Hi, thank you for this opportunity. My name is Cliff Willeman, and I would like to share with you technical pearls for meniscus root repair. The meniscal roots serve to anchor the meniscus to the tibia and act as secondary strengths to anterior-posterior translation rotation. Root tears are characterized as avulsions of the attachment or a complete radial tear within one centimeter of the meniscal insertion. Injury to the root can result in extrusion of the meniscus, impaired hoop stresses, or degenerative articular wear. Thus, this has increased emphasis on repair to restore structure and function. The root anatomy is an important consideration. Using the tibial spines as landmarks, the medial meniscus posterior root attaches over a centimeter away from the apex of the medial tibial eminence. In contrast, the lateral meniscus posterior root attaches much more closely to the apex of the lateral tibial eminence, as well as to the anterior horn lateral meniscus root. Posterior root medial meniscus is anterior to the PCL tibial attachment, but we often see these in conjunction with PCL injuries as almost a sleeve-type injury. The diagnosis of a root tear is characterized by the patient reporting more vague posterior knee pain, worse with deep flexion, and joint line tenderness. In non-traumatic injuries, the McMurray's may be positive in half the cases, and the patients may present with an effusion. MRI is certainly helpful, and we see in each plane of view a characteristic finding. On the sagittal view, we can see the ghost sign. On the axial view, we'll see the frank defect of the missing tissue, and on the coronal, you may see extrusion in more chronic cases. Here are representative images of that. In the coronal view, we can see the lack of root attachment of the posterior root of the medial meniscus. In the middle, in the sagittal view, we can see the absence or ghost sign of the root of the medial meniscus posterior horn. And then lastly, on the axial view, we can see the defect. Leprod has provided a classification system for these injuries, with type 1 being a partial root tear. Type 2 being a complete radial tear of the root, modified with a measurement of the length of the root or distance from the root to the tear. Type 3 is a root tear associated with a bucket handle tear. Type 4, also a common tear we see, is an oblique tear into the root attachment. And type 5, a root avulsion fracture, or sometimes these are more of a periosteal avulsion in pediatric patients, a quite common pattern we see. Root tears are indicated for acute traumatic tears. Most commonly, lateral root tears are associated with ACL injuries, or medial injuries are associated with multiligament knee injuries. You can see chronic symptomatic root tears without significant arthritis, certainly are eligible candidates for repair. And root repair is contraindicated in those tears in which they're irreparable due to chronicity or to absence of tissue, or possibly in the lateral meniscus posterior root tear with an intact ligament or risk burden. There's certainly lots of ongoing discussion whether that provides adequate stability or not. So preoperatively, it's important to anticipate the root tear. This is best done by a careful review of the MRI, because you don't use the usual meniscus repair instrument. So anticipating it to have the appropriate tools necessary, as well as it's nice to prepare the patient family for the possibility of a root repair, because it significantly changes the postoperative weight-bearing timeline. Trans-osseous root repair is performed using a sequence as follows. First, making the diagnosis, probing the meniscus, and then mobilizing the meniscus. Typically in acute injuries, there's not much retraction, but in more chronic injuries, you may have to dissect the root away from the posterior capsule. This can be done through the notch or through an accessory posterior medial or posterior lateral portal. You can use a curved curette to prepare the root attachment site. So you have a fresh bony bed, and then you can use either two independent trans-tibial tunnels using cannulated guide pins or a single socket of six millimeters in diameter. Next, a braided non-absorbable suture. Now we have suture ribbons or tapes that can be used for additional surface area can be passed through the root. This is typically done through an all-inside suture passing instrument as shown in the bottom middle picture. But if there was not adequate access, you could pass these using a suture shuttling device through an accessory posterior medial or lateral portal. Two simple sutures or a modified Mason-Allen stitch have been shown to both resist displacement better than a single locking loop. And then these sutures are shuttled through the tibia and tied over a button on the intermedial tibia with the knee at 90 degrees of flexion. Additional biomechanics studies have shown tying these over just a bony bridge results in further creep. So using a button does seem to be beneficial. Post-operatively, the patients are non-weight-bearing for six weeks. In week seven, allow them to weight-bear 50% and then in week eight, use one crutch. Use a knee immobilizer or a hinged knee brace lock with an extension for six weeks. Range of motion is limited to zero to 90 degrees for the first four weeks and advanced as tolerated. Typically then begin physical therapy one to three days following surgery and return to sport is guided by concomitant ligaments reconstruction such as ACL at nine plus months or if an isolated root repair, five to six months from surgery. I typically advise the patients to avoid deep squats for the first three to four months given the increased pressure on the root repair site. A bit about outcomes. Phil Wilson and Henry Ellison team have reported on the instance and presentation of pediatric and adolescent meniscal roots. They described a group of patients of 58 posterior meniscal root injuries at mean age of 16. 83% of the patients were scaly mature and the majority were non-contact injuries associated with ACL tears. The patients exhibited a variety of symptoms including joint line tenderness and infusion, decreased range of motion. Meniscal extrusion was not common and was seen on one third of MRIs. Again, more consistent with the acute injury versus the chronic injuries of the roots that we see in middle-aged patients. Lateral meniscus root tears are more commonly the prod type twos and type fours and medial meniscus root tears are more commonly type fives with the avulsion injuries. LeProd has published his series on root repairs in adult patients ranging from ages 18 to 65. The patients were grouped based on age and less than 50 or more than 50 years of age. Majority of these were medial meniscus root tears. Again, more consistent with the age-related degenerative type tears. Their mean fault was two and a half years and this provided one of the earlier series to report on outcomes. The most common injury pattern in his adult series was a complete radial tear. The patients with the lateral meniscus root repair had eight times odds of having a common ACL reconstruction. Again, the lateral root and the ACL being highly associated. Among their knees with minimum two-year follow-up, three or 6.7% of patients had a revision root repair and all the functional scores in the patients had significant improvements. And there was no difference in the functional score improvement based on age cohorts or medial or lateral meniscus root injury. So in conclusion, meniscus root injuries in young patients are most commonly acute avulsions of the posterior root of the lateral meniscus and occur in association with ACL tears. So scrutinize and review them or eyes closely. This is in contrast to the isolated chronic degenerative posterior medial meniscus root tears we see more commonly in middle-aged adult patients. It's important to inspect and probe the meniscus roots during every knee arthroscopy. The avulsions can be quite subtle and they are not well visualized until you challenge the tissue integrity by probing it. And then overall trans-osseous root repair seems to result in high patient satisfaction rates and superior outcomes to meniscectomy for meniscus root tears. Thank you.

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