At the time the case was submitted for publication Mostafa El-Feky had no recorded disclosures. Lee S, Jee W, Kim J. 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. The anterior horn inserts on the tibia and continues laterally to the anterior horn of the lateral meniscus via the transverse intermeniscal ligament. Discoid meniscus in children: Magnetic resonance imaging characteristics. Clin Orthop Relat Res 2013; 471: pp. 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. The anterior horn of the menisci, especially the lateral meniscus, is an area commonly confused on MRI. from AIMM. Pain is typically medial and activity-related (e.g. Kocher MS, Klingele K, Rassman SO. An intact meniscal repair was confirmed at second look arthroscopy. 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 Comparison of Postoperative Antibiotic Regimens for Complex Appendicitis: Is Two Days as Good as Five Days? Anterior lateral cysts extended . MR criteria are used to make the diagnosis. Meniscal root tears are a form of radial tear that involves the central attachment of the meniscus (12a). The MRI revealed a vertical flap (oblique) tear of the medial meniscus. Medial meniscus posterior horn peripheral longitudinal tear (arrow) seen on the sagittal proton density-weighted image (15A) and managed by repair. The trusted source for healthcare information and CONTINUING EDUCATION. Objectives: Low-field MRI at 0.55 Tesla (T) with deep learning image reconstruction has recently become commercially available. As a result, the accuracy rate of diagnosis by MRI is 83.3%. On examination, there was marked medial joint line tenderness and a large effusion. However, this conjecture and others pre- highest.13,27,34,42 Tear locations, such as the posterior sented in literature are mostly speculative. How I Diagnose Meniscal Tears on Knee MRI. It is believed that discoid The meniscal repair is intact. There ligament and meniscal fascicles. It is often explained by fibers of the anterior cruciate ligament and the covering synovium . If the tear does not show, it is considered a Grade 1 or 2 and is not as serious. Learn more. ADVERTISEMENT: Radiopaedia is free thanks to our supporters and advertisers. Vertical flap (oblique, flap, parrots beak) tears are unstable tears and occur in younger patients. Sagittal proton density-weighted image (8A) through the medial meniscus demonstrates signal extending to the tibial surface (arrow). 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 In these cases, MR arthrography may provide additional diagnostic utility. This arises from the posterior horn of the lateral meniscus and attaches to the lateral aspect of the medial femoral condyle. Meniscal transplant is usually reserved for patients younger than 50 years who have normal axial alignment. of the transverse ligament is comparable to the general population.5. 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. Extension to the anterior cortex of . pivoting). Symptoms of anterior horn tears were very similar to those of meniscal tears of the midbody or posterior horn, including catching, pain with knee flexion, and swelling. There is no telling how much this error rate will change for radiologists less experienced with MRI. Imaging characteristics of the Tachibana Y, Yamazaki Y, Ninomiya S. Discoid medial meniscus. CT arthrography may be used to evaluate the postoperative meniscus when MRI is contraindicated. Bilateral complete discoid medial menisci combined with anomalous insertion and cyst formation. Type 2: An incomplete slab of meniscal tissue with 80% coverage of the lateral tibial plateau. Findings indicate an intact meniscus following partial meniscectomy with normal intrameniscal signal. History of medial meniscus posterior horn and body partial meniscectomy. reported.4. Discoid lateral meniscus in children. Materials and methods . is in fact reducing the volume of the meniscus and restoring a normal posterior fascicles and meniscotibial ligament are absent and a high ligament, and the posterior horn may translate or rotate due to Both the healed peripheral tear and the new central tear were proved at second look arthroscopy. (1A) Proton density-weighted, (1B) T2-weighted, and (1C) fat-suppressed T1-weighted MR arthrographic sagittal images are provided. Neuschwander DC, Drez D Jr, Finney TP. The medial compartment articular cartilage is preserved, and the meniscal body is not significantly extruded (16D). Create a new print or digital subscription to Applied Radiology. . Analytical, Diagnostic and Therapeutic Techniques and Equipment 13. The medial meniscus is more tightly anchored than the lateral meniscus, allowing for approximately 5mm of anterior-posterior translation. 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. On MRI, they resemble radial tears, with a linear cleft of abnormal signal seen at the free edge. Horizontal (degenerative) tears run relatively parallel the tibial plateau. Repair techniques include inside-out, outside-in or all-inside approaches. They may not even be apparent with an arthroscopic examination. The patient failed conservative management of aspiration and cortisone injection. Dr. Michael Gabor answered Diagnostic Radiology 35 years experience No,: It doesn't sound like a bucket handle tear For DSR inquiries or complaints, please reach out to Wes Vaux, Data Privacy Officer, The menisci are C-shaped fibrocartilaginous structures composed of radial and circumferential collagen fibers that have several roles, including joint stabilization, load distribution, articular cartilage protection and joint lubrication. Sagittal proton density-weighted image (9A) demonstrates no high signal abnormality. The medial meniscus covers 60% of the medial compartment. Type AJR Am J Roentgenol. 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. medial meniscus, discoid lateral meniscus, including the Wrisberg Normal course and intensity of both cruciate ligaments. 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 2011; 19:147157, Gwathmey F.W., Golish S.R., Diduch D.R., et al: Complications in brief: meniscus repair. Skeletal radiology. structure on sagittal images on T1, proton density, and fat-saturated Thirty-one of these patients underwent subsequent arthroscopic evaluation to allow clinical correlation. Intensity of signal contacting meniscal surface in recurrent tears on MR arthrography compared with that of contrast material. Because most meniscal tears are not isolated to the red zone, it is understandable that most meniscal surgeries are partial meniscectomies which aim to restore meniscus stability while preserving as much native meniscal tissue as possible, to decrease the risk of osteoarthritis. They often tend to be radial tears extending into the meniscal root. There was no evidence of meniscal extrusion or a meniscal ghost sign (Fig. Davidson D, Letts M, Glasgow R. Discoid meniscus in children: Treatment and outcome. Radiology. The MFL was not observed in five (19%) of 26 studies of an LMRT. ligaments and menisci causing severe knee dysplasia in TAR syndrome. | 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 tear. 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). 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. 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? Arthroscopy revealed a horizontal tear of PHMM, and a partial medial meniscectomy was performed. 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. problem in practice. Repair devices including arrows, darts and sutures are used to approximate the torn edges of the meniscus. 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. posterior horn usually measures 12 mm to 16 mm in the sagittal plane in Magnetic Resonance Imaging Arthroscopy Orthodontic Extrusion Anterior Cruciate Ligament Reconstruction Arthroscopes Suture Anchors Tissue Culture Techniques Tissue Engineering Injections, Intra-Articular Range of Motion, Articular Arthrography Hardness Tests Orthopedic Procedures asymptomatic, although there is a greater propensity for discoid menisci Symptomatic anomalous insertion of the medial meniscus. 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. runs from the anterior horn of the medial meniscus to either the ACL or 70 year-old female with history of medial meniscus posterior horn radial tear. Thompson WO, Thaete FL, Fu FH, Dye SF. Kim SJ, Moon SH, Shin SJ. of a case of discoid medial cartilage, with an embryological note. 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. Discoid lateral meniscus and the frequency of meniscal tears. Arthroscopy for Medial Meniscus Tears The decision to repair or remove the torn portion is made at the time of surgery. Best assessed on T2 weighted sequences. In the U.S., intraarticular injection of gadolinium-based contrast is off label. published a case series of anterior horn tears of the lateral meniscus in 14 soccer players (mean age 20.2 years). the example shown (Figures 1 and 2), the entire medial meniscus is A slightly overweight 44-year-old male sought evaluation for medial knee pain that persisted for months after running on the beach. Sagittal proton density-weighted image (5B) through the medial meniscus at age 17 reveals an incomplete tibial surface longitudinal tear (arrow) in a new location and orientation. 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 . menisci develop from this mesenchymal tissue in a site where this tissue Among these 26 studies of an LMRT . Normal Of those 31 patients who underwent arthroscopic examination, there were only 8 true anterior horn tears (26% true positive rate) and 18 had normal or intact menisci in all zones. Schwenke M, Singh M, Chow B Anterior Cruciate Ligament and Meniscal Tears: A Multi-modality Review. 36 year old male with history of meniscus surgery 7 years ago. Shepard and colleagues at UCLA specifically analyzed this by reviewing 947 consecutive MRIs. Synopsis: In a consecutive series of nearly 1000 knee MRIs, there was a 74% false-positive rate for the diagnosis of anterior horn meniscal tears. 2002;30(2):189-192. Anterior tibial marrow edema and organized trabecular fracture measuring 16 mm AP, 18 mm transverse. 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. This case is almost identical to the previous case with a different clinical history. Recent evidence suggests that decreased extrusion may correlate to better clinical outcomes.18. These features constitute O'Donoghue unhappy triad. Lateral meniscus tears of the posterior root are a common concomitant injury to anterior cruciate ligament (ACL) tears [6, 16, 20]. Congenital discoid cartilage. The prevalence of a medial discoid meniscus in patients with AIMM {"url":"/signup-modal-props.json?lang=us"}, Weerakkody Y, Baba Y, Knipe H, et al.
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