incomplete breakdown of the central meniscus, but this is now disputed, with mechanical features of clicking and locking. An intact meniscal repair was confirmed at second look arthroscopy. You have reached your article limit for the month. The articular cartilage is well seen on the pre-operative sagittal proton density-weighted image (19B). It is possible that there could have been some tears missed at arthroscopy that were on the undersurface of the anterior horn, an area which is extremely difficultif not impossibleto visualize. Examination of the knee showed a mild effusion, 1+ Lachman, positive Pivot shift, and mild tenderness to both medial and lateral joint lines. Efficacy of Arthroscopic Treatment for Concurrent Medial Meniscus However, the use of MRI arthrography should be considered for post-operative menisci with equivocal findings on conventional MRI as the presence of high gadolinium-like signal within the meniscus would allow for a definitive diagnosis of re-tear. variant, and discoid medial meniscus. 800-688-2421. 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. One of the most frequent indications for arthroscopic knee surgery is a meniscal tear.1 It is estimated that 1 million meniscus surgeries are performed in the U.S. annually with 4 billion dollars in associated direct medical expenditures.2 Meniscal surgeries include partial meniscectomy, meniscal repair and meniscal replacement. may simulate a peripheral tear (Figure 6).23 The only ADVERTISEMENT: Supporters see fewer/no ads. He presented after a few months with symptoms of instability. 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. 2012;199(3):481-99. This case is almost identical to the previous case with a different clinical history. 3 years later the sagittal proton density-weighted image (15B) shows a healed posterior horn (arrow) with a new flap tear in the medial meniscus anterior horn (arrowhead). Nakajima T, Nabeshima Y, Fujii H, et al. Arthroscopy for Medial Meniscus Tears The decision to repair or remove the torn portion is made at the time of surgery. Kelly BT, Green DW. 300). Of these patients treated nonoperatively, 6 had a diagnosis of an isolated anterior horn tear on MRI. 3. congenital absence of the cruciate ligaments. The lateral meniscus is produced by the varus tension and tibial IR. For partial meniscectomies involving 25% or more, conventional MRI has lower accuracy. snapping knee due to hypermobility. They found that 76 (8%) of these indicated a tear of the anterior horn of either the medial or lateral meniscus. Discoid lateral meniscus APPLIED RADIOLOGY Otherwise, the increased vascularity in children has sometimes led to false-positive reading of a meniscus tear. 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 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. CT arthrography is a recommended alternative for patients who are not MR eligible. Meniscus Tear MRI Correlation | SpringerLink The lateral meniscus is more circular, and its anterior and posterior horns are nearly equivalent in size in cross section. History of medial meniscus posterior horn and body partial meniscectomy. The most commonly practiced On imaging alone, the radiologist may not be able to distinguish a residual tear (failed repair) from a recurrent tear in the same location. A tear was found and the repair was revised at second look arthroscopy. Arthroscopy revealed a horizontal tear of PHMM, and a partial medial meniscectomy was performed. 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. AJR Am J Roentgenol 2009;193:515-523. Youderian A, Chmell S, Stull MA. These are like large radial tears and can destabilize a large portion of the meniscus. On sagittal proton-density and T2-weighted images, this lesion was demonstrated by sensitive but nonspecific signs, such as the flipped meniscus . Fat suppressed sagittal T1-weighted MR arthrogram (5C) demonstrates gadolinium within the tear (arrow). Lateral meniscus tears of the posterior root are a common concomitant injury to anterior cruciate ligament (ACL) tears [6, 16, 20]. Kim SJ, Moon SH, Shin SJ. The example above demonstrates the importance of baseline MRI comparison when evaluating the postoperative meniscus. Tears can be characterized by length, depth, shape, gap, displacement, stability, dysplasia (discoid) By comparison, the complication rate for ACL reconstruction is 9% and PCL reconstruction is 20%.20 Potential complications associated with arthroscopic meniscal surgery include synovitis, arthrofibrosis, chondral damage, meniscal damage, MCL injury, nerve injury (saphenous, tibial, peroneal), vascular injury, deep venous thrombosis and infection.21 Progression of osteoarthritis and stress related bone changes are seen with increased frequency in the postoperative knee, particularly with larger partial meniscectomies. Interested in Group Sales? Unable to process the form. The congenitally absent meniscus appears to influence the development 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 17. 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. An intact meniscal repair was confirmed at second look arthroscopy. Both the healed peripheral tear and the new central tear were proved at second look arthroscopy. ISAKOS: 2023 Congress in Boston, USA : Abstract Analysis of Risk Collagen fibers are arranged for transferring compressive loads into circumferential hoop stresses, secured by radially oriented tie fibers. The torn edges are aligned, and stable fixation applied with sutures or bioabsorbable implants at approximately 5 mm intervals. The shape of the meniscus is formed at the eighth week of Lateral Meniscus Tear | New Health Advisor On MRI, longitudinal tears appear as a vertical line of abnormal signal contacting articular surface. problem in practice. It has been calculated that the lateral meniscus absorbs about 70% of the forces across the lateral compartment of the knee. patella or Hoffas fat pad, and should be fairly easily differentiated horns to the meniscal diameter on a sagittal slice that shows a maximum of the anterior horn of the medial meniscus, an inferior patella plica, Following partial meniscectomy, the knee is at increased risk for osteoarthritis. On the proton density-weighted image (12A) persistent high signal extends to the tibial and femoral surfaces (arrow). 1). Grade 3 is a true meniscus tear and an arthroscope is close to 100 percent accurate in diagnosing this tear. Tears On MRI, they resemble radial tears, with a linear cleft of abnormal signal seen at the free edge. A tear of the meniscal root means the tear is near where it attaches to the bone, usually far in the back. 3 is least common. They maintain a relatively constant distance from the periphery of the meniscus [. Longitudinal lateral meniscus tear status post repair (arrow). of the Wrisberg ligament in patients with a complete lateral discoid Lateral Meniscus Tear | Symptoms, Causes and Diagnosis to the base of the ACL or the intercondylar notch. The MRI also demonstrated moderate degenerative spurring at the lateral joint compartment, a large knee joint effusion with . Sagittal T2-weighted (18B) and fat-suppressed sagittal proton density-weighted sagittal (18C) images demonstrate fluid-like signal in the posterior horn suggestive of a recurrent tear. Surgery Needed?? : r/MeniscusInjuries Discoid lateral meniscus of the knee joint: Nature, mechanism, and operative treatment. Results: Arthroscopic examination of the anterior horn of the lateral meniscus in all 22 patients was normal. Kim SJ, Choi CH. of the meniscus. medial meniscus, and not be confined to the ACL as seen in an ACL tear. For DSR inquiries or complaints, please reach out to Wes Vaux, Data Privacy Officer, ; Lee, S.H. The common insertion of the anterior cruciate ligament (ACL) and the AHLM root may provide a pathway for disease. 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. Anterior lateral cysts extended . Meniscal root tears are a type of meniscal tear in the knee where the tear extends to either the anterior or posterior meniscal root attachment to the central tibial plateau. 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. Meniscal root tearsare a type of meniscal tearin the knee where the tear extends to either the anterior or posterior meniscal root attachment to the central tibial plateau. 36 year old male with history of meniscus surgery 7 years ago. Rohren EM, Kosarek FJ, Helms CA. 2020;49(1):42-49. Of the 54 participants, 5 had PHLM tears and 49 were normal. measurements of the posterior horn of the medial meniscus may vary, but Anterior horn of the lateral meniscus: another potential - PubMed The meniscal body is firmly attached to the deep portion of the medial collateral ligament complex via the meniscotibial ligament. 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. These include looking for a Special thanks to David Rubin, MD for providing several cases used in this web clinic. (PDF) Sensitivity and Specificity of MRI in Diagnosing Concomitant 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. Tachibana Y, Yamazaki Y, Ninomiya S. Discoid medial meniscus. The meniscus is two crescent-shaped, thick pieces of cartilage that sit in the knee between the tibia and the femur. the example shown (Figures 1 and 2), the entire medial meniscus is Menisci are present in the knees and the Grades 1 and 2 are not considered serious. Rao PS, Rao SK, Paul R. Clinical, radiologic, and arthroscopic assessment of discoid lateral meniscus. Bilateral discoid medial menisci: Case report. Bucket-handle tear of the lateral meniscus: Flipped meniscus sign Pinar H, Akseki D, Karaoglan O, et al. . tissue only persists at the edges, where differentiation into the Most lateral meniscal tears are due to twisting or turning activities or falls. The meniscus can separate from the joint capsule or tear through the allograft. Pain is typically medial and activity-related (e.g. What are the findings? 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. Shepard and colleagues at UCLA specifically analyzed this by reviewing 947 consecutive MRIs. variants of the meniscus are relatively uncommon and are frequently The prevalence of a medial discoid meniscus in patients with AIMM However, clinically significant tears that can mechanically impinge were unlikely to have been missed. Considered a feature of knee osteoarthritis. ADVERTISEMENT: Radiopaedia is free thanks to our supporters and advertisers. 2012;20(10):2098-103. Ross JA,Tough ICK, English TA. Normal shape and signal of the horns of the medial meniscus, with no evidence of tears or degenerations seen. The sagittal proton density-weighted image (13A) demonstrates linear high signal extending to the femoral and tibial surfaces (arrow). Note that signal does not contact articular surface, The most common criterion for diagnosing meniscus tear on MRI is an increased signal extending in a line or band to the articular surface. O'Donoghue unhappy triad | Radiology Case | Radiopaedia.org 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. Kijowski et al. 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. Total meniscectomy is rarely performed unless the meniscus is so severely damaged that no salvageable meniscal tissue remains. meniscus | Search | Radiopaedia.org Arthroscopy: The Journal of Arthroscopic & Related Surgery. A meta-analysis of 44 trials. No gadolinium extension into the meniscus on fat-suppressed sagittal T1-weighted (9B) post arthrogram view. Disadvantages include risks associated with joint injection, radiation exposure and lower contrast resolution compared to MRI, particularly in the extraarticular soft tissues. Anterior tibial marrow edema and organized trabecular fracture measuring 16 mm AP, 18 mm transverse. The discoid lateral-meniscus syndrome. MRI showed posterior horn of the medial meniscus (PHMM) horizontal tear with early degenerative changes. AJR Am J Roentgenol. Discoid medial meniscus. On the sagittal fat-suppressed T2-weighted image (7B), fluid extends into the tear. both enjoyable and insightful. Symptomatic anomalous insertion of the medial meniscus. Case study, Radiopaedia.org (Accessed on 04 Mar 2023) https://doi.org/10.53347/rID-75066. Davidson D, Letts M, Glasgow R. Discoid meniscus in children: Treatment and outcome. the medial meniscus. Magnetic resonance imaging (MRI), was performed in another facility and, showed normal medial and lateral menisci except for the absence of a medial posterior root insertion both on coronal and on sagittal images. 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. Most horizontal tears extend to the inferior articular surface. Root tears are often large radial tears that extend through the entire AP width of the meniscus. 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. Clin Orthop Relat Res 2012; 470: pp. Anterior horn of the lateral meniscus: another potential pitfall in MR imaging of the knee. (Figure 1). The ends of the anterior and posterior horns are firmly attached to the tibia at their roots. An algorithm for computing tear meniscus profile Clin Orthop Relat Res 2013; 471: pp. Disadvantages include increased cost, increased patient time, potential for adverse reactions to contrast agent compared to conventional MRI and lack of joint distention. Disadvantages include patient discomfort, increased cost, physician time needed for the procedure and radiation exposure during fluoroscopy. It is often explained by fibers of the anterior cruciate ligament and the covering synovium . Sagittal PD (. menisci (Figure 8). Lateral meniscus tears of the posterior root are a common concomitant injury to anterior cruciate ligament (ACL) tears [6, 16, 20]. varus deformity (Figure 3). Note the symmetrical shape of the lateral meniscus (left) with similar size of the anterior and posterior horns. Learn more. They are usually due to an acute injury [. Mild irregularities of the meniscal contour may be present, particularly in the first 6-9 months after surgery which tend to smooth out and remodel over time.15 For partial meniscectomies involving less than 25% of the meniscus, conventional MRI is used with the same imaging criteria for evaluating a tear as the native meniscus linear intrasubstance increased signal extending to the articular surface, visualized on 2 images, either consecutively in the same orientation or in the same region in 2 different planes or displaced meniscal fragment (based on the assumption that imaging is spaced at 3 mm intervals). posterior horn usually measures 12 mm to 16 mm in the sagittal plane in Associated anomalies in a discoid medial Meniscal extrusion. Medical search. Web Clark CR, Ogden JA. Pre-operative fat supressed coronal proton density-weighted image (19A) demonstates a posterior root radial tear (arrow). Kim EY, Choi SH, Ahn JH, Kwon JW. Meniscal Tear Patterns - Radsource 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. . Each meniscus has three main parts, the back (posterior horn), middle (body), and front (anterior horn). Type 1 is most common, and type runs from the anterior horn of the medial meniscus to either the ACL or Anomalous insertion of anterior and posterior horns of medial meniscus Unable to process the form. Medial meniscus bucket handle tears can result in a double PCL sign. The MRI revealed a vertical flap (oblique) tear of the medial meniscus. 6 months post-operative she had increased pain prompting follow-up MRI. The posterior cruciate ligament is intact. 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). Studies on meniscus root tears have investigated the relationship of osteoarthritis and an anterior cruciate ligament tear. Meniscus tears, indicated by MRI, are classified in three grades. A previous study by De Smet et al. 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. noted to be diminutive, with the posterior horn measuring 7 mm to 8 mm. Recent evidence suggests that decreased extrusion may correlate to better clinical outcomes.18. When evaluating a portion of the meniscus that is in a different location than the repair, criteria for evaluating a virgin meniscus may be used for that area. 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. In The meniscus may also become hypertrophic. We use cookies to create a better experience. PDF The Menisci on MRI Pearls and Pitfalls or the Radiology Registrar 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. CT arthrography is recommended for patients with MRI contraindications or when extensive susceptibility artifact from hardware obscures the meniscus. 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. 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. The main functions Grade II hyperintense horizontal signal of posterior horn of medial meniscus is noted. Meniscal tears are common and often associated with knee pain. Best assessed on T2 weighted sequences. Discoid lateral meniscus was originally believed to result from an Am J Sports Med. Incidence and Detection of Meniscal Ramp Lesions on Magnetic Resonance Radial Tear of the Medial Meniscal Root: Reliability and Accuracy of MRI for Diagnosis. Close clinical correlation is advised before recommending surgery based on this finding alone. 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 ligaments and menisci causing severe knee dysplasia in TAR syndrome. The posterior root lies anterior to the posterior cruciate ligament. 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. Midterm results in active patients. Extension to the anterior cortex of . 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? It splits into two bands at the PCL, named Humphry(anterior to the PCL) and Wrisberg (posterior to the PCL). Click to share on Twitter (Opens in new window), Click to share on Facebook (Opens in new window), Click to share on Google+ (Opens in new window), Posterior Instability and Labral Pathology, Imaging Evaluation of the Painful or Failed Shoulder Arthroplasty, Other Entities: PLRI, HO, Triceps, and Plica, MRI-Arthroscopy Correlations in the Overhead Athlete, Acetabular Fossa, Femoral Fovea, and the Ligamentum Teres. described in thrombocytopenia absent radius syndrome (TAR syndrome).2,3 Bilateral hypoplasia of the medial meniscus has also been reported.4. Volunteerism and Sports Medicine: Where do We Stand? The patient had a recent new injury with increased pain. 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 [ 8, 11, 12 ]. 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. The lateral meniscus is one of two fibrocartilaginous menisci of the knee. signal fluid cleft interposed between the posterior horn and the capsule Coronal extrusion of the lateral meniscus does not increase after A 2003 systematic review of the literature, in which 29 publications met strict inclusion criteria, demonstrated pooled weighted sensitivity and specificity of 93.3 % and 88.4 % for the medial meniscus and 79.3 % and 95.7 % for the lateral meniscus, respectively [, Most meniscal tears are visible and best seen on sagittal images. Both horns of the medial meniscus are triangular with sharp points. {"url":"/signup-modal-props.json?lang=us"}, Weerakkody Y, Baba Y, Knipe H, et al. [emailprotected]. 2006; 187:W565568. Financial Disclosure: None of the authors or planners for this educational activity have relevant financial relationships to disclose with ineligible companies whose primary business is producing, marketing, selling, reselling, or distributing healthcare products used by or on patients. How I Diagnose Meniscal Tears on Knee MRI. Lateral meniscus extrusion was present in six (23%) of 26 LMRTs and five (2.2%) of 231 patients with normal meniscus roots ( P < .001). This case features the following signs of meniscal tear: Case courtesy, Prof. Dr. Khaled Matrawy, Professor of radiology, Alexandria university, Egypt. The most common location is the anterior horn-body junction of the lateral meniscus and less commonly in the mid posterior horn or root of the medial meniscus. Exam showed a mild effusion and medial joint line tenderness. If a meniscus tear shows up on a MRI, it is considered a Grade 3. Become a Gold Supporter and see no third-party ads. show cupping of the medial tibial plateau, proximal medial tibial physis 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.