A meniscal allograft transplant frequently leads to significant improvements in pain and activity level and hastens the return to sport for most amateur and professional athletes.13 A common method of meniscal allograft transplant includes a cadaveric meniscus (fresh or frozen) attached by its anterior and posterior roots to a bone bridge with a trapezoidal shape harvested from a donor tibia. The symptoms Controlling Blood Pressure During Pregnancy Could Lower Dementia Risk, Researchers Address HIV Treatment Gap Among Underserved Population, HHS Announces Reorganization of Office for Civil Rights, FDA Adopts Flu-Like Plan for an Annual COVID Vaccine. The lateral . Again, this emphasizes the importance of accurate history, prior imaging and operative reports. Grades 1 and 2 are not considered serious. Associated anomalies in a discoid medial 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 patient underwent partial medial meniscectomy and ACL reconstruction. Bilateral discoid medial menisci: Case report. An athletic 52-year-old male, who was an avid runner all his adult life, presented with medial pain and a popping sensation in knee. Anterior horn of the lateral meniscus: another potential - PubMed both enjoyable and insightful. For partial meniscectomies involving 25% or more, conventional MRI has lower accuracy. A previous study by De Smet et al. 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. The examiner can test the entire posterior horn up to the middle segment of the meniscus using the IR of the tibia followed by an extension. The location of meniscal tears or signal alterations (anterior/posterior horn or body of the medial/lateral meniscus) and the grade (normal/intra-substance signal abnormality = 0 and tear = 1) were determined on 2D . They divide the meniscus into superior and inferior halves (Fig. Am J Sports Med 2016; 44:625632, De Smet AA, Horak DM, Davis KW, Choi JJ. Normal menisci. Shepard et al conclude that with a 74% false-positive rate, anterior horn tears should be treated surgically only if clinical correlation exists. 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. 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. However, the tear changes plane of orientation over its course. Definite surfacing signal or distortion on only one image represents a possible tear. MR criteria for discoid lateral menisci are used for discoid medial Normal course and intensity of both cruciate ligaments. Anterior Cruciate Ligament and Meniscal Tears: A Multi-modality Review A characteristic MRI finding to diagnose a partial tear of the medial Meniscus Tears: Understand your MRI results | Scott Hacker MD tear. 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 . Because there is less pressure on the meniscus there, it is difficult to evaluate the anterior region of the meniscus. This scan showed a radial MMT. There are 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. ligaments and menisci causing severe knee dysplasia in TAR syndrome. However, this conjecture and others pre- highest.13,27,34,42 Tear locations, such as the posterior sented in literature are mostly speculative. Volunteerism and Sports Medicine: Where do We Stand? in 19916. Tear between 1-4 cm vertical tear red-red meniscal root <40 yo Maybe concominant ACL surgery . morphology but lacks its posterior attachments; ie, the meniscotibial Acute partial interstitial to near complete anterior cruciate ligament tear is noted at its posterior end with femoral deep lateral sulcus sign. meniscal diameter. 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. This case features the following signs of meniscal tear: Case courtesy, Prof. Dr. Khaled Matrawy, Professor of radiology, Alexandria university, Egypt. Am J Sports Med. The anterior root of the medial meniscus attaches to the anterior midline of the tibial plateau or sometimes the anterior surface of the tibia just below the plateau. posterior fascicles and meniscotibial ligament are absent and a high They often tend to be radial tears extending into the meniscal root. Discoid meniscus in children: Magnetic resonance imaging characteristics. joint: Morphologic changes and their potential role in childhood What is your diagnosis? The anterior and posterior sutures are shuttled down the tibial tunnel (arrowhead). was saddle shaped. The meniscus is diffusely vascularized in early life but in adults, only 10-30% of the peripheral meniscus is vascularized, often referred to as the red zone. When it involves the posterior root, medial root tears are easier to diagnose than lateral root tears. are reported cases of complete absence of the medial meniscus as 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 . In this section, the major patterns of tears are described and depicted in MRIs and arthroscopy images. the posterior horn is usually much larger than the anterior horn (the A tear of the meniscal root means the tear is near where it attaches to the bone, usually far in the back. AJR Am J Roentgenol 2009;193:515-523. Medial meniscus posterior horn peripheral longitudinal tear treated with repair. ligament and meniscal fascicles. FSE T2-weighted images, with a slab-like appearance on coronal images. Diagnosis of recurrent meniscal tears: prospective evaluation of conventional MR imaging, indirect MR arthrography, and direct MR arthrography. The medial compartment articular cartilage is preserved, and the meniscal body is not significantly extruded (16D). 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 [. 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. Repair techniques include side-to-side repair, stabilization with suture anchors, and the transtibial pull-out technique (figure 4).12. Radiology. This article focuses on Create a new print or digital subscription to Applied Radiology. 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. 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. appearance.12 It is now believed that the knee develops from a Pinar H, Akseki D, Karaoglan O, et al. Kijowski et al. You can use Radiopaedia cases in a variety of ways to help you learn and teach. They may not even be apparent with an arthroscopic examination. As visualized on sagittal MR images, the anterior horn of the medial meniscus is shorter than the posterior horn, whereas the anterior and posterior horns of the lateral meniscus are of equal length. While they can arise from a number of mechanisms, root tears are generally thought to be chronic 5. Congenital discoid cartilage. ADVERTISEMENT: Radiopaedia is free thanks to our supporters and advertisers. Pathology - a tear that has developed gradually in the meniscus. After preparing the recipient knee by creating a matching keyhole trough in the tibia, the surgeon slides the allograft bone plug into its matching tibial slot and sutures the periphery of the allograft meniscus to the capsule. Conventional MRI is the least invasive modality for evaluation of a meniscal repair but has lower sensitivity, specificity and accuracy than direct or indirect arthrographic MRI. Thirty-one of these patients underwent subsequent arthroscopic evaluation to allow clinical correlation. Check for errors and try again. Bilateral Hypoplasia of the Medial and Lateral Menisci - PMC It affects 4% to 5% of the patient population,6-9 with a much higher incidence, up to 13%, in the Asian patient population.10 It is the most common meniscal variant in children.11 Variations in meniscofemoral ligaments at anatomical study and MR imaging. Comparison of Medial and Lateral Meniscus Root Tears - PLOS Discoid medial meniscus. An algorithm for computing tear meniscus profile The articular cartilage is well seen on the pre-operative sagittal proton density-weighted image (19B). The torn edges are aligned, and stable fixation applied with sutures or bioabsorbable implants at approximately 5 mm intervals. A tear of the lateral meniscus can occur from a sudden injury, or from chronic wear and overload. Objectives: Low-field MRI at 0.55 Tesla (T) with deep learning image reconstruction has recently become commercially available. History of medial meniscus posterior horn and body partial meniscectomy. American Board of Orthopaedic Surgery Practice of the Orthopaedic Surgeon: Part-II, certification examination case mix. Thus, the loss of the lateral meniscus can often lead to rather rapid onset of osteoarthritis. horns to the meniscal diameter on a sagittal slice that shows a maximum This emphasizes the importance of meniscal repair over meniscectomy when possible and the need for meniscal preservation when a partial meniscectomy is necessary. to the base of the ACL or the intercondylar notch. When the cruciate The MRI also demonstrated moderate degenerative spurring at the lateral joint compartment, a large knee joint effusion with . De Smet A. The meniscal repair is intact. ligament, and the posterior horn may translate or rotate due to Their 74% false-positive rate I believe is accurate and one that we can incorporate mentally into our practice as we evaluate patients and the MRI scan results. What causes abnormal mobility in the medial meniscus? Discoid medial menisci are much less common than discoid lateral menisci,24 and they may be bilateral. Incidence and Detection of Meniscal Ramp Lesions on Magnetic Resonance diagnostic dilemma, as the AIMM band will be seen to extend to the The meniscus can separate from the joint capsule or tear through the allograft. On this page: Article: Epidemiology Pathology Radiographic features History and etymology Fukuta S, Masaki K, Korai F. Prevalence of abnormal findings in magnetic resonance images of asymptomatic knees. With age, increased connective tissue stiffness of the meniscus develops secondary to elastin degradation and collagen rigidification.2. The anterior horn inserts on the tibia and continues laterally to the anterior horn of the lateral meniscus via the transverse intermeniscal ligament. Association of Parameniscal Cysts With Underlying Meniscal Tears as In some patients, hyperintense signal may persist at the repair site on conventional MRI for several years and is thought to represent granulation tissue. 2020;49(1):42-49. Grade 3 is a true meniscus tear and an arthroscope is close to 100 percent accurate in diagnosing this tear. meniscus. 3 is least common. Stein T, Mehling AP, Welsch F, von EisenhartRothe R, Jger A. The purpose of our study was to determine if cysts of the ACL are the origin of cysts adjacent to the AHLM. The main functions There are 3 main types, according to the Watanabe classification:18. is affected. Analytical, Diagnostic and Therapeutic Techniques and Equipment 13. The anterior horn of the menisci, especially the lateral meniscus, is an area commonly confused on MRI. Schwenke M, Singh M, Chow B Anterior Cruciate Ligament and Meniscal Tears: A Multi-modality Review. during movement, and less commonly joint-line tenderness, reduced Bucket-handle tear of the lateral meniscus: Flipped meniscus sign this may extend to to the mid body." is this a bucket tear? Comparison of Postoperative Antibiotic Regimens for Complex Appendicitis: Is Two Days as Good as Five Days? The congenitally absent meniscus appears to influence the development Continuous meniscal tissue bridged the anterior and posterior horns of the lateral meniscus on 3 consecutive sagittal slices (Figure 1B). The camera can visualize the meniscus and other structures within the knee. The MRI showed complete ACL tear with displaced bucket handle medial meniscus tear. The most common The patient had a recent new injury with increased pain. Anomalous Interested in Group Sales? MRI Findings: Medial meniscus: Tear of the posterior horn seen to the inferior articular surface continuing into the posterior body and becoming more vertical. of the anterior horn of the medial meniscus, an inferior patella plica, It is believed that discoid How I Diagnose Meniscal Tears on Knee MRI : American Journal of Conventional MRI imaging correlates well with arthroscopic evaluation of the transplants for tears of the posterior and middle thirds of the meniscus allograft with a high sensitivity, specificity and accuracy, but results were poor for evaluation of the anterior third with a low specificity and accuracy.16 Allograft shrinkage and meniscus extrusion are common findings on postoperative MRI but do not always correlate with patient pain and function. meniscus | Search | Radiopaedia.org 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. The LaPrade classification systemof meniscal root tears has become commonly used in arthroscopy, and there is evidence that this system can be to some extent translated to MRI assessment of these tears ref. They found that 76 (8%) of these indicated a tear of the anterior horn of either the medial or lateral meniscus. rim circumferentially, anteriorly, and posteriorly,19 which slab-like configuration on sagittal MR images, with > 3 bowties 2006; 88:660667, Boutin RD, Fritz RC, Marder RA. Dr. Diduch, Associate Professor, Department of Orthopaedic Surgery, University of Virginia School of Medicine, Charlottesville, VA, is Editor of Sports Medicine Reports. Discoid lateral meniscus APPLIED RADIOLOGY 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). Suprapatellar plica noticed, with no related cartilaginous erosions. The shape of the meniscus is formed at the eighth week of Extrusion is commonly seen following root repair. noted to be diminutive, with the posterior horn measuring 7 mm to 8 mm. Both the healed peripheral tear and the new central tear were proved at second look arthroscopy. In these cases, surfacing meniscal signal on low TE series may represent recurrent tear, granulation tissue or residual grade 2 degenerative signal that contacts the meniscal surface after debridement. Coronal extrusion of the lateral meniscus does not increase after anterior horn of the medial meniscus into the anterior cruciate ligament If the tear does not show, it is considered a Grade 1 or 2 and is not as serious. Sagittal proton density-weighted image (8A) through the medial meniscus demonstrates signal extending to the tibial surface (arrow). The Journal of bone and joint surgery American volume. MRI: When you tear your meniscus, a magnetic resonance imaging (MRI) scan will show the injury as white lines on black. Special thanks to David Rubin, MD for providing several cases used in this web clinic. Unable to process the form. the medial meniscus. These include looking for a and ACL tears can be mistaken for AIMM, but carefully tracing the discoid lateral meniscus is a relatively uncommon developmental variant frequently. In cases like this, MR arthrography is quite helpful. of the meniscus. There is no telling how much this error rate will change for radiologists less experienced with MRI. The patient underwent an all-inside lateral meniscus repair. Arthroscopy is considered gold standard in the diagnosis of knee ligament injuries, with diagnostic accuracy up to 94% [1], [2]; and can be used therapeutically as well. 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. the intercondylar notch, most commonly to the mid ACL, and less commonly Radiographs may The posterior root of the lateral meniscus (PRLM) attaches along the posterior aspect of the intercondylar eminence of the tibia (Fig. After failing conservative management with NSAIDs, PT, and activity modification, he underwent an MRI. meniscal injury. joint, and they also protect the hyaline cartilage. Of these patients treated nonoperatively, 6 had a diagnosis of an isolated anterior horn tear on MRI. Menisci ensure normal function of the The sutures are tied over a cortical fixation device or Endobutton (short arrow) with the knee flexed at 90 to secure the root repair. 5. Medial meniscus bucket handle tears can result in a double PCL sign. show cupping of the medial tibial plateau, proximal medial tibial physis Symptomatic anomalous insertion of the medial meniscus. Tears can be characterized by length, depth, shape, gap, displacement, stability, dysplasia (discoid) Arthroscopy evaluation found a lateral meniscus peripheral (red-white zone) longitudinal tear. On examination, there was marked medial joint line tenderness and a large effusion. Magnetic resonance imaging (MRI) of both knee joints showed an almost complete absence of the anterior and posterior horns of the medial meniscus, except for the peripheral portion, hypoplastic anterior horns and tears in the posterior horns of the lateral meniscus in both knees (Fig. There is no universally accepted system for classifying meniscal tear patterns. PRIME PubMed | Posterior horn lateral meniscal tears simulating Discoid lateral meniscus. At least one meniscofemoral ligament is present in 7093 % Of knees An intact meniscal repair was confirmed at second look arthroscopy. medial meniscus are extremely uncommon and should not be a diagnostic Anterior tibial marrow edema and organized trabecular fracture measuring 16 mm AP, 18 mm transverse. No meniscal tear is seen, but the root attachment was also noted to be Stay up to date with the latest in Practical Medical Imaging and Management with Applied Radiology. This emphasizes the importance of baseline MRI comparison for evaluation of the postoperative meniscus.3. 2014; 43:10571064, McCauley TR. The MFL was not observed in five (19%) of 26 studies of an LMRT. 2002; 222:421429, Ciliz D, Ciliz A, Elverici E, Sakman B, Yuksel E, Akbulut O. Br Med Bull. Radial Meniscal Tear - ProScan Education - MRI Online 2. A detached posterior root is functionally equivalent to a total meniscectomy with loss of its ability to withstand hoop stress. Skeletal radiology. Meniscal root tears are a form of radial tear that involves the central attachment of the meniscus (12a). 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). Connolly B, Babyn PS, Wright JG, Thorner PS. Anterior horn tear of the lateral meniscus in footballers with a stable knee is characterized by pain at the anterolateral aspect of the knee during knee extension, especially when kicking. It has been calculated that the lateral meniscus absorbs about 70% of the forces across the lateral compartment of the knee. MRI Gallery - MRI Knee - Meniscal tears - Radiology Masterclass patella or Hoffas fat pad, and should be fairly easily differentiated : Complications in brief: arthroscopic partial meniscectomy. Magnetic resonance imaging (MRI) is the most accurate imaging technique in the diagnosis of meniscal lesions and represents a standard tool in knee evaluation. Meniscus | Radiology Key varus deformity (Figure 3). Disadvantages include increased cost, increased patient time, potential for adverse reactions to contrast agent compared to conventional MRI and lack of joint distention. Proper preoperative sizing of the allograft is critical for surgical success and usually performed with radiographs. Sometimes T2 signal in a healed tear may look similar to fluid. Clinical Examination in the Diagnosis of Anterior Cruciate : JAAOS Similarly, the postoperative meniscus is at increased risk for a recurrent tear either at the same or different location due redistribution of forces and increased stress on the articular surface. Cysts of the anterior horn lateral meniscus and the ACL: is there a 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. Wrisberg variant, the morphology of the meniscus may be normal, but the Presentation - Middle-older aged individuals, non-traumatic, progressive onset of pain. The insertion site MR arthrogram fat-suppressed sagittal T1-weighted image (11C) shows no gadolinium in the repair. (PDF) Sensitivity and Specificity of MRI in Diagnosing Concomitant Learn more. reported.4. 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. The condition is typically asymptomatic and, therefore, is infrequently diagnosed.14 CT arthrography may be used to evaluate the postoperative meniscus when MRI is contraindicated. The discoid lateral-meniscus syndrome. Diagnostic performance is decreased following partial meniscectomy since the standard criteria used to diagnose a meniscus tear cannot be applied to the post-operative meniscus.3,4,5,6 Partial meniscectomy may distort the normal morphology of the meniscus and increased meniscal signal intensity may extend to the articular surface when a portion of the meniscus has been resected, simulating a tear.