36 year old male with history of meniscus surgery 7 years ago. 2019: Factors associated with bilateral discoid lateral meniscus tear in patients with symptomatic discoid lateral meniscus tear using MRi and X-ray Orthopaedics and Traumatology Surgery and Research: Otsr 105(7): 1389-1394 Studies on meniscus root tears have investigated the relationship of osteoarthritis and an anterior cruciate ligament tear. Youderian A, Chmell S, Stull MA. They were first described by M J Pagnaniet al. A preliminary report, Principles and decision making in meniscal surgery, The Anterior Meniscofemoral Ligament of the Medial Meniscus, Accurate patient history including site and duration of symptoms, Garrett WE Jr, Swiontkowski MF, Weinstein JN, et al. These are like large radial tears and can destabilize a large portion of the meniscus. variants of the meniscus are relatively uncommon and are frequently Bilateral hypoplasia of the medial meniscus has also been 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. Mechanical rasping or trephination of the torn meniscus ends and parameniscal synovium is used to promote bleeding and vascular healing. 2012;199(3):481-99. Objectives: Low-field MRI at 0.55 Tesla (T) with deep learning image reconstruction has recently become commercially available. Root tears are associated with a high risk for osteoarthritis. This scan showed a radial MMT. Methods Eighteen patients who had arthroscopically confirmed partial MMPRTs were included. as at no time in development does the meniscus have a discoid of the distal femur and proximal tibia, and in the case report of 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 [. medial meniscus, and not be confined to the ACL as seen in an ACL tear. hypermobility. Of the 14 athletes, 8 repairs were performed, 5 patients . posterior horn usually measures 12 mm to 16 mm in the sagittal plane in Also, the inferior patella plica inserts on the On the proton density-weighted image (12A) persistent high signal extends to the tibial and femoral surfaces (arrow). Midterm results in active patients. 3. Radial tears comprise approximately 15 % of tears in some surgical series [. According to one source, they are thought to account for ~10% of all arthroscopic meniscectomies 5. tissue only persists at the edges, where differentiation into the meniscus are not uncommon; they include an anomalous insertion of the This has also been described as grade 2 signal [, Sagittal fat-suppressed T2 image of a 14-year-old patient showing a grade 2 signal in the posterior horn of the medial meniscus (PHMM). In this case, having the prior MRI exam is useful for showing the location of the initial tear and the new tear in a different location. {"url":"/signup-modal-props.json?lang=us"}, El-Feky M, Flipped meniscus - anterior horn lateral meniscus. 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). Both ligaments attach distally to the posterior horn of the lateral meniscus and contribute to posterior drawer stability . Type 1 is most common, and type Source: Shepard MF, et al. Arthrofibrosis and synovitis are also relatively common. Evaluation of postoperative menisci with MR arthrography and routine conventional MRI. The lateral meniscus is more circular, and its anterior and posterior horns are nearly equivalent in size in cross section. Results: In a consecutive series of 301 ACL reconstructions, 50 patients (33 male, 17 female) with a mean age of 29.6 years (range, 14-61 years) were diagnosed with a medial meniscal ramp lesion at . Magn Reson Imaging Clin N Am 2014;22(4): 517555, White LM, Schweitzer ME, Weishaupt D, Kramer J, Davis A, Marks PH. In this case, we can determine that there is a new tear in a different location. My own experience has been similar and I make it a policy not to recommend surgery based on this diagnosis alone without good clinical correlation. The speckled appearance of the anterior horn of lateral meniscus is a feature that can be seen as a normal variant on MRI knee scans. Fat suppressed sagittal T1-weighted MR arthrogram (5C) demonstrates gadolinium within the tear (arrow). The example above illustrates marked degenerative changes caused by loss of meniscal function. Tears in the red zone have the potential to heal and are more amenable to repair. ADVERTISEMENT: Radiopaedia is free thanks to our supporters and advertisers. CT arthrography is recommended for patients with MRI contraindications or when extensive susceptibility artifact from hardware obscures the meniscus. menisci occurs. morphology but lacks its posterior attachments; ie, the meniscotibial Note the symmetrical shape of the lateral meniscus (left) with similar size of the anterior and posterior horns. horn of the lateral meniscus, and oblique tear orientation In the present study, the patients analyzed came from the have been the most difficult for imaging planes to visualize same geographical area . Of these 45 patients, there was an average of 3.74 additional pathological conditions noted on the MRI scan, mainly including degenerative arthrosis or patellar chondromalacia to explain the patients continued pain. A tear of the anterior horn of the lateral meniscus is damage to the front part of one of the two structures that act as shock absorbers between the thigh bone and the lower leg, explains The Steadman Clinic. 5 In the first instance, tears of the lateral aspect of the anterior horn of the medial meniscus are extremely uncommon and should not be a diagnostic History of medial meniscus posterior horn and body partial meniscectomy. (middle third), or Type 3 (superior third; intercondylar notch) (Figure Of the anterior horn tears read on MRI, 85% involved the lateral meniscus anterior horn and about one half were judged to extend into the middle or body of the same meniscus. mobility, and a giving-way sensation.11, 15, 16 A high percentage of cases present with an associated meniscal tear and peripheral rim instability.9,16,17 Although discoid lateral meniscus is commonly bilateral, symptoms tend to occur on one side.15 It is characterized by an excess of meniscal tissue with a slab-like configuration in the 2 most common forms (Figure 5). Sagittal proton density-weighted (14A) and coronal T1-weighted (14B) images reveal a recurrent bucket-handle tear through the original repair site with typical findings of a displaced meniscal flap (arrow) into the intercondylar notch. is in fact reducing the volume of the meniscus and restoring a normal tear. Tears of the anterior horn of the medial meniscus, an inferior patella plica, and ACL tears can be mistaken for AIMM, but carefully tracing the ligament will help to exclude these conditions. 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. proximal medial tibia was convex and the distal medial femoral condyle Lateral meniscus tears of the posterior root are a common concomitant injury to anterior cruciate ligament (ACL) tears [6, 16, 20]. Financial Disclosure: None of the authors or planners for this educational activity have relevant financial relationships to disclose with ineligible companies whose primary business is producing, marketing, selling, reselling, or distributing healthcare products used by or on patients. Clin Orthop Relat Res 2013; 471: pp. With age, increased connective tissue stiffness of the meniscus develops secondary to elastin degradation and collagen rigidification.2. The camera can visualize the meniscus and other structures within the knee. Anomalous Horizontal (degenerative) tears run relatively parallel the tibial plateau. On the sagittal fat-suppressed T2-weighted image (7B), fluid extends into the tear. The most commonly practiced As such, I can count on my hands the number of isolated anterior horn meniscal tears that I have seen at surgery that I felt were symptomatic over the past 5 years. Meniscal root tears are a form of radial tear that involves the central attachment of the meniscus (12a). In these cases, MR arthrography may provide additional diagnostic utility. Discoid lateral meniscus in children. At the time the article was created Yuranga Weerakkody had no recorded disclosures. History of medial meniscus posterior horn partial meniscectomy. Meniscal root tearsare a type of meniscal tearin the knee where the tear extends to either the anterior or posterior meniscal root attachment to the central tibial plateau. In this section, the major patterns of tears are described and depicted in MRIs and arthroscopy images. joint, and they also protect the hyaline cartilage. the medial meniscus. Radiographs may Ideal for residents, practicing radiologists, and fellows alike, this updated reference offers easy-to-understand guidance on how to approach musculoskeletal MRI and recognize abnormalities. There is no telling how much this error rate will change for radiologists less experienced with MRI. Most lateral meniscal tears are due to twisting or turning activities or falls. The reported prevalence is 0.06% to 0.3%.25 This arises from the posterior horn of the lateral meniscus and attaches to the lateral aspect of the medial femoral condyle. Type 2: An incomplete slab of meniscal tissue with 80% coverage of the lateral tibial plateau. Bilateral discoid medial menisci: Case report. Discoid medial meniscus. In children, sometimes an increased signal is seen within meniscus due to increased vascularity, but usually the signal does not contact articular surface. Comparison of Postoperative Antibiotic Regimens for Complex Appendicitis: Is Two Days as Good as Five Days? (PubMed: 17114506), BakerJC, FriedmanMV, RubinDA (2018) Imaging the postoperative knee meniscus: an evidence-based review. The MRI revealed a longitudinal tear in the posterior horn of the lateral meniscus. Tear between 1-4 cm vertical tear red-red meniscal root <40 yo Maybe concominant ACL surgery . The anterior and posterior meniscofemoral ligaments (Humphrey and Wrisberg respectively) are commonly present with one or both found in 93-100% of patients.9 The lateral meniscus is more loosely attached than the medial and can translate approximately 11mm with normal knee motion.10. Click to share on Twitter (Opens in new window), Click to share on Facebook (Opens in new window), Click to share on Google+ (Opens in new window), Posterior Instability and Labral Pathology, Imaging Evaluation of the Painful or Failed Shoulder Arthroplasty, Other Entities: PLRI, HO, Triceps, and Plica, MRI-Arthroscopy Correlations in the Overhead Athlete, Acetabular Fossa, Femoral Fovea, and the Ligamentum Teres. Type 1: A complete slab of meniscal tissue with complete tibial coverage. Best assessed on T2 weighted sequences. The torn edges are aligned, and stable fixation applied with sutures or bioabsorbable implants at approximately 5 mm intervals. We will review the common meniscal variants, which AJR Am J Roentgenol 211(3):519527, De Smet AA. How I Diagnose Meniscal Tears on Knee MRI. Grade II hyperintense horizontal signal of posterior horn of medial meniscus is noted. Anterior horn of the lateral meniscus: another potential pitfall in MR imaging of the knee. Illustration of the medial and lateral menisci. The most widely used diagnostic modalities to assess the ligament injuries are arthroscopy and Magnetic Resonance Imaging (MRI). The condition is typically asymptomatic and, therefore, is infrequently diagnosed.14 Am J Sports Med 2017; 45:4249, ElAttar M, Dhollander A, Verdonk R, Almqvist KF, Verdonk P. Twenty six years of meniscal allograft transplantation: is it still experimental? Dickhaut SC, DeLee JC. The remaining 42 cases were located in the red zone (19 cases) or the red-white zone. 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. On imaging alone, the radiologist may not be able to distinguish a residual tear (failed repair) from a recurrent tear in the same location. MR criteria for discoid lateral menisci are used for discoid medial Atypically thick and high location problem in practice. The anterior root of the lateral meniscus attaches to the tibia, just lateral to the midline and posterior to fibers of the anterior cruciate ligament (ACL). immediatly lateral to the anterior horn of lateral meniscus and posterior to the tubercle of anteriro horn of medial meniscus . In this case, the patient never obtained relief from the initial surgery, and the surgeon felt this was a residual tear (failed repair) rather than a recurrent tear. anterior horn of the medial meniscus into the anterior cruciate ligament It splits into two bands at the PCL, named Humphry(anterior to the PCL) and Wrisberg (posterior to the PCL). Am J Sports Med 2010; 38:15421548, LaPrade RF, Matheny LM, Moulton SG, James EW, Dean CS. Lee S, Jee W, Kim J. Discoid lateral meniscus and the frequency of meniscal tears. pretzels dipped in sour cream. 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). Kocher MS, Klingele K, Rassman SO. Normal This high rate of success, however, may not apply to anterior horn tears, which occur much less commonly than posterior horn and meniscal body tears. Surgery is useful if they are unstable and flipping in and out of the joint causing pain. Lateral Meniscus: Anatomy The lateral meniscus is seen as a symmetric bow tie in the sagittal plane on at least one or two sections before it divides into two asymmetric triangles near the midline. They often tend to be radial tears extending into the meniscal root. Generally, The most common location is the anterior horn-body junction of the lateral meniscus and less commonly in the mid posterior horn or root of the medial meniscus. no specific MR criteria for classifying discoid medial menisci, and the Increased intrameniscal signal is commonly seen in the transplanted allograft but does not correlate with clinical outcome. AJR American journal of roentgenology. Each meniscus attaches to the tibia bone in the back and front via the "meniscal roots." The primary role of the meniscus is to serve as a shock-absorber and protect the underlying articular cartilage and bone. include hypoplastic menisci, absent menisci, anomalous insertion of the Discoid lateral meniscus: Prevalence of peripheral rim instability. The MRI showed complete ACL tear with displaced bucket handle medial meniscus tear. Pre-operative fat supressed coronal proton density-weighted image (19A) demonstates a posterior root radial tear (arrow). It has been calculated that the lateral meniscus absorbs about 70% of the forces across the lateral compartment of the knee. of the menisci can be summarized as providing: Clark and Ogden studied the natural development of the menisci in the ligaments are absent, most commonly the anterior cruciate ligament (ACL) The superior, middle and inferior geniculate arteries are the main vascular supply to the menisci. Most horizontal tears extend to the inferior articular surface. At the time the article was last revised Yahya Baba had However, clinically significant tears that can mechanically impinge were unlikely to have been missed. Repair devices including arrows, darts and sutures are used to approximate the torn edges of the meniscus. 2. Kim EY, Choi SH, Ahn JH, Kwon JW. MR imaging is useful for evaluation of many possible complications following meniscal surgery. 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. 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. The patient had a recent new injury with increased pain. 800-688-2421. | Semantic Scholar Significant increase in signal intensity at the anterior horn of the lateral meniscus near its central attachment site on sagittal magnetic resonance (MR) images of the knee is a normal finding. What are the findings? The knee is a complex synovial joint that can be affected by a range of pathologies: ADVERTISEMENT: Supporters see fewer/no ads, Please Note: You can also scroll through stacks with your mouse wheel or the keyboard arrow keys. Indirect MR arthrography is less commonly used and relies on excretion of intravascular gadolinium into the joint through synovial cells after intravenous administration of gadolinium contrast 20-90 minutes prior to the MRI exam.