anterior horn lateral meniscus tear: mri anterior horn lateral meniscus tear: mri

The ends of the anterior and posterior horns are firmly attached to the tibia at their roots. Radial Meniscal Tear: Pearls May be degenerative or traumatic, vertical, millimeters in size, on the inner edge of the lateral meniscus more commonly than the medial meniscus Meniscal root tears are defined as radial tears located within 1 cm from the meniscal attachment or a bony rootavulsion. Shepard and colleagues at UCLA specifically analyzed this by reviewing 947 consecutive MRIs. Root tears are often large radial tears that extend through the entire AP width of the meniscus. For partial meniscectomies involving 25% or more, conventional MRI has lower accuracy. Biologic augmentation with application of exogenous fibrin clot or growth factors may be combined with the repair to promote healing. Sometimes T2 signal in a healed tear may look similar to fluid. Magnetic resonance imaging of the postoperative meniscus: resection, repair, and replacement. 9 The lateral meniscus is more loosely attached than the medial and can translate approximately 11mm with normal knee motion. American Board of Orthopaedic Surgery Practice of the Orthopaedic Surgeon: Part-II, certification examination case mix. Knee Surg Sports Traumatol Arthrosc. Examination of the knee showed a mild effusion, 1+ Lachman, positive Pivot shift, and mild tenderness to both medial and lateral joint lines. diagnostic dilemma, as the AIMM band will be seen to extend to the As DLM is a congenital anomaly, the ultrastructural features and morphology differ from those of the normal meniscus, potentially leading to meniscal tears. Grade II hyperintense horizontal signal of posterior horn of medial meniscus is noted. Kelly BT, Green DW. A Wrisberg type variant has not been documented in We hope you found our articles The posterior horn is always larger than the anterior horn. 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). AJR Am J Roentgenol. collapse and widening of the medial joint space (Figure 7). Samoto N, Kozuma M, Tokuhisa T, Kobayashi K. Diagnosis of discoid lateral meniscus of the knee on MR imaging. Meniscal root tear. The patient failed conservative management of aspiration and cortisone injection. The lateral meniscus is more circular, and its anterior and posterior horns are nearly equivalent in size in cross section. Associated anomalies in a discoid medial Discoid meniscus in children: Magnetic resonance imaging characteristics. Atypically thick and high location Wrisberg variant, the morphology of the meniscus may be normal, but the 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. 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). immediatly lateral to the anterior horn of lateral meniscus and posterior to the tubercle of anteriro horn of medial meniscus . Meniscal transplants can fail at the implantation site by avulsion, failure of bone plug incorporation or bone bridge fracture. Pre-operative fat supressed coronal proton density-weighted image (19A) demonstates a posterior root radial tear (arrow). As a result, the accuracy rate of diagnosis by MRI is 83.3%. During an arthroscopy, we have the choice of either repairing the meniscus tear or removing the torn piece. Discoid medial meniscus. Pathology - a tear that has developed gradually in the meniscus. Check for errors and try again. Anterior horn of the lateral meniscus: another potential pitfall in MR imaging of the knee. Pinar H, Akseki D, Karaoglan O, et al. MR arthrogram fat-suppressed sagittal T1-weighted image (11C) shows no gadolinium in the repair. No meniscal tear is seen, but the root attachment was also noted to be Their conclusion that one should not perform surgery unless clinical correlation exists with effusions, mechanical catching or locking, or the failure to respond to nonoperative measures I believe is a good recommendation that we can all follow. The most frequent symptom is pain that usually begins with a minor 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? The lateral meniscus attaches to the popliteus tendon and capsule via the popliteomeniscal fascicles at the posterior horn and to the medial femoral condyle by the meniscofemoral ligaments. Grades 1 and 2 are not considered serious. 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 . Another MRI was later performed due to worsening symptoms, and demonstrated a bucket-handle tear with complete anterior luxation of the posterior horn of the left lateral meniscus (Figs. 6. Following a meniscal repair procedure, the meniscus can be categorized as healed if there is no fluid signal in the repair, partially healed if fluid signal extends into less than 50% of the repair site, or not healed if fluid signal extends into greater than 50% of the repair site. Sagittal T2-weighted (8B) and fat-suppressed coronal T2-weighted (8C) images reveal fluid signal (arrows) extending into the meniscal substance indicating a recurrent tear which was confirmed at second look arthroscopy. Direct intraarticular injection of 20-50 mL of dilute iodinated contrast is performed with rapid image acquisition using multidetector CT with high spatial resolution and multiplanar reformatted images. Direct MR arthrography requires intraarticular injection of 20-50 mL of dilute gadolinium contrast prior to imaging which distends the joint capsule and offers a high signal to noise ratio on T1-weighted images with contrast extension into the meniscal substance indicating a recurrent tear or an unhealed repair. Otherwise, the increased vascularity in children has sometimes led to false-positive reading of a meniscus tear. Pullout fixation of posterior medial meniscus root tears: correlation between meniscus extrusion and midterm clinical results. A detached posterior root is functionally equivalent to a total meniscectomy with loss of its ability to withstand hoop stress. Intensity of signal contacting meniscal surface in recurrent tears on MR arthrography compared with that of contrast material. congenital absence of the cruciate ligaments. Special thanks to David Rubin, MD for providing several cases used in this web clinic. 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. In cases like this, MR arthrography is quite helpful. RESULTS. The lateral . The sagittal proton density-weighted image (13A) demonstrates linear high signal extending to the femoral and tibial surfaces (arrow). 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. Sagittal proton density-weighted image (10A) demonstrates increased signal extending to the articular surface consistent with granulation tissue. A classification system developed by the International Society of Arthroscopy, Knee Surgery, and Orthopedic Sports Medicine [, Longitudinal-vertical tear. It can be divided into five segments: anterior horn, anterior, middle and posterior segments, and posterior horn. 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. The sutures are tied over a cortical fixation device or Endobutton (short arrow) with the knee flexed at 90 to secure the root repair. the menisci of the knees. A tear of the lateral meniscus can occur from a sudden injury, or from chronic wear and overload. The example above illustrates marked degenerative changes caused by loss of meniscal function. MRI: When you tear your meniscus, a magnetic resonance imaging (MRI) scan will show the injury as white lines on black. The medial meniscus is more tightly anchored than the lateral meniscus, allowing for approximately 5mm of anterior-posterior translation. 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. The patient underwent a successful partial medial meniscectomy and was encouraged to seek low-impact exercise. described in thrombocytopenia absent radius syndrome (TAR syndrome).2,3 Bilateral hypoplasia of the medial meniscus has also been reported.4. The incidence was calculated based on arthroscopic findings, and the potential secondary signs of meniscal ramp tears were evaluated on MRI. in 19916. MR criteria for discoid lateral menisci are used for discoid medial Brody J, Lin H, Hulstyn M, Tung G. Lateral Meniscus Root Tear and Meniscus Extrusion with Anterior Cruciate Ligament Tear. 17. Best assessed on T2 weighted sequences. Variations in meniscofemoral ligaments at anatomical study and MR imaging. Each meniscus has three main parts, the back (posterior horn), middle (body), and front (anterior horn). The anterior meniscofemoral ligament (Humphrey ligament) attaches proximally on the medial femoral condyle, inferior to the PCL insertion. Kaplan EB. 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. 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. Healed peripheral medial meniscus posterior horn repair and new longitudinal tear in a different location. 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. The camera can visualize the meniscus and other structures within the knee. for the ratio of the sum of the width of the anterior and posterior 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 [. This scan showed a radial MMT. 3: The Wrisberg variant, where the meniscus may have a normal However, this conjecture and others pre- highest.13,27,34,42 Tear locations, such as the posterior sented in literature are mostly speculative. Meniscal tears are common and often associated with knee pain. ligament, and the posterior horn may translate or rotate due to However, few studies have directly compared the medial and lateral root tears. 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. The meniscal repair is intact. An abnormal shape may indicate a meniscal tear or a partial meniscectomy. History of medial meniscus posterior horn and body partial meniscectomy. of the transverse ligament is comparable to the general population.5. 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 . medial meniscus, and not be confined to the ACL as seen in an ACL tear. Fukuta S, Masaki K, Korai F. Prevalence of abnormal findings in magnetic resonance images of asymptomatic knees. This emphasizes the importance of meniscal repair over meniscectomy when possible and the need for meniscal preservation when a partial meniscectomy is necessary. Kijowski et al. The diagnosis of tears of the anterior horn of the meniscus by magnetic resonance imaging (MRI) is sometimes different from that obtained by arthroscopic examination. Become a Gold Supporter and see no third-party ads. Congenital discoid cartilage. 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. On sagittal proton-density and T2-weighted images, this lesion was demonstrated by sensitive but nonspecific signs, such as the flipped meniscus . congenital anomalies affect the lateral meniscus, most commonly a Source: Shepard MF, et al. 2006; 187:W565568. menisci develop from this mesenchymal tissue in a site where this tissue trials, alternative billing arrangements or group and site discounts please call At second look arthroscopy, the posterior horn tear was healed and the anterior horn tear was found to be unstable and treated by partial meniscectomy. menisci (Figure 8). Copy. Sagittal T2-weighted image (10B) reveals no fluid at the repair site. Nakajima T, Nabeshima Y, Fujii H, et al. Lateral meniscus extrusion was present in six (23%) of 26 LMRTs and five (2.2%) of 231 patients with normal meniscus roots ( P < .001). instance, tears of the lateral aspect of the anterior horn of the Relevant clinical history, prior imaging and use of operative reports will significantly improve accuracy of post-operative interpretations. horns to the meniscal diameter on a sagittal slice that shows a maximum CT arthrography may be used to evaluate the postoperative meniscus when MRI is contraindicated. Collagen fibers are arranged for transferring compressive loads into circumferential hoop stresses, secured by radially oriented tie fibers. 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. 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 anterior horn of the medial meniscus into the anterior cruciate ligament Studies on meniscus root tears have investigated the relationship of osteoarthritis and an anterior cruciate ligament tear. problem in practice. menisci occurs. joint: Morphologic changes and their potential role in childhood The patient underwent an all-inside lateral meniscus repair. 6 months post-operative she had increased pain prompting follow-up MRI. Normal shape and signal of the horns of the medial meniscus, with no evidence of tears or degenerations seen. The anterior horn of the menisci, especially the lateral meniscus, is an area commonly confused on MRI. What is a Grade 3 meniscus tear? 2008;191(1):81-5. Tachibana Y, Yamazaki Y, Ninomiya S. Discoid medial meniscus. Arthroscopy revealed a horizontal tear of PHMM, and a partial medial meniscectomy was performed. Dr. Michael Gabor answered Diagnostic Radiology 35 years experience No,: It doesn't sound like a bucket handle tear By continuing to use our site, you consent to the use of cookies outlined in our Privacy Policy. Imaging characteristics of the It is often explained by fibers of the anterior cruciate ligament and the covering synovium . We use cookies to create a better experience. Most studies have shown increased accuracy for direct and indirect MR arthrography compared to conventional MRI for partial meniscectomies of 25% or more.16. insertion of the medial meniscus (AIMM) has been described, and it is 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. 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. Considered a feature of knee osteoarthritis. ADVERTISEMENT: Radiopaedia is free thanks to our supporters and advertisers. Radiographs are usually not diagnostic, but they may show a 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. the rare ring-shaped meniscus, to the classification. A meniscus is a crescent-shaped fibrocartilaginous structure that Both horns of the medial meniscus are triangular with sharp points. 4). The discoid lateral-meniscus syndrome. Suprapatellar plica noticed, with no related cartilaginous erosions. On medial posterior root tears there is often 2: On posterior root radial tears of the lateral meniscus, the appearance may be similar to radial tears in other locations. Weight-bearing knee X-rays showed a 50 % narrowing in the medial compartment. There was no history of a specific knee injury. 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. A previous study by De Smet et al. Check for errors and try again. diminutive (1 mm) with no increased signal to suggest root attachment meniscal injury. No paralabral cyst. Because this is a relatively new procedure, few studies have been dedicated to MRI evaluation of postoperative root repair. Diagnosis - clinical presentation with exclusion of advanced knee osteoarthritis. Normal course and intensity of both cruciate ligaments. The self-reported complication rate for partial meniscectomy is 2.8% and meniscus repair is 7.6%. 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. 1427-143. Report Kim EY, Choi SH, Ahn JH, Kwon JW. Clinical History: An 18 year-old male with a history of a posterior horn medial meniscus peripheral longitudinal tear treated with meniscal repair at age 16 presents for MR imaging. Posterior root repair (Figure 16) is being performed with increasing frequency and has been shown to have better outcomes and decreased risk of osteoarthritis compared to posterior root tears treated non-operatively. They may not even be apparent with an arthroscopic examination. Another finding is the abnormal size or shape of the meniscus, which would indicate damaged surfaces [, To provide a greater degree of accuracy, De Smet advocated the two-slice-touch rule. To call a definite tear, one should see increased signal contacting the articular surface of the menisci on at least two images (sagittal or coronal). Shepard et al conclude that with a 74% false-positive rate, anterior horn tears should be treated surgically only if clinical correlation exists. This injury is biomechanically comparable to a total meniscectomy, leading to compromised hoop stressesresulting in decreased tibiofemoral contact area and increased contact pressures in the involved compartment.These changes are detrimental to the articular cartilage and . A tear of the ACL should also, in practice, not be a Advantages include a less invasive method of introducing intraarticular contrast, the ability to identify areas of hyperemic synovitis or periarticular inflammation based on enhancement and administration can be performed by the technologist. morphology but lacks its posterior attachments; ie, the meniscotibial Lateral meniscus tears of the posterior root are a common concomitant injury to anterior cruciate ligament (ACL) tears [6, 16, 20]. Radiology. Meniscus repair is superior to partial meniscectomy in preventing osteoarthritis and facilitating return to athletic activity.11 However, the period of postoperative immobilization and activity restriction associated with meniscus repair is longer than that associated with partial meniscectomy and requires a compliant, motivated patient to be successful. Cho JM, Suh JS, Na JB, et al. 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. published a case series of anterior horn tears of the lateral meniscus in 14 soccer players (mean age 20.2 years). The main functions are reported cases of complete absence of the medial meniscus as 2006; 88:660667, Boutin RD, Fritz RC, Marder RA. appearance.12 It is now believed that the knee develops from a