the medial meniscus. In Klingele KE, Kocher MS, Hresko MT, et al. Both the healed peripheral tear and the new central tear were proved at second look arthroscopy. 2006; 187:W565568. Of the 45 patients who were interviewed and evaluated clinically without surgery at a minimum of 1 year, 32 reported continued pain but no mechanical symptoms suggestive of a meniscal tear. A new longitudinal tear has occurred more centrally in the meniscus (arrowhead) with linear high signal extending to the tibial and femoral surfaces as well as fluid signal and gadolinium contrast in the defect. We use cookies to create a better experience. Evaluate the TCO of your PACS download >, 750 Old Hickory Blvd, Suite 1-260Brentwood, TN 37027, Focus on Musculoskeletal and Neurological MRI, Meniscal tears: the effect of meniscectomy and of repair on intraarticular contact areas and stress in the human knee. Sagittal PD (. The intrameniscal ligament where it diverges from the back of the anterior horn of the lateral meniscus is also a common area misinterpreted as a tear. The meniscal repair is intact. MRI of the knee is commonly indicated for evaluation of unresolved or recurrent knee pain following meniscal surgery. View Mostafa El-Feky's current disclosures, see full revision history and disclosures, Flipped meniscus - anterior horn lateral meniscus, Disproportionate posterior horn sign (meniscal tear). Magnetic resonance imaging (MRI) and computed tomography (CT) arthrography are both well suited for evaluation of these lesions though somewhat limited by cost and access for MRI and by invasiveness for CT arthrography . The ligament of Humphrey inserted on average 0.9 consecutive images lateral to the PCL without an PHLM tear and 4.7 with an PHLM tear; the ligament of Wrisberg inserted on average 3.0 consecutive images without an PHLM tear and 4.5 with an PHLM tear . Rohren EM, Kosarek FJ, Helms CA. Kim EY, Choi SH, Ahn JH, Kwon JW. This arises from the posterior horn of the lateral meniscus and attaches to the lateral aspect of the medial femoral condyle. does not normally occur.13. Posterior meniscal root repairs: outcomes of an anatomic transtibial pull-out technique. Thirty-one of these patients underwent subsequent arthroscopic evaluation to allow clinical correlation. pivoting). 2014; 43:10571064, McCauley TR. Symptomatic anomalous insertion of the medial meniscus. Concise, to-the-point text covers MRI for the entire musculoskeletal system, presented in a highly templated format. On MR images of the knee it is sometimes impossible to determine with confidence if a focus of high signal in the meniscus is confined to the substance of the meniscus or if it extends to involve the surface. discoid lateral meniscus is a relatively uncommon developmental variant . Bilateral hypoplasia of the medial meniscus has also been You can use Radiopaedia cases in a variety of ways to help you learn and teach. Proper preoperative sizing of the allograft is critical for surgical success and usually performed with radiographs. Meniscal surgery is common and requires accurate post-operative imaging interpretation to guide the treatment approach. is affected. The ends of the anterior and posterior horns are firmly attached to the tibia at their roots. 2. The anterior horn of the menisci, especially the lateral meniscus, is an area commonly confused on MRI. tear. It has been calculated that the lateral meniscus absorbs about 70% of the forces across the lateral compartment of the knee. 4. Repair of posterior root tears are being performed with increased frequency over the past several years. When it involves the posterior root, medial root tears are easier to diagnose than lateral root tears. Presentation - Middle-older aged individuals, non-traumatic, progressive onset of pain. It is possible that there could have been some tears missed at arthroscopy that were on the undersurface of the anterior horn, an area which is extremely difficultif not impossibleto visualize. show cupping of the medial tibial plateau, proximal medial tibial physis In cases like this, MR arthrography is quite helpful. The medial meniscus covers 60% of the medial compartment. Of these patients treated nonoperatively, 6 had a diagnosis of an isolated anterior horn tear on MRI. The medial meniscus is more firmly attached to the tibia and capsule than the lateral meniscus, presumably leading to the increased incidence of tears of the medial meniscus [ 8, 11, 12 ]. The patient had a recent new injury with increased pain. rim circumferentially, anteriorly, and posteriorly,19 which The lateral meniscus is more circular with a shorter radius, covering 70% of the articular surface with the anterior and posterior horns approximately the same size. published a case series of anterior horn tears of the lateral meniscus in 14 soccer players (mean age 20.2 years). A tear of the lateral meniscus can occur from a sudden injury, or from chronic wear and overload. Radial or oblique tear congurations close to or within the meniscus . However, this conjecture and others pre- highest.13,27,34,42 Tear locations, such as the posterior sented in literature are mostly speculative. If a horizontal tear involves a long segment of the meniscus, the central fragment may displace centrally from the peripheral portion of the meniscus [, Bucket handle tears (BHT) often cause pain and mechanical symptoms, such as locking, catching, and giving way [. Vertical flap (oblique, flap, parrots beak) tears are unstable tears and occur in younger patients. Radiology. Of the 54 participants, 5 had PHLM tears and 49 were normal. MRI appearance of Wrisberg variant of discoid lateral meniscus. Long-term outcome after arthroscopic meniscal repair versus arthroscopic partial meniscectomy for traumatic meniscal tears. MR criteria for discoid lateral menisci are used for discoid medial Tear between 1-4 cm vertical tear red-red meniscal root <40 yo Maybe concominant ACL surgery . Dickhaut SC, DeLee JC. Following meniscal allograft transplantation (Figure 17), complications occur in up to 21% of procedures, including allograft failure and progressive cartilage loss.19 Repeat operations occur in up to 35% of patients, 12% requiring conversion to total knee arthroplasty. Comparison of Postoperative Antibiotic Regimens for Complex Appendicitis: Is Two Days as Good as Five Days? There Findings indicate an intact meniscus following partial meniscectomy with normal intrameniscal signal. A slightly overweight 44-year-old male sought evaluation for medial knee pain that persisted for months after running on the beach. Tears in the red zone have the potential to heal and are more amenable to repair. Intact meniscal roots. A recurrent tear was proved at second look arthroscopy. of the anterior horn of the medial meniscus, an inferior patella plica, Heron, D, Bonnard C, Moraine C,Toutain A. Agenesis of cruciate MRI showed posterior horn of the medial meniscus (PHMM) horizontal tear with early degenerative changes. Development of the menisci of the human knee There are 3 main types, according to the Watanabe classification:18. The incidence of lateral meniscus posterior root tears was approximately 4 times higher than of medial meniscus posterior root tears in both primary (12.2% vs 3.2%) and revision (20.5% vs 5.6%) ACLRs. 2020;49(1):42-49. Conventional MRI is useful for evaluation of posterior root morphology at the tibial tunnel fixation site, meniscal extrusion and articular cartilage. There was no evidence of meniscal extrusion or a meniscal ghost sign (Fig. medial meniscus, discoid lateral meniscus, including the Wrisberg However, the use of MRI arthrography should be considered for post-operative menisci with equivocal findings on conventional MRI as the presence of high gadolinium-like signal within the meniscus would allow for a definitive diagnosis of re-tear. An intact meniscal repair was confirmed at second look arthroscopy. This scan showed a radial MMT. varus deformity (Figure 3). An alternative way of fastening the allograft to the donor knee involves harvesting the meniscus with a small bone plug attached to each root and then securing the plugs within osseous tunnels drilled in the recipient tibia. {"url":"/signup-modal-props.json?lang=us"}, El-Feky M, Flipped meniscus - anterior horn lateral meniscus. ligament and meniscal fascicles. Mucinous degeneration of meniscus can also produce abnormal signal within a meniscus which does not contact an articular surface and should not be mistaken for a tear. The congenitally absent meniscus appears to influence the development Close clinical correlation is advised before recommending surgery based on this finding alone. On MR arthrography, (12B), gadolinium extends through the repair site indicating a tear. Shepard and colleagues at UCLA specifically analyzed this by reviewing 947 consecutive MRIs. Sagittal proton density-weighted image (5A) through the medial meniscus at age 12 shows the initial horizontal tear in the posterior horn (arrow) subsequently treated with partial meniscectomy. Laundre BJ, Collins MS, Bond JR, Dahm DL, Stuart MJ, Mandrekar JN: MRI accuracy for tears of the posterior horn of the lateral meniscus in patients with acute anterior cruciate ligament injury and the clinical relevance of missed tears. There is a medial and a lateral meniscus. Davidson D, Letts M, Glasgow R. Discoid meniscus in children: Treatment and outcome. 9 The lateral meniscus is more loosely attached than the medial and can translate approximately 11mm with normal knee motion. The medial meniscus is asymmetrical with a larger posterior horn. History of medial meniscus posterior horn partial meniscectomy. This is a well-done study with clinical correlation and adequate follow-up. posterior horn usually measures 12 mm to 16 mm in the sagittal plane in Sometimes T2 signal in a healed tear may look similar to fluid. The anterior and posterior sutures are shuttled down the tibial tunnel (arrowhead). The insertion site posterior horn of the medial meniscus include a triangular hypointense The most important clinical concern at the time of MRI imaging is often high-grade articular cartilage loss. Stein T, Mehling AP, Welsch F, von EisenhartRothe R, Jger A. American Board of Orthopaedic Surgery Practice of the Orthopaedic Surgeon: Part-II, certification examination case mix. Check for errors and try again. During an arthroscopy, we have the choice of either repairing the meniscus tear or removing the torn piece. variants of the meniscus are relatively uncommon and are frequently Type 1: A complete slab of meniscal tissue with complete tibial coverage. The posterior horn is always larger than the anterior horn. The symptoms They often tend to be radial tears extending into the meniscal root. This article focuses on CT arthrography is a recommended alternative for patients who are not MR eligible. Discoid lateral meniscus. Congenital discoid cartilage. A classification system developed by the International Society of Arthroscopy, Knee Surgery, and Orthopedic Sports Medicine [, Longitudinal-vertical tear. problem in practice. 2008; 32:212219, Magee T. Accuracy of 3-Tesla MR and MR arthrography in diagnosis of meniscal retear in the post-operative knee. Choi S, Bae S, Ji S, Chang M. The MRI Findings of Meniscal Root Tear of the Medial Meniscus: Emphasis on Coronal, Sagittal and Axial Images. Type 1 is most common, and type Magnetic resonance imaging (MRI) revealed an elongated free edge of the diffusely enlarged lateral meniscus extending toward the intercondylar region on coronal T1-weighted images (Figure 1A). One of the most frequent indications for arthroscopic knee surgery is a meniscal tear.1 It is estimated that 1 million meniscus surgeries are performed in the U.S. annually with 4 billion dollars in associated direct medical expenditures.2 Meniscal surgeries include partial meniscectomy, meniscal repair and meniscal replacement. An abnormal shape may indicate a meniscal tear or a partial meniscectomy. no specific MR criteria for classifying discoid medial menisci, and the Kaplan EB. collapse and widening of the medial joint space (Figure 7). If the tear does not show, it is considered a Grade 1 or 2 and is not as serious. 2012;199(3):481-99. 36 year old male with history of meniscus surgery 7 years ago. About KOL ; Learn more about our technology and how more and more universities, research organizations, and companies in all industries are using our data to lower their costs.