This arises from the posterior horn of the lateral meniscus and attaches to the lateral aspect of the medial femoral condyle. 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. MR imaging is useful for evaluation of many possible complications following meniscal surgery. Sagittal proton density-weighted image (9A) demonstrates no high signal abnormality. Disadvantages include patient discomfort, increased cost, physician time needed for the procedure and radiation exposure during fluoroscopy. the example shown (Figures 1 and 2), the entire medial meniscus is Heron, D, Bonnard C, Moraine C,Toutain A. Agenesis of cruciate What are the findings? This patient had relief after the initial repair surgery, then had a second injury with recurrent symptoms, which is why the surgeon felt this was a recurrent tear. Most horizontal tears extend to the inferior articular surface. that this rare condition is also clinically asymptomatic. To provide the highest quality clinical and technology services to customers and patients, in the spirit of continuous improvement and innovation. ISAKOS: 2023 Congress in Boston, USA : Abstract Analysis of Risk This is a well-done study with clinical correlation and adequate follow-up. typically into the anterior cruciate ligament. 1). Meniscal surgery is common and requires accurate post-operative imaging interpretation to guide the treatment approach. 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 . Normal course and intensity of both cruciate ligaments. The patient underwent partial medial meniscectomy and ACL reconstruction. You have reached your article limit for the month. Increased signal intensity at the anterior horn of the lateral meniscus was seen on the images of seven of the 11 MR studies of the volunteers. 2002;30(2):189-192. 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. The trusted source for healthcare information and CONTINUING EDUCATION. 7.2 Medial and Lateral Menisci Medial meniscus is larger than the lateral meniscus and is more "open" (=less C-like) and less wide. Radiographs are usually not diagnostic, but they may show a It is important to know the age of the patient when interpreting the MRI. Reference article, Radiopaedia.org (Accessed on 04 Mar 2023) https://doi.org/10.53347/rID-40036, {"containerId":"expandableQuestionsContainer","displayRelatedArticles":true,"displayNextQuestion":true,"displaySkipQuestion":true,"articleId":40036,"questionManager":null,"mcqUrl":"https://radiopaedia.org/articles/meniscal-root-tear/questions/1112?lang=us"}. Learn more. Association of Parameniscal Cysts With Underlying Meniscal Tears as The MRI also demonstrated moderate degenerative spurring at the lateral joint compartment, a large knee joint effusion with . An intact meniscal repair was confirmed at second look arthroscopy. Discoid lateral meniscus. Radiology. Collagen fibers are arranged for transferring compressive loads into circumferential hoop stresses, secured by radially oriented tie fibers. Diagnostic accuracy of MRI knee in reference to - ScienceDirect Repair techniques include inside-out, outside-in or all-inside approaches. noted to be diminutive, with the posterior horn measuring 7 mm to 8 mm. Get unlimited access to our full publication and article library. Normal shape and signal of the horns of the medial meniscus, with no evidence of tears or degenerations seen. morphology but lacks its posterior attachments; ie, the meniscotibial Meniscal Tear Patterns - Radsource diagnostic dilemma, as the AIMM band will be seen to extend to the Kaplan EB. At the time the article was last revised Yahya Baba had 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. Pullout fixation of posterior medial meniscus root tears: correlation between meniscus extrusion and midterm clinical results. include hypoplastic menisci, absent menisci, anomalous insertion of the 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. Resnick D, Goergen TG, Kaye JJ, et al. separate the cavity. Radiology. pretzels dipped in sour cream. Neuschwander DC, Drez D Jr, Finney TP. Increased intrameniscal signal is commonly seen in the transplanted allograft but does not correlate with clinical outcome. The example above illustrates marked degenerative changes caused by loss of meniscal function. A slightly overweight 44-year-old male sought evaluation for medial knee pain that persisted for months after running on the beach. 17. Twenty-one had ACL tears; all those with an PHLM tear had an ACL tear. MRI c spine / head jxn - they can have stenosis of foramen magnum . AJR Am J Roentgenol 211(3):519527, De Smet AA. horns to the meniscal diameter on a sagittal slice that shows a maximum Fellowship-trained musculoskeletal radiologists read 99% of the MRIs. discoid lateral meniscus is a relatively uncommon developmental variant CT arthrography is recommended for patients with MRI contraindications or when extensive susceptibility artifact from hardware obscures the meniscus. The example above demonstrates the importance of baseline MRI comparison when evaluating the postoperative meniscus. 2005; 234:5361. Sagittal proton density (PD) images through normal medial (, The medial meniscus is larger, more oblong, and normally has a larger posterior horn than anterior horn in cross section. Dr. Michael Gabor answered Diagnostic Radiology 35 years experience No,: It doesn't sound like a bucket handle tear Radial or oblique tear congurations close to or within the meniscus . menisci occurs. 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. Renew or update your current subscription to Applied Radiology. Complete radial tears, root tears and large partial meniscectomies result in markedly increased contact forces at the articular surface; and in this case, full-thickness chondral loss and subchondral fractures on both sides of the joint. 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. The meniscus may also become hypertrophic. The patient underwent a successful partial medial meniscectomy and was encouraged to seek low-impact exercise. Which meniscus is more likely to tear? The Wrisberg variant may present with a Examination showed lateral joint line tenderness and a positive McMurray sign. patella or Hoffas fat pad, and should be fairly easily differentiated Meniscal tears are common and often associated with knee pain. Magn Reson Imaging Clin N Am 2014;22(4): 517555, White LM, Schweitzer ME, Weishaupt D, Kramer J, Davis A, Marks PH. 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. The most important clinical concern at the time of MRI imaging is often high-grade articular cartilage loss. 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 body is firmly attached to the deep portion of the medial collateral ligament complex via the meniscotibial ligament. Each meniscus has three main parts, the back (posterior horn), middle (body), and front (anterior horn). MRI Findings: Medial meniscus: Tear of the posterior horn seen to the inferior articular surface continuing into the posterior body and becoming more vertical. Connolly B, Babyn PS, Wright JG, Thorner PS. We hope you found our articles A recurrent tear was proved at second look arthroscopy. Klingele KE, Kocher MS, Hresko MT, et al. posterior horn of the medial meniscus include a triangular hypointense This is a critical differentiation because the latter represents meniscal tears that can be Create a new print or digital subscription to Applied Radiology. 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. Atypically thick and high location Horizontal (degenerative) tears run relatively parallel the tibial plateau. Meniscal Roots: Current Concepts Review However, this conjecture and others pre- highest.13,27,34,42 Tear locations, such as the posterior sented in literature are mostly speculative. MRI features are consistent with torn lateral meniscus with flipped anterior horn superomedial and posterior, resting superior to the posterior horn. Reporting knee meniscal tears: technical aspects, typical pitfalls and be misinterpreted for more significant pathology on MRI. The patient failed conservative management of aspiration and cortisone injection. Type 1 is most common, and type It is believed that discoid described in thrombocytopenia absent radius syndrome (TAR syndrome).2,3 Bilateral hypoplasia of the medial meniscus has also been reported.4. Repair of posterior root tears are being performed with increased frequency over the past several years. The anterior and posterior sutures are shuttled down the tibial tunnel (arrowhead). AJR Am J Roentgenol. It can be divided into five segments: anterior horn, anterior, middle and posterior segments, and posterior horn. PDF The Menisci on MRI Pearls and Pitfalls or the Radiology Registrar The posterior root of the medial meniscus attaches to the tibia, just anterior and medial to the posterior cruciate ligament (PCL). Dr. Diduch, Associate Professor, Department of Orthopaedic Surgery, University of Virginia School of Medicine, Charlottesville, VA, is Editor of Sports Medicine Reports. In children, sometimes an increased signal is seen within meniscus due to increased vascularity, but usually the signal does not contact articular surface. What causes abnormal mobility in the medial meniscus? Pinar H, Akseki D, Karaoglan O, et al. MRI of the knee is commonly indicated for evaluation of unresolved or recurrent knee pain following meniscal surgery. And, some tears do not fill with contrast during arthrography. Posterior Horn Medial Meniscus Tears - Howard J. Luks, MD Fukuta S, Masaki K, Korai F. Prevalence of abnormal findings in magnetic resonance images of asymptomatic knees. No paralabral cyst. On examination, the patient had medial joint line tenderness with positive McMurray test. Root tears are often large radial tears that extend through the entire AP width of the meniscus. Sagittal proton density-weighted image (8A) through the medial meniscus demonstrates signal extending to the tibial surface (arrow). 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. Radial Meniscal Tear - ProScan Education - MRI Online partly divides a joint cavity, unlike articular discs, which completely 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 Rao PS, Rao SK, Paul R. Clinical, radiologic, and arthroscopic assessment of discoid lateral meniscus. The main functions How I Diagnose Meniscal Tears on Knee MRI : American Journal of Radial Tear of the Medial Meniscal Root: Reliability and Accuracy of MRI for Diagnosis. Figure 8: Medial oblique menisco-meniscal . The anomalous insertion anterior horn of the medial meniscus into the anterior cruciate ligament attachment of the posterior horn is the Wrisberg meniscofemoral 2006; 88:660667, Boutin RD, Fritz RC, Marder RA. Irrespective of the repair approach or repair devices used, diagnostic criteria for a recurrent tear remains the same fluid signal or contrast extending into the meniscal substance. Am J Sports Med 2017; 45:884891, Zaffagnini S, Grassi A, Marcheggiani Muccioli GM, et al. The reported prevalence is 0.06% to 0.3%.25 MRI failed to detect anterior horn injury of lateral meniscus in six (16.7%) cases, all of which were longitudinal fissure in the red zone. The anterior and posterior meniscofemoral ligaments (Humphrey and Wrisberg respectively) are commonly present with one or both found in 93-100% of patients. The posterior cruciate ligament is intact. Thirty-one of these patients underwent subsequent arthroscopic evaluation to allow clinical correlation. 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. Kijowski et al. MRIs of BHT may have several characteristic appearances including (1) fragment in the notch sign; (2) double anterior horn sign, in which there is an additional meniscal fragment in the anterior joint on top of the native anterior horn; (3) the absent bow tie sign; (4) the double PCL sign, in which the centrally displaced fragment lies just anterior and parallel to the PCL giving the appearance of two PCLs; and (5) the coronal truncation sign, in which the free edge of the meniscal body appears clipped off on coronal images (Fig. The patient underwent an all-inside lateral meniscus repair. Arthroscopy for Medial Meniscus Tears The decision to repair or remove the torn portion is made at the time of surgery. of the Wrisberg ligament in patients with a complete lateral discoid during movement, and less commonly joint-line tenderness, reduced With age, increased connective tissue stiffness of the meniscus develops secondary to elastin degradation and collagen rigidification.2. pivoting). Still, many clinicians choose to use conventional MRI for initial postoperative imaging which may show displaced meniscal fragments, new tears in different locations or internal derangement not involving the meniscus. The MRI revealed a longitudinal tear in the posterior horn of the lateral meniscus. Medial meniscus bucket handle tears can result in a double PCL sign. mesenchymal mass that differentiates into the tibia, femur, and menisci develop from this mesenchymal tissue in a site where this tissue The most common Generally, Weight-bearing knee X-rays showed a 50 % narrowing in the medial compartment. Total meniscectomy is rarely performed unless the meniscus is so severely damaged that no salvageable meniscal tissue remains. Become a Gold Supporter and see no third-party ads. Biologic augmentation with application of exogenous fibrin clot or growth factors may be combined with the repair to promote healing. There was no evidence of meniscal extrusion or a meniscal ghost sign (Fig. Because this is a relatively new procedure, few studies have been dedicated to MRI evaluation of postoperative root repair. They often tend to be radial tears extending into the meniscal root. meniscus is partial meniscal excision, leaving a 6- to 7-mm peripheral We will review the common meniscal variants, which 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. 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. Rohren EM, Kosarek FJ, Helms CA. Methods Eighteen patients who had arthroscopically confirmed partial MMPRTs were included. discoid lateral meniscus, including a propensity for tears to occur and 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. ligament and meniscal fascicles. History of medial meniscus posterior horn partial meniscectomy. Singh K, Helms CA, Jacobs MT, Higgins LD. 2013;106(1):91-115. However, the tear changes plane of orientation over its course. Ross JA,Tough ICK, English TA. for the ratio of the sum of the width of the anterior and posterior 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. A Figure 7: Meniscofemoral ligament. Anterior horn of the lateral meniscus: another potential pitfall in MR acromioclavicular, sternoclavicular, and temporomandibular joints. this may extend to to the mid body." is this a bucket tear?