Orthobiologics

Procedure

Product

The segmental meniscus transplant technique addresses failed repair of the meniscus while avoiding total replacement. Patients who have irreparable defects can benefit from a partial replacement, completed using the segmental meniscus transplant technique, which provides the same tibiofemoral joint compartment biomechanics as an intact meniscus.1-3 This technique helps preserve the native biomechanical loading principles of the knee while keeping intact native hoop fibers.
References
1. Strauss E, Caborn DNM, Nyland J, Horng S, Chagnon M, Wilke D. Tissue healing following segmental meniscal allograft transplantation: a pilot study. Knee Surg Sports Traumatol Arthrosc. 2019;27(6):1931-1938. doi:10.1007/s00167-019-05355-z
2. Seiter MN, Haber DB, Ruzbarsky JJ, Arner JW, Peebles AM, Provencher MT. Segmental meniscus allograft transplantation. Arthrosc Tech. 2021;10(3):e697-e703. doi:10.1016/j.eats.2020.10.059
3. Nyland J, Campbell K, Kalloub A, Strauss EJ, Kuban K, Caborn DNM. Medial meniscus grafting restores normal tibiofemoral contact pressures. Arch Orthop Trauma Surg. 2018;138(3):361-367. doi:10.1007/s00402-017-2849-x

Knee

Not Hidden

English  - en

application/pdf

Human

Segmental Meniscus Allograft Transplantation

Patrick A. Smith, MD (Columbia, MO), performs a segmental meniscal allograft transplantation procedure. The entire technique and several pearls are included, including defect preparation and measurement as well as graft preparation and fixation. Stable fixation is achieved using the ZoneNavigator™ device to complete inside-out suture delivery and the FiberStitch™ implant for side-to-side fixation.

video

Segmental Meniscus Transplantation Surgical Technique

So this is a left knee. And we're going to demonstrate a segmental meniscal transplant today. Left knee. This patient had a partial medial meniscectomy. You can see here a pretty classic tear that's been trimmed to the posterior horn. Here's our route. And this was the transition of removing the tear. So the first order of business is we want to prepare for the allograft segmental transplant. So I like to remove much of the native remaining meniscus back to about a millimeter or so for the meniscal sites to help regrow into the allograft segmental transplant. So first thing we do is we've got to prepare this rim. So I'm going to come in in the area of the tear, come back toward the capsular attachment and remove the remaining meniscus. Here, a millimeter or two to the rim is what I like to do. And then we'll prepare the rim with a rasp. To further enhance the ability for this incorporation of the allograft. So I try to leave a 90 degree angle here to the back, where we'll suture the segmental to the native area of the posterior horn, there and here, up to the anterior aspect of the area of the tear. So there's our preparation. You can see we've got back about a millimeter or two of the native rim, and that's where our segmental meniscus is going to fit in. Now I take my meniscal rasp, and I want to stimulate bleeding from the native capsular attachment here. This is where the blood flow is to the meniscus coming from the periphery. So I'll go here a little bit underneath the capsule. To help enhance the healing here. And then we've got to measure our defect. So these are two millimeter marks so we can measure. There's ten is the bold mark there 2022 looks like 24 there in terms of our anterior posterior dimension. So we're going to use our ZoneNavigator. And we're going to pass our four sutures in the native remaining meniscal Rim, and that is how we will pull the segmental meniscus into the joint and attach it and actually suture it to the capsule. So we have the ZoneNavigator and we're going to pass first the posterior superior suture. So here's our needle loaded. Passing through the native rim of meniscus. And retrieve that needle percutaneously on the posterior medial side. So there's good position of that needle. And now we're going to pass a suture a shuttle suture. So we have our TigerLink. We'll pass the free end. And the loop part of the link will allow us to pull the meniscal sutures in for the actual segmental transplant. Okay. Perfect. So that's our first suture. Now we're going to place our second suture. Posterior. Inferior. [00:03:10] Put it in. Now we'll do the same thing. We'll take another tiger and pass it through the loop part of our wire. So for distinction. So we know which one is superior. This is just a straight FiberWire suture. Fiberwire. And this is a SutureTape. So it has a double black on it. So this will orient us so we know which one is posterior superior and which one is posterior inferior. When we pass the corresponding sutures placed in the segmental meniscus posteriorly. So now we're going to take our ZoneNavigator. I've moved the scope to the medial portal. And I'm going to come in laterally now and make our pass for the anterior superior. Anterior inferior. So here's the anterior superior. Again we're passing our needle which has the loop on the end. And we use that loop to pass through our sutures. And here we're going to use a blue FiberWire and a blue SutureTape to distinguish. So here's our blue FiberWire which will be our anterior superior shuttle suture for the graft. And now we'll pass our anterior inferior. Right. So you get a feel here of our management of these four sutures. And these four sutures will pull the graft in oriented the two posterior ones super inferior, the two anterior ones the anterior inferior. So the last thing I'm gonna do is I'm just going to check the depth from the capsule rim to the free edge. And this is a probe. Those are marks are five millimeters. So it looks like it's about ten for the depth of our segmental graft. So our next step here for suture management is we place the 12 millimeter passport in the medial portal. We have our four quadrant divider. So now we can separate our four sutures which will make a big difference in terms of later passage. So I'm going to come through here first. And I'm going to grab the posterior superior TigerWire suture and pull it out one slot. So now I'll come in just below that and grab the posterior inferior. So this is really helpful to keep these separate. So when we pass our graft we'll have our sutures all in the right spot. Now I'll come in and grab the anterior-superior through the top left divider. So now we'll get the anterior inferior, which is right there through our last segment down here. So now you can see the divider. We've separated the posterior superior posterior inferior anterior-superior anterior for. So we're in those quadrants now which will make the passage of our sutures in the meniscal segmental transplant much easier when we pull it into the joint. And then we'll tie those sutures that we pass directly on the capsule for our fixation. So before we go and create the exact match for the segmental meniscal, the last measurement I want to do is just how far I am from the posterior defect to the root. So when I go to the to the specimen, I can match that up. So you can see here to the root attachment I'm about six millimeters Maybe seven. So that will allow me when I go back and cut the specimen, I'll try to leave seven millimeters from the root of the specimen. And then of course, cut 25 to the front. Just a reference point that I think is helpful. Now we'll go back to our back table and prepare our segmental meniscal specimen to fit. This is our meniscal allograft medial meniscus. So now we're going to cut the suitable segmental allograft. And based on our measurements intraoperatively, we're going to measure seven millimeters from the root and make a mark right at the ball there. And then we're going to make our first cut. And we remembered our orientation which was slightly oblique. So it's not so much in that plane. But we remembered what we did. We were slightly oblique. We're going to come back to the capsule in that plane. And we want to take a little bit of this capsule attachment for blood supply. Apply. If we're a little bit big, we could trim the inner aspect if we need. But we think for healing we need this capsular attachment. So intraoperatively we measure 25 with our anterior posterior. But I think for sizing purposes, cutting one millimeter or less is best. So we make sure that the segmental meniscus fits ideally. And then we can tension it with additional suturing if we need to. But I do not want it to be too big anterior to posterior, because then you'll have to cut it again. So our experience has been to cut it one millimeter less. So here's our mark. We're going to go to 24 kind of from the mid portion of the viscus where we measured from make our posterior mark there. So now we're going to make our second cut. And this one is a little bit oblique in the opposite angle. So we're not going to cut like this. We're going to cut more like that. So remember our angle visually. So we're going to make our cut in this plane right here. So there were put our measuring device. We're right at 24, which is what we wanted one less than what we measured intraoperatively. And what I was saying is we might be a touch long here. We're measuring about 12 to the rim. But if we needed to trim a little this on the free edge, we could. This is the working part of the meniscus. Your circumferential hoop fibers. That's what you're trying to preserve here. So now we have to pass our sutures in the peripheral aspect of the meniscus that will tie to the capsule using our shuttle sutures that we placed on the joint side. So if you put the meniscus on end here's the posterior aspect. So first I'm going to pass with this small needle with a loop on it. I'm going to go through the posterior inferior segment of the meniscus here through the capsule getting a good bite. And we'll pass now the black and white which corresponds to the posterior inferior suture we passed on the joint side. We're going to create a cinch here. So this will give us good purchase in the meniscus. So that's our first pass. So now we're going to create our cinch. Give us good purchase in this peripheral aspect of the meniscus. [00:10:23] Okay. That's not going to work. Okay. So that's our posterior inferior. So we're passing posterior superior. So we have our shuttle loop. This is for our other cinch black and white. And we'll create this cinch. [00:10:54] Oh that's hard. So what you can see here is when we tie to this the capsule, we're going to tie these two on the outside of the native capsule to pull the meniscus and hold it in place. And you get great purchase because of the thick circumferential hoop fibers peripherally with the meniscus. So this really gives you a really good purchase. So here's our prepared segmental allograft getting ready to transplant into the patient. So as we've been talking about for suture management purposes, we have passes through the peripheral aspect of the meniscus posterior inferior double black hair and posterior superior single black. And that will correspond to the same suture we placed earlier for passage. And then the anterior aspect anterior inferior is striped and the anterior superior is plain blue. So blue in the front, black in the back through the peripheral aspect of the meniscus. And those are cinch sutures. So we have a good purchase the meniscus. And then we're going to tie the anterior superior to the anterior inferior posterosuperior posterior inferior directly on the capsule to get our fixation. So again here's our graft oriented. Remember the two black cinches in the posterior of the meniscus. The two blues anterior. We've got a great team helping me here. So we're going to now pass the corresponding double black with the previously passed suture through the posterior inferior aspect of the meniscus. And now let's pass. We'll pull that through. And we'll pass the posterior. Superior. Now again, we're color coordinated to keep things straightforward. Then we'll use those two with the KingFisher to deliver our graft into position. So now we're going to come through our meta portal. We had taken of course the passport cannula out. So use the KingFisher to guide my graft in. We made that portal just a little bit bigger. So now you can see we delivered the posterior part in. We'll maintain traction on that. And now we very simply just pass our blues for the anterior and we secure our meniscus. We'll just double check to make sure our passport helped us. We'll make sure we're not crossed it all. There's our bottom, so we're clear there. So there's no soft tissue bridges. So we're clear. And again the passport with the dividers allowed us to do that. So now the double blue is the posterior inferior. You can see there on the screen coming through. Okay. Perfect. So you can see what we're doing now we've passed these and we'll tie those directly to the capsule. It'll give us great fixation with the peripheral aspect of the allograft transplant to the native capsule, which we prepared earlier, including the rasp, to help get some good healing. And then we'll finish the repairs needed with some FiberStitch all-inside sutures. So you can see it looks like we have a nice fit. And again, if we needed to trim a little this free edge, we could. I'm more interested in having that good, secure capsular tissue for security of the meniscus. So if we had to trim a little bit of this in the back, we could. But we'll see. We might make that up with the FiberStitch in the back. We'll put a FiberStitch here and here and one in the front. So I'm tying these sutures down to the capsule, and that's reducing the meniscus even more. So through a small medial incision, we're tying directly to the capsule. That's what I'm doing here for our posterior superior. Posterior inferior. Now I'm going to tie my anterior-superior. Anterior inferior. So you can see we've got this peripherally sewn. And here we might trim a little of this, but that's okay. So now we're going to put an on side FiberStitch in. And just to help reduce that just a bit better in the front. So we put our half pipe in. For our FiberStitch we have different curves. So we're just delivering our FiberStitch. Then come to the front of the native. Take our probe. Bring our mattress down and complete it. So this is the cutting device. So we've loaded the suture. We just bring it down to the knot. Push and cut. So you can see we've got an excellent reduction now anteriorly. Now we'll put one posteriorly. So here's our completed segmental meniscal allograft transplant. And I just trimmed a little bit of that back edge. Remember this. This graph was not matched to this patient. So but you think I think we had a very good fit. You can see here's my spanning suture to the posterior horn. Anterior horn I've got two the capsular sutures tied. And we put that additional vertical mattress. So it's totally stable. Can't displace it at all. We replaced the meniscus. It's pretty normal. So really happy with how that came out. Put the knee through a range of motion. Flexion. All the sutures hold. Fine. You can see the meniscus. Femur rolls back. Meniscus goes with it right there. Meniscus going back with the femur. Normal rollback. So really happy with that transplant.

J. Lee Pace, MD (Plano, TX), discusses the scientific support for segmental meniscus replacement to treat irreparable meniscal deficiencies. Dr. Pace also reviews biomechanics and surgical considerations when treating these deficiencies.

Segmental Meniscus Transplantation for Irreparable Meniscal Deficiencies

Hello. Lee pace here from Farmington, Connecticut. Today I'd like to talk about something new and exciting. And this is the concept of segmental meniscus transplantation. As we are all aware, there is a significant burden of meniscus injury in this country and around the world, with societal costs ranging from 500 million to 5 billion annually. This is due to the historical treatment of these meniscus tears to include mainly partial meniscectomy, although it does provide good short term results. The rate of osteoarthritis is proportional to the amount of meniscus removed, so there has been a large shift in thinking and practice to save the meniscus. Over the past decade or so, there has been a lot of focus and energy on innovating new techniques and new products for meniscus repair, as well as research to study its outcomes and feasibility. Here's an example of a complex lateral meniscus tear, which in the past would have been meniscectomy. But now, with products such as the knee Scorpion, we can now perform a very reliable repair. Here's another example of a more complex posterior horn medial meniscus tear, in which there are two separate tears present. In the past, this would have been at least partially meniscectomy. Nowadays we can do a robust and reliable repair. This is an inside out technique using the ZoneNavigator and this also went on to complete healing. In fact, these meniscus tears are in the same patient and she's doing great. However, we do encounter the problem of meniscus deficiency. We have some meniscus tears that are chronic or just too complex to fix, and we are left with a situation where someone has a subtotal loss of meniscus tissue. For many years now, we have been able to successfully perform and improve our techniques with meniscus transplantation. To help with this very difficult problem of meniscus deficiency, we have now identified sort of a new problem when it comes to meniscus preservation segmental deficiency. There are some meniscus injuries that behave as a complete meniscectomy, where you still have a lot of native meniscus tissue left, but you have a defect present that makes the meniscus behave as if it was a complete meniscectomy. A classic example is here with a segmental radial defect. You can perform a complete meniscus transplantation here, but it requires a removal of a lot of native meniscal tissue. And in this example here you can see that I had to remove the entirety of the posterior and anterior horns of this lateral meniscus so that I could perform a complete meniscus allograft transplantation. So the question is, is can we perform a focal segmental meniscus transplantation? So let's now dive into the science that's been looked at so far with this question. First off let's look at what's been done with biomechanics. This is a study out of Kentucky looking at an animal model. This is a 4K model in which 12 knees were evaluated by creating a segmental radial defect. In the medial meniscus. There were three states intact the segmental defect and then the grafted defect. An axial force was applied in differing degrees of knee flexion, and they collected data on mean and peak pressure, peak pressure location, and peak pressure area. The results are fortunately not surprising. What they showed was that in the segmental defect model, there was increased pressure, a mean pressure and peak pressure, as well as a decreased peak pressure area in the segmental defect, and that by performing the segmental replacement that it restored all of these parameters back to normal. So from a biomechanical status, this can be performed. Now the next step is biology. Will this heal? Can you get an allograft meniscus to heal on the borders successfully? In this animal study from the same group looking at segmental meniscal transplantation in a sheep model, they were able to evaluate the histology at the borders of the native and transplanted meniscus at 90 days. Now, interestingly, three sheep were euthanized early, and so they were able to be evaluated at 40 days, which created sort of an internal control for the sheep that were evaluated at 90 days. What they found was very interesting that even in the sheep that were euthanized early, there was evidence of partial healing, particularly at the areas of the side to side repair. And then in the sheep evaluate at 90 days. This healing trend continued, and we should take these results in context, because the repair construct that was performed was rather basic and did not take advantage of all of the tools that are currently available. And further, it was performed in a rather hostile animal model in which there was no ability to have protected weight bearing after the meniscus transplantation. Now, to take the next step, there is now a published technique for performing an open segmental meniscus transplantation in a human, and this technique comes from Matt Provenza's group with some pictures shown here. You can see the segmental grafted defect in the medial meniscus here with a robust fixation construct. So now let's talk a little bit about indications. Obviously this is early. And so these indications will be evolving. However we think that prime indications for this include segmental defects between 2 to 4cm due to either failed prior repairs or irreparable segmental defects. Classic examples of this would be radial tears or irreparable posterior horn tears of the medial meniscus. It would require intact meniscal roots as well as appropriate cartilage, stable ligaments, and neutral alignment. The next step in the evolution of this is reliable arthroscopic techniques. Using some of the tools that are available to us to include the ZoneNavigator, the knee Scorpion, and the FiberStitch. And in fact, these are pictures from my work in the lab successfully performing an all arthroscopic segmental meniscus transplantation of the posterior horn of the medial meniscus. There is still a lot of work to do. We do need further animal and biomechanical data, and we want to follow that up with clinical studies looking at further indications, patient reported outcomes, rehab protocols and expected functional levels after surgery. In conclusion, segmental meniscus transplantation represents the next step in meniscus preservation and restoration. We have lots of work to do. However, I think we're all looking forward to some very exciting results.

Matthew T. Provencher, MD (Vail, CO), presents a case of focal meniscus deficiency treated with a segmental meniscus allograft transplantation. Dr. Provencher also shares several technical pearls and concomitant procedure considerations for this case, in addition to his rehabilitation protocol.

Segmental Meniscus Allograft Transplantation for a Focal Meniscal Deficiency

Hi, I'm Matthew Provencher from Vail, Colorado, and I'm going to talk to you today about a segmental meniscus transplant, a case study. This is a 37 year old, very active female who's had several knee surgeries prior, including an ACL reconstruction with a failed prior meniscus repair, and then had two subsequent partial meniscectomy on the medial side. She presented with medial persistent pain and an inability to return to her activities, including just activities of daily living. She also had a problem with her knee due to some malalignment, as well as some early grade chondromalacia and focal grade four defects of the medial femoral condyle, as well as a focal meniscus deficiency. Her preoperative weight bearing imaging, as well as her hip to ankle radiographs, demonstrate overall pretty well preserved joint space, no significant osteophytes, and overall a varus right knee weight bearing axis right around 25%. Her preoperative MRI on the axial demonstrates the focal segmental medial meniscus deficiency. It's approximately 15mm from anterior to posterior, but she does have intact anterior and posterior horns as well as intact roots of the medial meniscus. Her coronal view also highlights a focal cartilage defect that's focal grade four, but also highlights very nicely her focal medial meniscus deficiency right in the center portion of the medial meniscus. So we have a young female with a focal segmental medial meniscus deficiency, approximately 1.5cm from anterior to posterior, but intact anterior and posterior horns of the meniscus, as well as intact roots. She has a focal medial femoral condyle defect, grade four, and also varus malalignment at about 25%. The treatment plan for her was a focal segmental medial meniscus transplant. To address her focal deficiency of about that 15mm or so, as well as a additional medial opening wedge high tibial osteotomy to correct her varus alignment back to neutral, as well as a fresh osteochondral allograft implantation of the focal defect on the medial femoral condyle. Her diagnostic arthroscopy reveals a focal medial meniscus deficiency. As noted here, when measured and templated intraoperatively, this is about 18 to 20mm. After you get back to a very nice stable anterior and posterior rim. Of note, her anterior and posterior limbs of the meniscus were intact, started first with the alignment and condyle damage addressing with a focal osteochondral transplantation of two plugs, followed by a high osteotomy using a wedged osteotomy plate. The segmental medial meniscus transplant starts after you trim the meniscus back to stable normal borders. This was measured at 20mm after the medial meniscus was adequately debrided to a good stable rim, which is important to accommodate the side to side transplantation sutures. After this is done, we use a variety of spinal needles or other passing devices to come under, as well as on top of the meniscus, and pass some initial sutures to shuttle the meniscus in from both front and back. The graph preparation is shown here. We obtain a medial meniscus transplant. It is measured out and templated and matched to her defect after preparation. This is right around 18 to 20mm, depending on where it's measured in the meniscus. We then harvest the segmental portion of the meniscus that we're going to transplant, leaving the remaining meniscus on the back table. Once this is done, we then do progressive stitch shuttling through the medial meniscus such that the sutures will match up to the sutures that were passed in the knee. This is the final construct prior to implantation, where we have multiple vertical mattresses that match up with our prior past sutures. Because we had already done the osteochondral Allograft as well as the osteotomy. We have an open arthrotomy which facilitates approach as well as graft positioning and placement. Of course this can be done all arthroscopically, but since we were already open, it was chosen to be done this way just for ease of passage. The graft is passed in with something such as a KingFisher and put into position as the assistant. Gently tensions down the sutures through the capsule from an inside out type of repair. Two FiberTak anchors, 2.6mm size, are utilized to help fix the meniscus at both the front and posterior portions. These are placed right on the most medial margin of the tibia, and then cinch down. After transitioning one of the sutures that had already been passed in the meniscus, and then put in through one of the anchor knotless sutures for fixation. Thus, the final construct is five vertical mattresses pass through the capsule and tied inside out. The anterior and posterior portions are also incorporated into native tissue with number two non-absorbable suture. And then it's further anchored to the tibia with a 2.6mm knotless FiberTak suture anchor. This is the final construct as demonstrated here. And you can see the side to side radial type of suture, as well as the sutures that are placed through the capsule. And then deep at the tibia margin are the two FiberTak anchors. Her post operative imaging is demonstrated here showing the osteotomy construct bone graft. And you can also see some small hint of bone tunnel for the tack anchor post-operatively. This patient will be touched down weight bearing for a total of five weeks, with a hinged range of motion brace starting at 0 to 90 degrees right away, with both passive as well as active assist motion, and working on quad sets as well as hamstring activation. The hinge knee brace will be discontinued after about five weeks, when range of motion as well as weight bearing will be progressed and she'll be allowed to return to full activity between 5 to 6 months.

Segmental Meniscus Transplant

Child (D)

The dovetail technique simplifies graft preparation with a time-saving series of cuts preparing the bone component of the graft to sit securely in the recipient semi-trapezoidal slot created in the tibia. A matching semi-trapezoidal shaped recipient slot created in the tibia with a series of step drills, rasps and dilators matches the bone block preparation. Subsequent peripheral graft fixation to the capsular rim with 2-0 FiberWire® achieves the goal of creating a solid meniscal allograft construct. Preferably performed for lateral meniscal incompetence, the dovetail technique anatomically recreates the normal lateral meniscal relationships within the knee.

Meniscal Allograft Transplantation Featuring Dovetail Meniscal Allograft

Dovetail/Slot Meniscal Transplant Technique

The Double Bone Plug technique for meniscal tear/deficiency utilizes bone plugs that can either be prepared freehand or by using a coring reamer. The freehand technique is performed using rongeurs and a high speed burr. For detailed information about this technique and/or Arthrex products utilized in this technique, visit the educational resources tab or products tab below. The double bone plug technique for meniscal allograft reconstruction provides a method for implanting the meniscal allograft medially with rigid fixation at both horn attachments. It has been demonstrated that bony fixation and bony healing at the attachment site allows for the maintenance of functional hoop stress by the meniscal allograft.

Double Bone Plug Meniscus Reconstruction

Double Bone Plug Meniscal Transplant

ZoneNavigator System Cannula - Anterior

ZoneNavigator-System, Kanüle für Anterior, VE5

ZoneNavigator System Cannula - Anterior, VE5

CÂNULA DO SISTEMA ZONE NAVIGATOR - ANTERIOR

CÂNULA DO SISTEMA ZONE NAVIGATOR - ANTER

ZoneNavigator, Left Middle / Posterior Cannula

ZoneNavigator-System, Kanüle, links, für Mitte/Posterior, VE5

ZoneNavigator System Cannula - Left Mid/Posterior, VE5

Cánula angulación izquierda ZoneNavigator

CANULA DO SISTEMA ZONE NAVIGATOR - MEDIO ESQUERDO / POSTERIOR VE5

ZoneNavigator, Right Middle / Posterior Cannula

ZoneNavigator-System, Kanüle, rechts, für Mitte/Posterior, VE5

ZoneNavigator System Cannula - Right Mid/Posterior, VE5

Cánula angulación derecha ZoneNavigator

CANULA DO SISTEMA ZONE NAVIGATOR - MEIO / POSTERIOR DIREITO

Soft-tissue meniscal allograft transplantation techniques continue to evolve with the advancement of fixation devices. Using common meniscal repair devices allows for greater flexibility while ensuring anatomic graft placement. Soft–tissue-only meniscal allograft surgical techniques and clinical outcomes are well documented and have good clinical efficacy.1-4
References
1. Kim SH, Lipinski L, Pujol N. Meniscal allograft transplantation with soft-tissue fixation including the anterior intermeniscal ligament. Arthrosc Tech. 2019;9(1):e137-e142. doi:10.1016/j.eats.2019.09.015
2. Spalding T, Parkinson B, Smith NA, Verdonk P. Arthroscopic meniscal allograft transplantation with soft-tissue fixation through bone tunnels. Arthrosc Tech. 2015;4(5):e559-e563. doi:10.1016/j.eats.2015.06.001
3. Elattar M, Dhollander A, Verdonk R, Almqvist KF, Verdonk P. Twenty-six years of meniscal allograft transplantation: is it still experimental? A meta-analysis of 44 trials. Knee Surg Sports Traumatol Arthrosc. 2011;19(2):147-157. doi:10.1007/s00167-010-1351-6
4. Myers P, Tudor F. Meniscal allograft transplantation: how should we be doing it? A systematic review. Arthroscopy. 2015;31(5):911-925. doi:10.1016/j.arthro.2014.11.020

James L. Carey, MD, MPH (Philadelphia, PA), demonstrates a soft−tissue-only meniscal allograft transplantation and provides a full overview of the technique, from preparation of the recipient site and allograft through various fixation options for securing the graft.

Soft-Tissue Meniscal Allograft Transplantation Technique

Hello, I'm Jim Carrey and I'm going to present a meniscus allograft transplantation using a soft tissue technique. So here I've planned the incisions for a meniscus allograft transplantation in isolation. So I've outlined where I was planning to put these incisions. This is the lateral portal. This is the medial portal, slightly enlarged to allow both the passage of the allograft and also some fixation along the joint line. This incision is also to allow for some fixation along the joint line. I plan for it to be a little anterior to where the saphenous nerve would be, but I still think this is in that nick and spread zone where you have to take great care to make sure you're not injuring that sensory nerve. And then this incision is for the posterior root fixation. That suture be drawn through the small tunnel and tied over a button here. Now of course, if this meniscus allograft transplantation is not in isolation, and you're performing some concomitant procedures. You might actually have a more midline longitudinal incision, like for an ACL reconstruction that you're harvesting. Bone patellar tendon, bone autograft or for cartilage repair where you're doing an arthrotomy or a mini arthrotomy. This procedure could be performed through one midline incision if it was a bit longer, but this is my typical preference for meniscus allograft transplantation and isolation. So I've established arthroscopic portals, and I found that this compartment is indeed severely meniscal deficient. I've even worked to remove the central meniscal tissue that was grossly torn and nonfunctional, so that there's just a one millimeter rim to act as a buttress to keep the new meniscus in place and to facilitate healing. Now, in order to prepare the Posterior horn. I did it in a standard way for the medial aspect for the body. I switched portals and worked to come across like this to bite that tissue to the one millimeter rim. The anterior horn is a little bit more of a challenge. I will tend to try to use the straight biters to reach across there. I'll even use the 90 degree. I can use it in the direction that you would think like in this case, a 90 degree to the right will allow me to open up and bite this tissue. Oftentimes for working on the top surface, the 90 degree going the other way and holding it upside down will allow better visualization as you're removing that tissue. Of course, you can use back biters as well, and shavers and any way you can resect that central tissue. So you just have that one millimeter rim. The next step is to prepare the posterior root attachment site. Sometimes it can be challenging to get instruments in through this area. And so through the medial portal I'll sometimes come across and trephining some of the deep fibers of the MCL to allow it to open up enough to perform this part of the procedure. Now that I have great visualization of that area, there are a few ways that you can prepare this back region. One way is to use a Curette. This is a ring Curette. Sometimes using a burr will work on that area or a shaver, but I'm trying to remove the cartilage overlying this attachment site, so that's part of it prepared. The advantage is you don't have to worry about trying to pass the suture through the meniscus. Arthroscopically you can do that outside the body. Of course, now that we've prepared the knee to receive the meniscus allograft will prepare the meniscus allograft. The first step I'll do is I'll look at where the meniscus attaches. Here's the posterior root attachment site that I prepared in the knee. And I'll mark it with my pen. And then when the meniscus falls on that tissue let me know right where I want my sutures to go in. So they're going to go in the bottom around there and then the anterior horn. Sometimes it can be a little tricky to determine where does the meniscus end. Where does the inner meniscal ligament begin? I think we can see in this case it's somewhere right about there is that junction. I'll take the knife. And just like in the knee, we left a residual one millimeter rim of the native meniscus. So for outside the knee. Now for the transplant tissue I'm going to remove that one millimeter rim so that it fits in nicely. And the sharpest scissors you have that are heavy should be employed for this part because it can be tough tissue to work with. And you have to watch your fingers as well as you're working on this tough tissue. I use the scalpel to make an incision through this tissue, and then I put the scissors in it and fold just the curvature. And most of these fibers run longitudinally along the meniscus, and they kind of keep you on the right track. And I'll do the same thing about the posterior horn where I put my scalpel through the tissue. And then I'm just going to let the fibers pull me along that plane. They always. All right. So now I've removed that peripheral one millimeter rim. You can see the residual meniscal tissue there. I'm going to return to that area that I marked for the posterior horn. I want the sutures to come right out the inferior surface, because that's what's going to draw it right down into that small tunnel for the posterior horn. I do use the pen to mark a boundary there. I don't want any of my suture to go more medial than that boundary, because I fear that it could abrade against the articular surface, and especially in deep flexion. And sometimes we'll even cause a squeaky noise. Then I'm planning the attachment site. So again the sutures should come right in the bottom. I'm going to mark a boundary that I don't want any of my sutures to go more medial than that boundary. And then for the posterior horn and the anterior horn, that will be the FiberWire suture. The posterior horn suture will go through the tunnel, be tied over a button. And then the anterior horn suture will be secured in with a biocomposite anchor. I also need to plan for the absorbable monofilament suture to help draw in the meniscus in the body posterior aspect of the body, but also it can be tied over the capsule, whereas these sutures come out the inferior surface. This one comes right out the periphery. And then I do one locking loop of suture. That helps grasp the tissue, and then I pass the suture towards the front without a lock. This is one of those things. If you believe your meniscal root repairs can be secured and that they have capacity for healing. And essentially, if your meniscal root repairs work, then you should believe that this works because it's the same principles, but you're placing the suture even more carefully in the tissue and ensuring the quality of the tissue. And with these passages and again, the suture ultimately comes out the inferior surface to draw it right into the tunnel. And then I'll do the same thing for the anterior horn. I'm coming through the inferior surface. I'm doing one locking suture. I'm sharing. It's a nice simple loop. I'll pass the suture from the peripheral aspect to the central aspect. Then I'll do another locking, and then I'll pass the suture out the inferior surface, because again, it's going to be drawn directly into the bone there. Now we have that suture coming out the inferior surface of the anterior horn. Now I'll pass the absorbable monofilament from the periphery to the central aspect. And then from the superior surface back to the periphery. Now you can see we have the posterior route sutures passed which come out the inferior surface. We have the suture near the junction of the body and posterior horn passed, which comes out the periphery, and then the anterior route sutures pass, which come out again the inferior surface. Now I'm going to free the meniscus from the bone. So I'll look at where the sutures come out, and I'll go immediately lateral to that. I'll do the same thing about the anterior horn. So now you can see the meniscus allograft is now freed. Now there are a few ways with rigid targeting guides you can access this area. One way is with this kind of smooth guide from the medial portal to go underneath. And I think that would work quite well in this case. Another way to do it is to switch portals and use a targeting guide that you may have commonly used for ACL reconstruction to access that area. And you can put the tip right in the attachment site and drill right to that point. So I found that this targeting guide is lined up nicely. And then if you are doing an ACL reconstruction at the same time, I take care to make the tibial exterior starting point of the tunnel more inferior than the opening of the ACL tunnel, so that the whole tunnel is more inferior than the ACL tunnel. So now I'm holding the rigid targeting guide so that the aperture of this small 2.4mm tunnel should come out in the attachment site of the posterior root, and then on the tibial cortex, the tunnel is at least two fingerbreadths distal to the joint line. And in fact many of these are with ACL reconstructions. I'll even go distal to the ACL tunnel. So now with this rigid targeting guide, we'll drill to the aperture of the tunnel. And then we can take the bullet out and we can pop the guide off. And we can see where this will come out. It's within the footprint that we prepared. So there is the tip of the guidewire 2.4mm right in the anatomic attachment site of the meniscus. And then we're going to remove that guide pin. And we're going to place this. Micro SutureLasso up. That path is coming out right within the attachment site. I will grab it and then through here we'll place a suture shuttle, and we're going to pass the tails so that we leave the loop out through the medial portal. Now the next step is to plan the suture that will come in near the junction of the body and posterior horn to help draw it in. So I'll bring one in about here. And this will be probably for the anterior part. This is one area where you have to take care, and you have to plan so you don't get a suture bezoar and a big nest of suture is that I'm looking at where the suture for the posterior route shuttle comes out. And I'm going superior to that through the same portal. And then I'm going to pass another loop of suture. This one we can do the tiger stripe white, maybe, and I'll pass the tails and I'll leave the loop out of the medial portal. We'll draw in that suture that is TigerWire, and I try to keep the TigerWire anterior and then purple posterior just so I keep them straight. Now I've passed the second SutureLasso posterior to the one with the stripes. And I'm grabbing that. Then we'll do another loop of bluish or purplish suture there. Now we're ready to draw in the meniscal allograft. Double check to make sure that the portal is big enough to bring the allograft in. You can check if your little finger fits in. Then usually it's enough for the meniscal allograft. And now we're going to insert the meniscus. The first thing I did was I placed the sutures from the posterior root through the loop of sutures that goes through that posterior root tunnel, and we're going to shuttle that in place. After that's placed, I clamp that with a hemostat. And then everyone can relax a little bit because now the meniscal transplant is unlikely to fall out. The next step is to pass the sutures for the posterior and the anterior limbs that are passed through the body of the meniscus, the the posterior one. We kept track of posterior bluish in this case. And then we took care to try to minimize the risk of these getting tangled. And now we're passing the meniscus into the knee. So one of the important things that I check is to make sure that this is a simple connection right from the periphery of the transplant, right to that residual rim and capsule. Sometimes the sutures can get caught or soft tissue about the portal, or can even get looped around these posterior horn sutures. But in this case, you can see where the posterior root sutures go in, and we can pull tension about the body of the meniscus. Now I'll tie down the posterior horn over a button. So here is the metallic button that I have the suture pass through. I'm going to tie down the suture over the button. And then this will secure the posterior root. And then I secured it with about four throws of suture. If for some reason you notice later that it's loosened, it's easier to undo 3 or 4 throws than it is eight throws. And then you can retighten it again. So that's the only reason I didn't do more. Take a look at it. Arthroscopically. So now I'm checking the posterior root is secured and opposed to the bone there, as it should be. Next I'll tie down that suture medially that we use to shuttle the graft in place. And I'll take a look in. Just gives us a sense of what the meniscus will look like when it's secured. And now we'll use the all-inside repair devices to secure it to the posterior rim of residual meniscus. So for securing the posterior horn, I've placed this skid above the superior aspect of the meniscus. And then I'm going to use an all-inside repair device. So now we're going to secure the posterior horn with an all-inside technique. I'm going through about the center of the transplant tissue. And this tissue is very tough again. So I'll do little micro wiggles to get through it. Now I'll try to plan this so it's a diagonal. Not purely horizontal. Not purely vertical. And then. So now we get to see the the route again was tied over metallic button. This was the absorbable monofilament which is just tied on the other side of this tissue on the other side of the capsule. And this was an all inside meniscal repair. And I'll check make sure that all of those feel secure. You can see too, as you imagine these sutures being tightened, that some of the wrinkles come out. I don't treat this flounce at all along the way. I don't trim the meniscus, for example. Usually that just settles out. All right. Now we have one more hard part, which is passing this suture from outside to in. The first one can be hard because you're pushing through the capsule and you're pushing in. And then usually the second one, once the first one is pinned, is easier. For one loop through the other and pull it through. And we'll use that to shuttle in another one of these The absorbable monofilaments. That will pass that. And then this one I'm going to back out a little bit and then I'll pass that. All right. Well after doing that all inside repair of the posterior horn then we did an outside in repair in the body. You can see the meniscus is starting to line up. Well it's starting to feel like it's well secured. And the next step is going to be securing down the anterior horn. And for that we're going to use a biocomposite anchor. The first thing I'll do is I'll plan where I want this to attach. And it's usually right by the anatomic attachment site. I like to make the hole first with the awl, and then I use the curette to clear off some of the cartilage overlying the whole, especially on the medial side of the whole. All right. So there's the attachment site that I have planned for this anterior root. So here's the anchor for the anterior horn. And I'm looking at how the other tissues lining up. That will show back that out. And it shows there's the anchor well secured test and a tug. Usually these are carefully sized matched by uploading MRIs to a central database and finding the right size. This one was just was slightly larger than the recipient knee, but it still fits in quite nicely. After placing the anchor that secured the anterior root, I then went back and placed another suture in the anterior horn to help secure it using the ZoneNavigator system. And that is an inside out repair, which made it a little easier in this case, because when you're pushing from the outside in, you need to hold resistance, you need to hold to counter pressure. But when you go from inside out, of course it's a little easier because you're just pushing the meniscal tissue into the residual meniscal rim. So then at this point, I'll go back and evaluate the entire meniscus, all the fixation points, and make sure it's entirely stable. And then for the postoperative rehabilitation protocol For these meniscal transplants. I worry about the root healing, and so their weight bearing is protected for a period of six weeks. They use crutches, they have motion limits and a hinged knee brace that limits their flexion to 70 degrees for the first three weeks. During that time period, I worry about the rollback mechanism of the knee as the femur rolls back, could stress out the posterior horn and root repair too early. After six weeks, all of those precautions are lifted. There's no more motion limits. Weight bearing precautions, crutches or a brace. And then they start to increase their activities. They first ensure they get full motion and then strengthening. Then after that they resume normal function around 18 weeks. Post op would be the soonest we would clear someone for return to sporting activities.

Meniscus Transplantation

Segmental Meniscus Transplant

Dovetail/Slot Meniscal Transplant Technique

Double Bone Plug Meniscal Transplant

Soft Tissue Meniscal Allograft Transplantation Technique