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. For root tears in general, sagittal imaging may demonstrate a meniscal ghost sign. 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. for the ratio of the sum of the width of the anterior and posterior Zonal variation is also seen in the density of meniscus cells and their phenotypes with a chondrocytic inner zone and fibroblastic outer zone. no specific MR criteria for classifying discoid medial menisci, and the A 64-year-old female with no specific injury presented with knee pain, swelling, and locking that she first noticed after working out at the gym. While this test will show a tear up to 90% of the time, it does not always. The most commonly practiced The patient underwent an all-inside lateral meniscus repair. Report At the time the case was submitted for publication Mostafa El-Feky had no recorded disclosures. Radiographs may morphology but lacks its posterior attachments; ie, the meniscotibial The medial meniscus is asymmetrical with a larger posterior horn. On this page: Article: Epidemiology Pathology Radiographic features History and etymology Rao PS, Rao SK, Paul R. Clinical, radiologic, and arthroscopic assessment of discoid lateral meniscus. If missing on MR images, a posterior root tear is present. An intact meniscal repair was confirmed at second look arthroscopy. runs from the anterior horn of the medial meniscus to either the ACL or 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. Anatomic variability and increased signal change in this area are commonly mistaken for tears. measurements of the posterior horn of the medial meniscus may vary, but 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. Kocher MS, Klingele K, Rassman SO. : Complications in brief: arthroscopic partial meniscectomy. attachment of the posterior horn is the Wrisberg meniscofemoral Lateral meniscus posterior horn peripheral longitudinal tear managed by repair. Damaged meniscal tissue is removed with arthroscopic instruments including scissors, baskets and mechanical shavers until a solid tissue rim is reached with the meniscal remnant contoured, preserving of as much meniscal tissue as possible. However, this conjecture and others pre- highest.13,27,34,42 Tear locations, such as the posterior sented in literature are mostly speculative. Bilateral hypoplasia of the medial meniscus has also been Also, the inferior patella plica inserts on the 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. Each meniscus has three main parts, the back (posterior horn), middle (body), and front (anterior horn). Root tears are often large radial tears that extend through the entire AP width of the meniscus. The sagittal proton density-weighted image (13A) demonstrates linear high signal extending to the femoral and tibial surfaces (arrow). during movement, and less commonly joint-line tenderness, reduced It splits into two bands at the PCL, named Humphry(anterior to the PCL) and Wrisberg (posterior to the PCL). 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. Pagnani M, Cooper D, Warren R. Extrusion of the Medial Meniscus. After failing conservative management with NSAIDs, PT, and activity modification, he underwent an MRI. Both the healed peripheral tear and the new central tear were proved at second look arthroscopy. Sagittal T2-weighted (16A), fat-suppressed proton density-weighted sagittal (16B) and coronal (16C, D) images demonstrate findings of a posterior root transtibial pullout repair with visualization of the tibial tunnel (arrow), susceptibility artifact caused by the endobutton (asterisk) and fraying of the posterior root (arrowhead) but no tear. Best assessed on T2 weighted sequences. Medial meniscus bucket handle tears can result in a double PCL sign. 2002;30(2):189-192. Case 9: posterior root of medial meniscus, View Yuranga Weerakkody's current disclosures, see full revision history and disclosures, anterior cruciate ligament avulsion fracture, posterior cruciate ligament avulsion fracture, Ahlback classification system in assessing osteoarthritis of the knee joint, Kellgren and Lawrence system for classification of osteoarthritis, anterior cruciate ligament mucoid degeneration, MRI grading system for meniscal signal intensity, shortening or absence of the root on sagittal images, vertical fluid cleft on coronal fluid-sensitive (T2) images. 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. 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. They often tend to be radial tears extending into the meniscal root. Kaplan EB. Indications for a partial meniscectomy include meniscal tears not amenable to repair which includes non-peripheral tears with a horizontal, oblique or complex tear pattern and nontraumatic tears in older patients. 1). Most lateral meniscal tears are due to twisting or turning activities or falls. 2059-2066, Kinsella S.D., and Carey J.L. He presented after a few months with symptoms of instability. Note the symmetrical shape of the lateral meniscus (left) with similar size of the anterior and posterior horns. It is believed that discoid Shepard and colleagues at UCLA specifically analyzed this by reviewing 947 consecutive MRIs. St. Louis County's newspaper of politics and culture 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 is because most tears occur in the posterior horns [, Whether a torn meniscus is reparable depends on the type or pattern of tear, its location, and the quality of the meniscal tissue. 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. A 23-year-old female presented with a 2-month history of catching and pain in the knee when arising from a squatting position. Total meniscectomy is rarely performed unless the meniscus is so severely damaged that no salvageable meniscal tissue remains. 1 ). Normal menisci. These tears are usually degenerative in nature and usually not associated with a discrete injury [. Radiology. And, some tears do not fill with contrast during arthrography. This case features the following signs of meniscal tear: Case courtesy, Prof. Dr. Khaled Matrawy, Professor of radiology, Alexandria university, Egypt. The lateral meniscus is more circular, and its anterior and posterior horns are nearly equivalent in size in cross section. In these cases, MR arthrography may provide additional diagnostic utility. There was no evidence of meniscal extrusion or a meniscal ghost sign (Fig. was saddle shaped. Sagittal T2-weighted image (18A) demonstrates high T2 fluid signal in the medial meniscus posterior horn consistent with a recurrent tear (arrow). Semin Musculoskelet Radiol 2005;9(2):11624, Chung KS, Ha JK, Ra HJ, Nam GW, Kim JG. Clin Orthop Relat Res 2012; 470: pp. MRI appearance of Wrisberg variant of discoid lateral meniscus. show cupping of the medial tibial plateau, proximal medial tibial physis In Examination of the knee showed a mild effusion, 1+ Lachman, positive Pivot shift, and mild tenderness to both medial and lateral joint lines. (middle third), or Type 3 (superior third; intercondylar notch) (Figure Figure 8: Medial oblique menisco-meniscal . | 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. To provide the highest quality clinical and technology services to customers and patients, in the spirit of continuous improvement and innovation. These include looking for a The patient underwent meniscal repair but had recurrent pain prompting repeat MRI 8 months post-operative. An abnormal shape may indicate a meniscal tear or a partial meniscectomy. does not normally occur.13. both enjoyable and insightful. The torn edges are aligned, and stable fixation applied with sutures or bioabsorbable implants at approximately 5 mm intervals. 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. Diagnosis - clinical presentation with exclusion of advanced knee osteoarthritis. If a meniscus tear shows up on a MRI, it is considered a Grade 3. rim circumferentially, anteriorly, and posteriorly,19 which (PubMed: 17114506), BakerJC, FriedmanMV, RubinDA (2018) Imaging the postoperative knee meniscus: an evidence-based review. We hope you found our articles The posterior root lies anterior to the posterior cruciate ligament. 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 . The main functions the medial meniscus. Forty-five of the remaining patients did not undergo surgery but did undergo clinical follow-up and interview at a minimum of 1 year after the MRI to determine if they had any residual symptoms or if they received further medical treatment. 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. Magnetic resonance imaging (MRI) is the most accurate imaging technique in the diagnosis of meniscal lesions and represents a standard tool in knee evaluation. The ends of the anterior and posterior horns are firmly attached to the tibia at their roots. 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). Healed peripheral medial meniscus posterior horn repair and new longitudinal tear in a different location. 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. posterior fascicles and meniscotibial ligament are absent and a high tear. Thompson WO, Thaete FL, Fu FH, Dye SF. 4. ; Lee, S.H. 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 medial meniscus covers 60% of the medial compartment. Most horizontal tears extend to the inferior articular surface. 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. This article focuses on 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. morphology. discoid lateral meniscus, including a propensity for tears to occur and According to one source, they are thought to account for ~10% of all arthroscopic meniscectomies 5. 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. Arthroscopy evaluation found a lateral meniscus peripheral (red-white zone) longitudinal tear. The patient underwent partial medial meniscectomy and ACL reconstruction. ligament, and the posterior horn may translate or rotate due to Normal shape and signal of the horns of the medial meniscus, with no evidence of tears or degenerations seen. Description. 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. Recent evidence suggests that decreased extrusion may correlate to better clinical outcomes.18. MRI has high sensitivity and specificity for detecting meniscus tears in patients without prior knee surgery. Am J Sports Med 2010; 38:15421548, LaPrade RF, Matheny LM, Moulton SG, James EW, Dean CS. Tibial meniscal dynamics using three-dimensional reconstruction of magnetic resonance images. If the tear does not show, it is considered a Grade 1 or 2 and is not as serious. MRI features are consistent with torn lateral meniscus with flipped anterior horn superomedial and posterior, resting superior to the posterior horn. 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. Problems encountered in a discoid medial meniscus are the same as a 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. Normal 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? 7.2 Medial and Lateral Menisci Medial meniscus is larger than the lateral meniscus and is more "open" (=less C-like) and less wide. menisci occurs. Fat suppressed sagittal T1-weighted MR arthrogram (5C) demonstrates gadolinium within the tear (arrow). the intercondylar notch, most commonly to the mid ACL, and less commonly . CT arthrography is a recommended alternative for patients who are not MR eligible. 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. 300). The MRI showed complete ACL tear with displaced bucket handle medial meniscus tear. also found various MRI characteristics highly specific for detection of a recurrent tear including a line of intermediate-to-high signal or high signal through the meniscus extending into the articular surface on T2-weighted images with 95.8% specificity and change in the signal intensity pattern through the meniscus on intermediate weighted or T2-weighted images when compared to the baseline MRI with 98.2% specificity. The sagittal proton density-weighted image (2A) demonstrates increased signal intensity at the periphery of the medial meniscus posterior horn (arrow) but no fluid signal on the sagittal T2-weighted image (2B) and no gadolinium extension into this area on the MR arthrogram sagittal fat-suppressed T1-weighted arthrographic image (2C) consistent with a healed repair. The anterior horn of the menisci, especially the lateral meniscus, is an area commonly confused on MRI. Become a Gold Supporter and see no third-party ads. {"url":"/signup-modal-props.json?lang=us"}, Weerakkody Y, Baba Y, Knipe H, et al. However, few studies have directly compared the medial and lateral root tears. . Discoid lateral meniscus. Sagittal T2-weighted image (10B) reveals no fluid at the repair site. AJR Am J Roentgenol. Youderian A, Chmell S, Stull MA. pretzels dipped in sour cream. Diagnosis of meniscal tears on MRI improves when these guidelines are followed to optimize signal-to-noise ratio: high-field-strength magnets are preferable (1.5 T and stronger); a high-resolution surface coil should be used; the field of view should only encompass the necessary structures and routinely be 16 cm or less; image slices should not be too thick (34 mm); and the matrix size should be at least 256192 or higher [, A normal meniscus is low signal on all sequences. 2. Posterior meniscal root repairs: outcomes of an anatomic transtibial pull-out technique. Meniscal tears were found on MRI or arthroscopy in all 28 patients with a lateral cyst overlying the body or posterior horn of the lateral meniscus, whereas a tear was found on MRI or arthroscopy in only 14 (64%) of 22 patients with cysts adjacent to or extending to the lateral meniscus anterior horn (p = 0.006). We use cookies to create a better experience. Become a Gold Supporter and see no third-party ads. Clin Orthop Relat Res 2013; 471: pp. 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 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. MRI: When you tear your meniscus, a magnetic resonance imaging (MRI) scan will show the injury as white lines on black. The ideal technique for imaging the postoperative meniscus is a matter of active controversy and depends on the operation performed, surgeon preference and clinical question (concern for recurrent meniscal tear versus articular cartilage). What is your diagnosis? Horizontal (degenerative) tears run relatively parallel the tibial plateau. Increased intrameniscal signal is commonly seen in the transplanted allograft but does not correlate with clinical outcome. The meniscus can separate from the joint capsule or tear through the allograft. Neuschwander DC, Drez D Jr, Finney TP. 2008; 32:212219, Magee T. Accuracy of 3-Tesla MR and MR arthrography in diagnosis of meniscal retear in the post-operative knee. Bilateral complete discoid medial menisci combined with anomalous insertion and cyst formation. AJR American journal of roentgenology. Rohren EM, Kosarek FJ, Helms CA. Associated anomalies in a discoid medial A detached posterior root is functionally equivalent to a total meniscectomy with loss of its ability to withstand hoop stress. anterior horn of the medial meniscus into the anterior cruciate ligament Direct and indirect MR arthrography have been shown to be superior to conventional MRI for detection of recurrent meniscal tears in greater than 25% partial meniscectomies and meniscal repairs; however, conventional MRI is commonly used for initial evaluation of the postoperative meniscus with MR arthrography reserved for equivocal cases. an adult), and approximately twice the size of the anterior horn on The avulsed anterior horn of the lateral meniscus is flipped over and situated above the posterior horn. noted to be diminutive, with the posterior horn measuring 7 mm to 8 mm. Discoid medial meniscus. Conventional MRI is useful for evaluation of posterior root morphology at the tibial tunnel fixation site, meniscal extrusion and articular cartilage. Grade 3 is a true meniscus tear and an arthroscope is close to 100 percent accurate in diagnosing this tear. CT arthrography is recommended for patients with MRI contraindications or when extensive susceptibility artifact from hardware obscures the meniscus. Among these 26 studies of an LMRT . Intensity of signal contacting meniscal surface in recurrent tears on MR arthrography compared with that of contrast material. Dr. Michael Gabor answered Diagnostic Radiology 35 years experience No,: It doesn't sound like a bucket handle tear Klingele KE, Kocher MS, Hresko MT, et al. 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. Knee Surg Sports Traumatol Arthrosc. Kim EY, Choi SH, Ahn JH, Kwon JW. The incidence was calculated based on arthroscopic findings, and the potential secondary signs of meniscal ramp tears were evaluated on MRI. For partial meniscectomies involving 25% or more, conventional MRI has lower accuracy. Papalia R, Vasta S, Franceschi F, D'Adamio S, Maffulli N, Denaro V. Meniscal Root Tears: From Basic Science to Ultimate Surgery. Complex or deep radial tears were found in three of five cases of lateral meniscus extrusion and normal root. When interpreting MR images of the knee, it is important to assess for any change from the expected shape of the menisci. Br Med Bull. is in fact reducing the volume of the meniscus and restoring a normal (1A) Proton density-weighted, (1B) T2-weighted, and (1C) fat-suppressed T1-weighted MR arthrographic sagittal images are provided. History of a longitudinal medial meniscus tear managed by repair and concurrent ACL reconstruction. meniscus. tissue only persists at the edges, where differentiation into the History of medial meniscus posterior horn partial meniscectomy. published a case series of anterior horn tears of the lateral meniscus in 14 soccer players (mean age 20.2 years). 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 Repair of posterior root tears are being performed with increased frequency over the past several years. The trusted source for healthcare information and CONTINUING EDUCATION. They found that 76 (8%) of these indicated a tear of the anterior horn of either the medial or lateral meniscus. 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. Davidson D, Letts M, Glasgow R. Discoid meniscus in children: Treatment and outcome. Generally, discoid lateral meniscus is a relatively uncommon developmental variant slab-like configuration on sagittal MR images, with > 3 bowties They may not even be apparent with an arthroscopic examination. Monllau et al in 1998 proposed adding a fourth type, found that the absence of a line of increased signal through the meniscus extending to the articular surface on proton density and T2-weighted images was a reliable MRI finding for an untorn post-operative meniscus with 100% sensitivity. Suprapatellar plica noticed, with no related cartilaginous erosions. American Board of Orthopaedic Surgery Practice of the Orthopaedic Surgeon: Part-II, certification examination case mix. The MRI sign of a radial tear is a linear, vertical cleft of abnormal high signal at the free edge (Fig. A 22-years old male presented with injury to right knee in a road traffic accident MRI images shows double posterior horn of lateral meniscus and absent anterior horn in coronal (A: PD; B: STIR; C . Sagittal proton density-weighted image (7A) through the medial meniscus demonstrates increased signal extending to the tibial surface (arrow). Regardless of the imaging protocol chosen for evaluation of the postoperative meniscus, optimal imaging interpretation includes: The normal MRI appearance after partial meniscectomy is volume loss and morphologic change, commonly truncation or blunting of the meniscal free edge. A Study of Retrieved Allografts Used for ACL Surgery, Long-Term Results of Meniscus Allograft Transplantation with Concurrent ACL Reconstruction, Anterior Horn Meniscal Tears — Fact or Fiction, How Triathletes Can Use Cycling Cadence to Maximize Running Performance, Pharmacology Watch: HRT - Position Paper Places Benefits in Question, Clinical Briefs in Primary Care Supplement. Longitudinal lateral meniscus tear status post repair (arrow). intra-articular structures at 8 weeks gestation. 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. Media community. Surgical Outcomes Lysholm Score Unable to process the form. of the Wrisberg ligament in patients with a complete lateral discoid 3 is least common. 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. Both horns of the medial meniscus are triangular with sharp points. Kelly BT, Green DW. Seventy-four cases of bucket-handle tears (mean age, 27.2 11.3 years; 38 medial meniscus and 36 lateral meniscus; 39 concomitant anterior cruciate ligament (ACL) reconstruction) were treated with arthroscopic repair from June 2011 to August 2021. {"url":"/signup-modal-props.json?lang=us"}, El-Feky M, Flipped meniscus - anterior horn lateral meniscus. 7 Therefore, it is important for the radiologist to be familiar with the appearance of a recurrent tear versus an untorn postoperative meniscus. Fat supressed coronal proton density-weighted (19C, D) and sagittal proton density-weighted (19E) images demonstrate postoperative changes from interval posterior horn partial meniscectomy with a thin rim of posterior horn remaining (arrow) and subchondral fractures in the medial femoral condyle and medial tibial plateau (arrowheads) with marked progression of full-thickness chondral loss in the medial compartment and extruded meniscal tissue. The most frequent symptom is pain that usually begins with a minor With age, increased connective tissue stiffness of the meniscus develops secondary to elastin degradation and collagen rigidification.2. Mechanical rasping or trephination of the torn meniscus ends and parameniscal synovium is used to promote bleeding and vascular healing. Clinical imaging. 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. Radiographs are usually not diagnostic, but they may show a menisci develop from this mesenchymal tissue in a site where this tissue MRI Knee - Sagittal PDFS - Displaced meniscus Part of a torn meniscus can be displaced into another part of the knee joint In this image the anterior part of the meniscus (the anterior horn) is correctly located The posterior horn is displaced such that it is located next to the anterior horn The correct position of the posterior horn is shown A classification system developed by the International Society of Arthroscopy, Knee Surgery, and Orthopedic Sports Medicine [, Longitudinal-vertical tear. The posterior root of the lateral meniscus (PRLM) attaches along the posterior aspect of the intercondylar eminence of the tibia (Fig. 5. There is a medial and a lateral meniscus. The discoid lateral-meniscus syndrome. Ross JA,Tough ICK, English TA. Dr. Diduch, Associate Professor, Department of Orthopaedic Surgery, University of Virginia School of Medicine, Charlottesville, VA, is Editor of Sports Medicine Reports. Pathology - a tear that has developed gradually in the meniscus. A recurrent tear was proved at second look arthroscopy. Tears joint: Morphologic changes and their potential role in childhood high fibula head and a widened lateral joint space.20 Several