A light, a big lateral release and a transfer of the tuberosity with a media briefing in a dysplastic trochlea and it still was unstable. Only could extend his knee with very good control of his muscles. And. This is according to the games in Brazil. This ball will not stay on the trochlea as well as will not the patella in this flat cases. Also, if you add an mpfl and therefore we created a new tool together with Arthrex to make those surgeries much more easy. Sorry for that one. As you can see, it's the same patient. The patella was more or less chronically dislocated with a flat trochlea. No guidance. An intensive bump as you can see on the proximal part, because from the diaphysis to the trochlea there was a stair. So the patella always has to hop over it. And we created this pillar. This is a femur. You can add on the typical hand piece of your ACL and PCL guides, which has a distance in between the femur and this little plate. And you can move away the cartilage flap into a movable molding mud and this will leave enough bone so nothing happens. After creating a new groove using a few PushLock, we can easily create a new Trochlea a guidance for the patella, and a few minutes later, the patella has a safe guidance and is even without any any further support safely aligned. So what to do in those patients? Don't go the way over the mpfl. If you see this as before in those patients, I recommend to go directly for a trochlear plasty because if you first start with an mpfl, you only take the risk of creating an arthritis or degeneration and the patient will come back. The mpfl eventually fails and you have no graft left. So we use a lateral approach. We make a natural lengthening of the face using a z-plasty. And here you see there's a tremendous bump. So the patella always has to overcome this bump. Going for an extension to flexion. And there is nothing which is like a trochlear groove. It's convex. It's flat. So after creating a little rim around the patella we use this new great reamer which makes this taking of the cartilage flap really easy. Lift off the cartilage. Create a new Trochlea. We also can use the same reamer for doing it. It's really like smoothening the bone. And then again, using three PushLock, we can bring back the cartilage into the trochlea and refix it so the patella finds a new groove since you've seen it before. I just show you some post-operative controls, no cartilage damage and microscopic staining. We had just like normal bone cartilage layers. A laser stem cell staining showed vivid cells, which has been published, and the same patient just six weeks later, still suffering on the left side, the same six weeks later. On the right side, there is no popping out of the patella anymore. The patient did not lose too much muscles, and she is going to have her left knee repaired in about six weeks. So in general, these are the tools working and the mpfl technique done eight years ago or right now we use the trochlear Plasty is an easy tool and I thank you for your attention.

Trochleoplasty

Anteromedialization (AMZ) procedures have been well documented as an effective treatment option for the correction of patellofemoral malalignment and to unload the lateral patellar facet in deep flexion. The comprehensive T3 AMZ System is designed to achieve precise cutting angles during tibial tuberosity AMZ osteotomy procedures to accurately realign the extensor mechanisms and unload the patellofemoral joint. 
 

Benefits:
<ul>
 <li>Precise, instrumented osteotomy through anatomically referenced cuts</li>
 <li>Fixed angle (45˚, 60˚, and 90˚) cutting guides provide accurate, reproducible control of relative anteriorization and medialization based on chosen angle</li>
 <li>Included soft-tissue retractor protects vital posterior structures 
</li>
</ul>

Eric J. Strauss, MD, (New York, NY) presents a case on a young soccer player who presents with right patellar instability and recent dislocation. Dr. Strauss performs a tibial tubercle osteotomy using the T3 AMZ System combined with a medial patellofemoral ligament reconstruction.

Tibial Tubercle Osteotomy with Anteromedialization (AMZ) and MPFL Reconstruction

Our patient is a 19 year old male collegiate soccer player who presented to the office with recurrent right patellar instability. His initial patellar dislocation occurred two years prior to his presentation, when he was slide tackled during a game. Since then, despite attempts at non-operative management, including physical therapy and bracing, he continued to experience patellar instability. His most recent dislocation occurred three weeks ago, also during a game. On physical examination, he was a thin male noted to be in physiologic valgus alignment. His knee had evidence of a mild effusion. His range of motion was full, but a J sign was evident. He was tender to palpation over his medial patellar fret and along the course of his medial patellofemoral ligament. He had apprehension with applied laterally directed stress with his knee at 20 to 30 degrees of flexion. Plain radiographs demonstrated maintained joint spaces in all three compartments and normal alignment on the AP view, as patella was noted to sit in a lateral position on the lateral view. No significant patella Alta was seen. The merchant view confirmed increased lateral tilt, in addition to a small osseous fragment adjacent to the medial facet. Mri showed evidence of his recent patellar instability event, with bone marrow edema present along his medial patella faucet and the lateral aspect of his lateral femoral condyle on the axial cuts. Trochlear dysplasia was noted to be present in addition to an avulsion of his mpfl from the patella. His tibial tubercle, trochlear groove distance was calculated to be 20.4mm. Based on his history, physical examination, and imaging, the patient was indicated for a tibial tubercle osteotomy to correct his abnormal TTG distance and an mpfl reconstruction. We planned a correction of ten millimeters to bring his TTG distance down to the normal range, using the Arthrex three arms system with the 45 degree cutting guide. The Mpfl reconstruction would be performed using a gracilis allograft fixed to the patella, using two Arthrex SwiveLock anchors, and secured in the femur with a six by 23 millimeter biocomposite tenodesis screw. The surgical approach is performed through a midline incision extending from two fingerbreadths distal to the inferior aspect of the tibial tubercle to one fingerbreadths superior to the superior patella. The incision is made in soft tissue. Dissection is taken down to the level of the extensor mechanism, creating large flaps both medially and laterally, maintaining hemostasis along the way. Once exposed, the lateral medial borders of the patellar tendon are identified, as well as the center point of the tibial tuberosity. A lateral release is then performed using the cautery device, with care taken to avoid injuring the anterior horn of the lateral meniscus. The lateral release is continued inferiorly along the lateral border of the tibial tuberosity. Next, an incision is made along the medial border of the patellar tendon to help facilitate anteromedial ization of the bony fragment following the osteotomy. A straight clamp is then inserted at the junction of the patellar tendon and the tuberosity to mark the mark the superior aspect of the planned osteotomy. The anterior compartment musculature is then carefully elevated from the lateral aspect of the tibia, extending from Gerdy's tubercle to the inferior aspect of the incision. I typically start this with the cautery device and continue with an angled elevator. This allows for insertion of the large retractor posterolaterally to protect the important underlying structures during creation of the osteotomy. With the exposure complete, the tuberosity pin guide is utilized to insert the first guide pin with the t-handle of the guide parallel to the femoral condyles. The guide pin is inserted perpendicular to the shaft of the tibia. Once inserted, I like to take a step back and confirm that the distal aspect of the guide is parallel and the pin perpendicular to the tibial shaft. The 45 degree T3 horizontal guide is then slid into position over the guide pin and held in place by tightening the locking nut and screw. The T3 cutting block can then be then be positioned in a posteromedial to anteromedial orientation, with a distal aspect extending just anterior to the tibial shaft. Two breakaway pins that are inserted at the 50 yard line of each middle slot of the cutting block. The saw blade exit indicator is then inserted into the cutting slot to get a feel for where the saw will penetrate the lateral aspect of the tibia during the osteotomy. Particular attention should be paid most proximally to ensure a safe cut. When satisfied, the threaded colored pin is inserted firmly, fixing the cutting block to bone. We then use the saw blade exit indicator a second time to ensure that we are happy with the plan. The osteotomy is then performed using a sagittal saw. Once complete, the threaded collar pin and the cutting block are removed to create the diagonal proximal cuts. I prefer to use a ten millimeter saw blade rather than an osteotomy, both medially and laterally. With the cuts complete, the osteotomy tibial tuberosity is freed using a half inch straight osteotomy following release of any of any attached soft tissue. The fragment is free to be translated anteriorly and medially, with a hinge of periosteum left distally. The osteotomy tibial tubercle is then medially translated to the desired amount, in this case ten millimeters, with the position checked with a ruler both medially and laterally. With the fragment held in position, a guide pin is inserted, aiming slightly lateral to medial. The position of the tuberosity is remeasured and a second parallel guide pin is inserted. I also employ the use of a third out of plane guide pin to ensure that the tuberosity fragment doesn't travel down the plane of the osteotomy cut during screw insertion. Each guide pin is over drilled and fully threaded. 4.5mm cannulated screws are inserted in lag fashion. It is important to note that each drill hole is sufficiently countersunk to avoid the presence of prominent hardware. Postoperatively. It. The last card pin is removed and Arthrex Quickset calcium phosphate cement is then injected into the defect created during the Anteromedial ization. The Quickset is smoothed with a freer elevator while the Quickset is drying. Any prominence of the transfer tuberosity on the medial side can be smoothed with the sagittal saw. The anterior compartment musculature is then gently re approximated using vicryl suture, tied in figure of eight fashion. The mpfl reconstruction was then started through a small arthrotomy along the medial aspect of the patella. A ranger was used to create a bleeding trough of cancellous bone to aid in graft healing. The initial guide pin is then inserted transversely across the patella, five millimeters from the superior pole. A second parallel pin is inserted ten millimeters distal to the first, both still sitting in the upper 50% of the patella. The anticipated depth of drilling is marked off on the drill, and each guide pin is over drilled. Sutures from the superior tail of the prepared gracilis allograft are passed into the eyelet of the Arthrex SwiveLock suture anchor, inserted into the proximal drill hole and fixed into position. Care is taken to ensure that the tail of the graft makes it into the tunnel. This process is then repeated for the inferior tail of the prepared gracilis allograft. Once fixed, the gracilis allograft is covered in moist gauze and attention is turned to the NFL's femoral insertion. A small incision is made just anterior to the medial epicondyle with soft tissue dissection taken down to bone. Then using a large c-arm on a perfect lateral view. A long beef pin is inserted at this point. Once the appropriate position is identified. The beef pin is advanced in a slightly proximal and anterior direction. Graft isometry is checked prior to drilling of the femoral tunnel. Once satisfied, the guide pin is over drilled with a seven millimeters reamer. Back of the patella. A small clamp is used to open a layer two for graft passage into the medial exposure. A shuttling suture is then used to pass the loop of the graft into position within the medial exposure. This suture is then passed through the femur while a clamp is placed under the limbs of the graft. This ensures that both limbs enter the prepared tunnel, and allows for even tensioning while holding the patella in its reduced position, with the knee at 20 degrees of flexion, a six by 23 millimeter biocomposite tenodesis screw is inserted. Care must be taken to avoid over tensioning, as the graph tends to shorten with the last few turns of the screw. Once complete, translation of the patella is checked and the knee is taken through a range of motion to confirm central tracking. The limbs of the graph can be seen under appropriate tension at the arthrotomy site. A layered closure is then performed. Sterile dressing is applied and the knee placed into a hinged knee brace locked in extension. The key points related to the AMS, I believe, are an adequate release medial to the patellar tendon to allow for translation of the tuberosity fragment. Following the osteotomy. Multiple checks with the saw blade exit indicator to ensure a safe cut. Utilizing the ACL saw blade for the diagonal cuts the third out of plane guide pin to avoid unwanted translation of the fragment during screw fixation. Thorough use of the countersink to avoid hardware prominence, and not forgetting to assess the medial aspect of the transfer tuberosity, which can be bothersome to the patient post-op if proud or sharp with respect to the mpfl reconstruction. I believe the key points are an adequate exposure of the patella to ensure proper tunnel placement. Thinning out the ends of the graft to make sure that they sit within the prepared tunnel. Multiple checks of isometry prior to creating the femoral tunnel. Taking a minute to dissect out layer two on the medial aspect of the knee to allow easy graft passage. And being careful with the last few turns of the interference screw to avoid over tensioning your graft. The Arthrex T3 system is a powerful tool in the management of patellar instability. It allows for precise correction of abnormal TTG distances, is very reproducible and efficient. For the majority of my instability cases, the 45 degree cutting guide is utilized. Thank you very much.

Laith M. Jazrawi, MD, (New York, NY) moves the tibial tubercle medially and distally on a patient with a shallow trochlea and patella alta using the T3 AMZ system.

Tibial Tubercle Osteotomy With Distalization Using the T3 AMZ System

The patient is a 22 year old female with a history of patella Alta and left knee pain. The pain has been present for many years but has been increasing over the last several months. She has failed all conservative therapy. X-rays confirmed patella Alta and measured by the Khitan Deschamps ratio at 1.5. Pre-op MRI confirms the lateral cartilage based lesion and the lateral patella tilt. Skin markings are placed in preparation for the tibial tubercle osteotomy. Diagnostic arthroscopy is performed. Medial compartment inspection is free of any meniscus or cartilage. Pathology. Acl is intact. Lateral compartment reveals loose cartilage bodies from the lateral facet of the patella. The patellofemoral compartment is visualized showing a lateral facet cartilage lesion. This is to breed with a shaver down to a smooth margin, as is seen here. A lateral release is performed, as is seen here, starting at the level of the VMO and extending distally to the medial portal. The incision for the tibial tubercle osteotomy is performed. This starts roughly at the level of the tibial tubercle, extending distally approximately 7 to 9cm. The patella tendon is identified to protect it and at the level of gerdy's tubercle. An L-shaped incision is performed to allow elevation of the anterior musculature. This is done with a bovie. And then this is followed by blunt elevation with an elevator to allow for protection of the neurovascular structures with a retractor. The medial aspect of the tuberosity is freed of soft tissue as well. The tuberosity pin guide. And guide pin are inserted. The 45 degree arms guide is then placed on the tuberosity pin. With the angle being proximal and posterior and distal and anterior. The breakaway pins are inserted to stabilize the guide. The blade indicator is placed to make certain that the posterior cortex of the tibia is not violated. This is placed at multiple levels along the guide to make certain that the angle is correct. The final colored pin is inserted to stabilize the cutting guide and the breakaway pins are removed. The tuberosity pin is removed as well. Visualization from multiple angles confirms that the posterior tibial cortex will not be violated. And this is double checked prior to performing the osteotomy with a sagittal saw. The posterior soft tissue retractor is inserted and utilized to protect the neurovascular structures. After the osteotomy is complete, we utilize a smaller saw to complete the proximal aspect of the osteotomy, as is seen here. Making certain not to angle the saw towards the joint. Osteotomies are utilized to free up the tibial tubercle. And the posterior hinge is removed as this is a distalization procedure. Soft tissue is removed distally and one centimeter of the of the distal aspect of the tibial tubercle osteotomy is removed. With the knee in 30 to 45 degrees of flexion. The osteotomy is then reduced distally and medially by one centimeter. This allows correction of the patella. Alta and conformation of the medialization is performed. Three guidewires are inserted, stabilizing the fragment, and then the sizes are measured off the wires. The profile drill is initially utilized in preparation for insertion of the headless screws. These are then sized with a depth gauge and the 5.0 headless screw is inserted. The profile drill is then inserted distally. And the headless screw inserted. And the final screw inserted proximally, stabilizing the osteotomy. The knee is taken through a range of motion, confirming that the osteotomy is stable and final X-rays confirm appropriate positioning. Allosync putty is then inserted at the osteotomy site, and after the wound is thoroughly irrigated and the tourniquet released. Three zero vicryl is utilized to close the subcutaneous tissue. For a monocryl, and dermabond is utilized to complete the subcuticular closure. Post-operative management included for the first six weeks. Non-weight bearing with crutches. With the knee locked in full extension. She had range of motion as tolerated with CPM for two hours, three times daily from 0 to 30 degrees of flexion. Out of the brace in terms of PT at this time, she did heel slides, quad sets, ankle pumps and seated leg raises. By week 6 to 8, she progressed to weight bearing as tolerated with crutches, and it began to advance to her normalized gait pattern without crutches. The brace was unlocked for ambulation and removed for sleeping, and CPM was discontinued as she reached 90 degrees of flexion by this point. By weeks eight through three months, she started full weight bearing. She discontinued her crutches and she discontinued her brace at this time. Post-operative x rays confirm normalization of the Deschamps index from 1.5 to 1.13.

Patellofemoral Realignment and Reconstruction

MPFL Reconstruction

Trochleoplasty

T3 AMZ System for Tibial Tuberosity