(0:00) Myself and Kristian Kley, my good friend, are here today to really help everyone with a problem (0:07) that seems to be repeatedly asked at all the courses. How do you manage the MCL in a high (0:14) tibial osteotomy procedure? How do you preserve the PES? And how do you physically release the (0:19) superficial MCL? And we're going to take you through that with a cadaveric demo. The second (0:24) thing that we'd like to share with you today is how do we protect the neurovascular bundle (0:30) at the back of the tibia in a more effective way than we've currently been doing.
And we're going (0:36) to do that with a fantastic idea that Kristian has had to come from a posterior approach behind (0:44) the MCL with a new retractor that he's designed and we're going to show you how that works.
(0:50) Okay, so we're looking at a model of a knee. Obviously we have the extensor mechanism we have the (0:55) MCL. When we're doing our osteotomy surgery we have to do something to the MCL which we're (1:03) about to demonstrate to you in this video, but also very importantly we have to protect the (1:07) neurovascular bundle at the back. Now if we show you where the neurovascular bundle is, it sits (1:12) just here.
With our current approaches we have to peel back the medial collateral ligament and as (1:18) we peel back the medial collateral ligament we introduce our retractor but the angle is always (1:24) posterior, straight towards the neurovascular bundle. We force it back and we try and get it (1:30) flat but we're always fighting against the medial collateral ligament. So if we show you and we're (1:37) going to show this in a little bit more detail, the guide that Kristian has developed, we can (1:41) introduce this into the back of the knee and we could go like so and cut the tibia but we're fighting (1:46) the MCL.
So Kristian has had this very very interesting concept of actually making a separate (1:53) incision at the back of the tibia and introducing our retractor behind the MCL in a posterior to (2:02) anterior position, uphill, working our way along the back of the tibia such that we're behind the (2:08) MCL for the entire procedure. Once that is in position he has also had another further very (2:15) good idea to lock this guide into position with a wire. We're going to show you that in a video too.
(2:21) Okay, looking at the retractor now we have loaded a 19 L wire in this. (2:26) Can you show us the back of that retractor so we can see where it's going? (2:29) It's going in the handle all the way through this tube coming up here with quite a sharp curve of (2:37) 75 degrees and then from the back which is located outside of the patient you can advance (2:46) the K-wire to be positioned in the back in the very back of the tibia. So that's the typical (2:52) position where the retractor is located. So what we then do if we under fluoroscopic control have (3:00) proven this is the right position to have the retractor we just advance our K-wire by oscillation (3:09) and guide it into the tibia.
Okay, so that's the position of the retractor and once (3:15) it's in place you just advance the K-wire and shoot it in so that it locks in the back (3:26) of the tibia and once it's locked in the back of the tibia you cannot really move it any further (3:32) so there is no chance of losing your position. And where would the neurovascular bundle be at (3:36) this point? Here, directly here in the back protected by the popliteus that sits even over (3:43) this retractor.
Okay, so what we're talking about here is a whole new approach to releasing the MCL.
(3:50) Try to move. We're going behind the MCL we're going to show you a separate (3:54) incision we're going to lock the retractor in place we're going to lock it into the bone and (3:59) we're going to be superficial anterior to the neurovascular bundle as well as the popliteus (4:07) and we're going to demonstrate that to you now.
So just to walk you through the anatomy we've (4:11) identified the back of the tibia we've got the front of the tibia we've got the medial (4:15) femoral condyle and the epicondyle and we've got the superficial MCL inserting down onto the tibia (4:21) we also have the PES coming in.
So where do we make our incision first? Let's show you where we (4:31) would make a mini incision and let's show you a more standard incision. So first our preferred (4:37) incision is slightly oblique just below the joint line maybe 4 centimetres gives you more than (4:44) enough particularly with the small plates like the Activmotion plate from Newclip and you can (4:49) see that here and Kristian is about to incise the tissue. So first we go through the skin and we (4:55) go through down to the fat and we see the fat very clearly and Kristian is now just moving the fat (5:02) away and we can see underneath we've got the subcutaneous fascia.
What we do next now is we're (5:10) going to make a more maximally invasive approach we're going to show you a more standard incision. (5:14) So for beginners we would recommend that you make this incision slightly longer because of course (5:20) you're going to have better visualisation. Now what we're going to do is we're going to excise (5:25) a skin flap and we're going to show you the anatomy and walk you through the next steps (5:30) in releasing the MCL.
Okay so what we can see Kristian has done here is we have the extensor (5:36) mechanism we have dissected out the patella tendon and we're going to show you how we would (5:43) normally come underneath here and we can see there's the tibial tubercle and there's the (5:50) extensor mechanism. For the biplanar cut we would make it in this orientation here. (5:55) Then we're going to show you the PES and here we can see Kristian is going inside and he's (6:02) just literally opening up you can hear the crack crack crack he's opening up and he's releasing (6:08) the PES as it comes down onto the tibia.
So all he did was he let's rotate it around so the camera (6:14) can see inside all he did was go inside and he opened up and that pushed the hamstrings away (6:23) and you normally get a kind of cracking noise as you do that. Now we can identify the superficial (6:31) MCL we can see it clearly and what we're going to do is having identified the superficial MCL (6:40) we're going to show you first the problem of trying to do as a traditional MCL release and (6:47) retractor position. So traditionally we would come down from the front don't release it just yet (6:52) because we need the tension for your technique.
So we would release the MCL like this and then (6:59) we're fighting the whole time fighting fighting fighting the orientation of the retractor. So as (7:07) we're putting our retractor in it's heading posterior straight towards the vessels from (7:12) front to back we don't want this. So the concept that we have had or Kristian has had is to make (7:19) an incision on the back behind the MCL.
This is very easy to do and we find the MCL and we just (7:26) release it. Now for the sake of this demonstration we're going to release the PES so that you can (7:33) see what we're doing more clearly. So we're just going to come in now and release this PES.
(7:37) Take the PES off. (7:43) Good now we see the back of the tibia and the idea is to make a small incision on the (7:51) back of the tibia as you can see Kristian doing here just like this and now when we place our (7:58) periosteal elevator or retractor in we're heading from the back and listen (8:05) you can hear Kristian scratching the back of the tibia (8:09) and he's coming from posterior to anterior completely safely. Now you leave this retractor in (8:16) can you hold it? Do you want to use the small one? That's perfect now we leave this (8:22) retractor in as a guide to hold back the popliteus. Introduce this one now you can take it out please (8:31) advance this one further all the way to this position.
So you can see the MCL is still intact (8:39) with behind the MCL and Kristian is coming from at posterior to anterior and we're going to lock (8:45) this into position with a wire that goes down the middle of this novel guide that we've designed. (8:57) Good so now the guide is locked in place it's locked into the bone so when our saw comes down (9:04) the saw will be following the line of the retractor in a completely safe fashion.
(9:08) We're going from posterior to anterior and this is the way that high tibial (9:14) osteotomy surgery is going to be carried out in the future and now we release the immediate collateral.
(9:19) So now Kristian is going to show us the next step would be to release the MCL this is very similar (9:25) to how we do it in a total knee replacement. So you can see all he did was he took any kind of (9:31) periosteal elevator and he just elevated that tissue away and he's now placed his second retractor (9:38) which is a more traditional retractor position and we are good to go and we're good to cut the bone (9:44) in a completely safe fashion.
He's a very clever man. Very good okay that's it nice. (9:52) We'd like to show that actually the retractor is completely locked in the bone so Kristian is (9:57) moving the entire bone with a retractor that is locked.
Now what we will be designing very shortly (10:03) we've got the designs and we will show you is a way of tracking this retractor with the saw (10:08) so that the two are locked together and that is an innovation that we'll be sharing with you very shortly.
