4 Top Sports Docs Tackle Tendon and Ligament Repair

Ligament or tendon repair is both the bread and butter of sports medicine and one of its most interesting and debated subjects. At the 2018 Orthopaedic Summit of Evolving Technologies, held in Las Vegas this past December, four of the most accomplished sports medicine surgeons—John Xerogeanes of Emory Orthopaedic and Spine Center, Charles Brown, Jr. of International Knee & Joint Centre, Akbar Nawab of University of Louisville Department of Orthopedics and Christopher Kaeding of Ohio State University—gave a master class on this essential subject.

The moderator who kept each speaker’s feet to the fire was Charles A. Bush-Joseph, M.D. of Rush University Medical Center.

John W. Xerogeanes, M.D. was first up, and his point of view could best be described as: “Quad Tendon Grafts are the Answer: Why Are You so Slow to Jump on Board!”

John W. Xerogeanes, M.D.: I’m talking about soft tissue quad tendon. I just finished my 1,000th one. Prospectively followed, the mean age of these patients was 20.1 years, median age 17.6 years and we experienced about a 4.2% failure rate of the ones we followed.

In terms of revisions, I have done 96 revisions using quad tendons. Here the mean patient age was 22.5 years, graft failure was about 4.8% and the side effects KT and IKDCs [International Knee Documentation Committee Subjective Knee Evaluation Form Score] were similar to our primaries.

Also, our historical outcomes of soft tissue grafts quads versus the others are fairly similar.

Why don’t people do it? I think it’s because people don’t understand it.

Consider the biomechanics. A 10 mm width graft is significantly stronger than a patellar tendon, but the modulus is very similar to the native ACL [anterior cruciate ligament]. If you harvest a 10 mm graft, the residual quad tendon remaining is still significantly stronger than an intact patellar tendon.

Also, predictability. With hamstrings, it’s always hard to get in there and get a little wispy hamstring and then the big guy and then you have to do a five- or six-string technique. We developed a 3D MRI technology and compared quads to hamstrings and quads to patellar tendon.

The tip of the rectus femoris to the superior aspect of the patellar graft is greater than 7 cm in 90% of people over 5 feet tall. The thickness is 1.8x the thickness of the patellar tendon and there’s minimal variation over the last 6 cm of the quad tendon.

The average ACL is 2.5-3 cm. So, your graft needs to be 6-7 cm because you put 2 cm in the femur, 3 cm in the joint, 2 cm in the tibia.

What about the intra-articular volume? If we take a 10 mm width graft 3 cm long and compare that to a patellar tendon, the only variable is thickness. Remember, it’s 1.8 times thicker. You’re getting 88% more volume of tissue that is biomechanically and histologically superior to patellar tendon.

What about kids? The average kid has a 3.2 mm thick tendon. His quad is as thick as your adult patellar tendon.

What about morbidity? You don’t get any numbness. Patellofemoral pain is minimal. Any residual weakness is not normal. Other morbidities would include quad weakness, tendon ruptures, patella fractures. You do get hematomas like with anything else, but the pain is significantly less than other two.

Harvest time. It takes me about 25 minutes for patella, 13 minutes for hamstring, and under 8 minutes for a quad.

How do I get it? You don’t want to get a big huge scar. We changed the transverse and you can barely see it.

So, is it the perfect autograft? It’s superior histologically, biomechanically, predictably, superior size, good for all ages, equal or superior outcomes, least morbidity, fastest harvest, in percutaneously, cosmetic is definitely superior.

Don’t be afraid. Try it.

Charles H. Brown, Jr., M.D. “The 5- and 6-Strand Hamstring Tendon ACL Graft”

I’m going to switch gears and talk about hamstring tendon grafts.

Hamstring graft size does matter. Increasing the diameter of your hamstring tendon graft decreases revision and failure rate.

Reconstructions with grafts larger than 8 mm decrease the failures rate. Four-stranded graft is your traditional doubled gracilis and double SemiT [semitendinosus]. Four-stranded, I stopped in 2007.

We developed five- and six-stranded graft techniques.

Now we use about 90% six-stranded grafts. The five-stranded graft is a triple SemiT and a doubled gracilis. Typically, the femoral side is an average 8 mm. The tibial side is 8.5. If you use the technique I describe, you get a larger tibial end than femoral end. The six-stranded graft is a triple semitendinosus and triple gracilis and you can get 9 mm on the femoral and sometimes 9.5 on the tibia.

In your four-stranded graft, the diameter is 8 on the femoral side 6-7 on the tibial side. The distal end of the graft is attached to 5 mm Dacron tape. It’s the width of the tape that matters. The tape does not add to the strength of the constructs but still helps to compartmentalize the grafts. Tie the distal end of both the gracilis and the semitendinosus. You should use a high-strength suture. Proximal end is tied to a suspensory device.

Use an endobutton 15 mm fix loop. Tie this as hard as you can. The proximal end of the graft of the hamstring should be tied to the loop. Tie that to the loop and then tie the sutures from gracilis to semitendinosus together.

This gives you a continuous loop of hamstring graft. So, both grafts are now attached to the endobutton. Now the distal end is passed through the loop of the endobutton inside out and there is a loop through a loop. The distal end is passed through the loop you create and that triples the graft. The tape compartmentalizes the third strand, keeps it from falling out of the loop.

On the other side, the gracilis is doubled and now you have a six-stranded graft. It’s important to try to equally tension the graft so you can apply uniform tension.

Now the diameter is up from 8 mm to 11 mm on the tibial end and 10 mm on the femoral end. You’ve taken a small graft and significantly increased the diameter by doing this technique. Typically, you need about 25mm.

Tips: use a high strength of suture to whipstitch the ends. Polyester suture may break. Attach the proximal end to the loop and the distal end to the tape. This results in the tibial end being larger than the femoral end. A 24 cm length hamstring graft will allow adequate length. 25 for the femoral socket, 25 for the intra-articular length of the graft, and 30 mm for the tibial.

Data from ACL registry suggests higher infection rates for hamstring tendon autografts. The Vancomycin technique was introduced in Australia in 2008 has 0% infection. Four-millimeter gauze and 500 mg of Vancomycin. Wrap it and create a burrito and that decreases your infection rates.

In summary, hamstring grafts with a diameter of 8 mm or greater have lower failure and revision rate. Five- and six-stranded hamstring tendon grafts allow the surgeon to create a larger-diameter hamstring grafts compared to traditional four-stranded graft.

Moderator: We do have a quick question from the audience for Dr. Xerogeanes: (1) Do you ever use bone block? and (2) what do you use for fixation on your graft ends?

Dr. Xerogeanes: I have used the bone block, but that’s usually in revision settings. If I need bone in fixation I tie over post old school on the tibia and proximally use an adjustable loop button.

Dr. Johnson: Dr. Xerogeanes, any worries about taking the quad tendon after I’ve taken their patellar tendon? You know Darren Johnson’s already taken their patellar tendon.

Dr. Xerogeanes: In most of those revisions that you saw, I’d say at least half of them were patellar tendons. With that being said, I would never take a quad tendon with a bone block.

Akbar Nawab, M.D. “The Anatomic Ribbon ACL Surgery”

To understand this ribbon concept, you really have to understand the footprint of both the femur and tibia. On the femoral side, there are direct and indirect fibers. Direct fibers inserted along resident’s ridge are in line with the posterior cortex. Direct fibers have a deeper staining tidemark implying some increased stress concentration across this area. Indirect fibers insert lower on the notch and are a fan-like extension of fixed fibers.

The tibial side has a crescent-shape footprint. It forms around the anterior horn of the lateral meniscus. The division of this was mostly along the C-shape, but other morphologies were noted as well.

The problem is, at the time of surgery, it hardly looks like a ribbon or any form of a ribbon. We see this after there’s been significant trauma. I went to the lab and atraumatically as possible divided the mid-substance of the ACL to see it.

I took the time during one of the surgeries to actually go through and look at the tibial footprints. You can see the anterior horn of the lateral meniscus and the J-shaped insertion and footprint just behind the anterior horn of the medial meniscus.

How do you do it? Obviously, you need some specialized instrumentation to make a slot on the femur in a crescent shape on the tibia. It requires some form of a flat graft in order to conform to the tunnel anatomy and you can use standard fixation.

Options for this. You can take a round tendon and split it and make it into a flat tendon or you could do something that’s been described earlier: either a patellar or quad tendon. If you take a round tendon and then divide this, you have no loss of graft integrity.

On the tibia, it’s a specific guide over which similar guide pins are passed followed by reamers and then a crescent-shaped dilator to form the tibial footprint.

What we’re trying to accomplish is a graft that shows the anterior fibers slightly tauter than the posterior fibers in flexion. Then as we get towards extension, around 20 degrees, we start to see differential tension occur in the posterior fibers. That is really what your native ACL does.

In conclusion, there’s been substantial evidence to support the ribbon anatomy to the ACL.

Authors have described the torsion of the ligament. I think it’s a very good explanation to marry the bundle concept with the ribbon concept. Footprints are very specific and I would question you: Are you really doing an anatomic ACL if you’re not recreating the anatomy of the footprint in order for the reconstructed tissue to do what the native ACL does.

I would ask you to question yourself, and as your children open their presents and toss all these ribbons to the floor, for you to convince yourself that the ACL is a ribbon. Take the time in surgery to do this. Go to the lab and convince yourself.

Christopher C. Kaeding, M.D. “Bioabsorbable Versus Titanium ACL Interference Screws: Want Some Facts?”

What about metal screws vs. bioabsorbable screws?

The advantage of a metal interference screw is it can promote early integration of the bone graft into bone, it has higher initial fixation strength than other methods.

The cons of a metal interference screw are that it does produce an artifact on MR imaging, it can make revisions more difficult, it gets in the way, it can be difficult to remove. Once you remove it, it can leave a large bone void. If you’re not careful when you place your interference screw, you can advance your graft into your tunnel and loosen your graft. It’s also been reported these screws can cause graft laceration.

What about bioabsorbable interference screws? These are designed to absorb over time and be replaced by bone in two and three years. That’s in theory. It’s been widely reported that incomplete absorption and delayed ossification can exist beyond 5 years. These are composed typically of PGA [polyglycolic acid], PLA [polylactic acid], or most commonly a polymer hybrid of those two. More recently, bio-composites have been developed to increase bone incorporation with increased osteoconductive properties.

The pros of a bioabsorbable screw are easier revision and decreased artifact on MRI imaging. The cons are you have less fixation strength, it may break during insertion. Incomplete resorption or incorporation to the bone can lead to tunnel widening, a bony cyst, and migration.

What about usage? In an international survey in 2013, almost three times as many surgeons were using bioabsorbable screws as metal interference screws.

What about fixation? Nyland in 2015 showed different bioabsorbable screws showed similar fixation characteristics and metal screws had higher mean insertion torque and mean load to failure. Pena showed that both metal and screws had similar mechanisms of failure.

What about complications of metal vs. bio screws? Laxdal in 2006 showed that bio screws had significantly larger radiographic appearance of bone tunnels on the femoral and tibial sides at 6 and 24 months. Myers showed that bio screws had increased femoral tunnel width.

What about clinical outcomes? You see very little difference.

If you look at meta-analyses and the Cochrane reviews, you have to conclude there’s no difference between metal and bio screws in IKDC scores, Lysholm scores, KT arthrometry, pivot-shift testing, or Tegner activity scores.

In conclusion, metal and bio screws both provide good fixation. There’s some increase risk of complications in bio screws, implant failure from breakage, persistent knee effusion and tunnel widening, but no difference between metal or bio screws in patient-reported outcomes or functional outcomes.

Personally, I do use bio screws in the tibia. With careful technique, screw breakage has not been a problem for me. I avoid any intra-articular exposure of the screw. I don’t think these bio screws should be exposed any kind of synovial fluid. Hence, I do not use them for retrograde femoral fixation. I have had the rare subcutaneous cyst which is responded well with excision.

Moderator: What about for the revision ACL? Do you like to see plastic screws there or do you like metal screws there?

Dr. Keading: The plastic screw, if it’s not an absorbable screw, it’s got the same issues the metal screw does. In revision, the plastic screw can be more difficult to find and locate…

Moderator: Bioabsorbable or metal?

Dr. Keading: In hamstrings, I don’t use an interference screw, I use cortical suspension. In the tendons, in the tibia, I use a bioabsorbable screw.

Please visit https://orthosummit.com/ for more information on this year’s upcoming event on December 11-14, 2019 at the Bellagio in Las Vegas, Nevada.