incomplete breakdown of the central meniscus, but this is now disputed, Meniscus tears, indicated by MRI, are classified in three grades. tissue only persists at the edges, where differentiation into the {"url":"/signup-modal-props.json?lang=us"}, El-Feky M, Flipped meniscus - anterior horn lateral meniscus. Create a new print or digital subscription to Applied Radiology. MRI: When you tear your meniscus, a magnetic resonance imaging (MRI) scan will show the injury as white lines on black. published a case series of anterior horn tears of the lateral meniscus in 14 soccer players (mean age 20.2 years). In the U.S., intraarticular injection of gadolinium-based contrast is off label. History of longitudinal medial meniscus tear managed by meniscal repair (arrows). By continuing to use our site, you consent to the use of cookies outlined in our Privacy Policy. Indications for meniscal repair typically include posttraumatic peripheral (red zone) longitudinal tears located near the joint capsule, ideally in younger patients (less than 40). Fat suppressed sagittal T1-weighted MR arthrogram (5C) demonstrates gadolinium within the tear (arrow). 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. 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. Long-term outcome after arthroscopic meniscal repair versus arthroscopic partial meniscectomy for traumatic meniscal tears. PDF The Menisci on MRI Pearls and Pitfalls or the Radiology Registrar 4. 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 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. 2a, 2b, 2c). 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 . MR criteria for discoid lateral menisci are used for discoid medial In children, sometimes an increased signal is seen within meniscus due to increased vascularity, but usually the signal does not contact articular surface. Br Med Bull. They often tend to be radial tears extending into the meniscal root. MR arthrogram fat-suppressed sagittal T1-weighted image (11C) shows no gadolinium in the repair. 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? Samoto N, Kozuma M, Tokuhisa T, Kobayashi K. Diagnosis of discoid lateral meniscus of the knee on MR imaging. Nakajima T, Nabeshima Y, Fujii H, et al. discoid meniscus, although discoid medial menisci can occur much less Healed peripheral medial meniscus posterior horn repair and new longitudinal tear in a different location. Pinar H, Akseki D, Karaoglan O, et al. Kocher MS, Klingele K, Rassman SO. Because this is a relatively new procedure, few studies have been dedicated to MRI evaluation of postoperative root repair. Am J Sports Med 2017; 45:884891, Zaffagnini S, Grassi A, Marcheggiani Muccioli GM, et al. Connolly B, Babyn PS, Wright JG, Thorner PS. And, some tears do not fill with contrast during arthrography. with mechanical features of clicking and locking. 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 Lee S, Jee W, Kim J. A displaced longitudinal tear is a "bucket handle" tear. The posterior root lies anterior to the posterior cruciate ligament. To provide the highest quality clinical and technology services to customers and patients, in the spirit of continuous improvement and innovation. 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. They often tend to be radial tears extending into the meniscal root. Normal They maintain a relatively constant distance from the periphery of the meniscus [. Medial meniscus posterior horn peripheral longitudinal tear treated with repair. Atypically thick and high location The lateral meniscus is more circular, and its anterior and posterior horns are nearly equivalent in size in cross section. posterior horn of the medial meniscus include a triangular hypointense Of the 54 participants, 5 had PHLM tears and 49 were normal. 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. When bilateral, they are usually symmetric. 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. Report 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. The MRI showed complete ACL tear with displaced bucket handle medial meniscus tear. 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. Following partial meniscectomy, the knee is at increased risk for osteoarthritis. One important reason for such discrepancies is a failure to understand the transverse geniculate ligament of the knee (TGL). Discoid lateral meniscus (DLM) is a common anatomic variant in the knee typically presented in young populations, with a greater incidence in the Asian population than in other populations. 2002;30(2):189-192. morphology. Congenital discoid cartilage. They were first described by M J Pagnaniet al. In some patients, hyperintense signal may persist at the repair site on conventional MRI for several years and is thought to represent granulation tissue. Sagittal proton density-weighted image (5A) through the medial meniscus at age 12 shows the initial horizontal tear in the posterior horn (arrow) subsequently treated with partial meniscectomy. Variations in meniscofemoral ligaments at anatomical study and MR imaging. 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 An alternative way of fastening the allograft to the donor knee involves harvesting the meniscus with a small bone plug attached to each root and then securing the plugs within osseous tunnels drilled in the recipient tibia. The patient subsequently underwent successful partial medial meniscectomy. The articular cartilage is well seen on the pre-operative sagittal proton density-weighted image (19B). of the anterior horn of the medial meniscus, an inferior patella plica, Zonal variation is also seen in the density of meniscus cells and their phenotypes with a chondrocytic inner zone and fibroblastic outer zone. (as previously described), meniscal cyst,26 discoid lateral meniscus in the same knee (Figure 9),25 and pathologic medial patella plica.27. of the transverse ligament is comparable to the general population.5. Illustration of the transtibial pullout repair for a tear of the posterior horn medial meniscal root (arrow). no financial relationships to ineligible companies to disclose. 4). 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. 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 . A detached posterior root is functionally equivalent to a total meniscectomy with loss of its ability to withstand hoop stress. 2020;49(1):42-49. To assess the prevalence of meniscal extrusion and its . De Smet A. {"url":"/signup-modal-props.json?lang=us"}, Weerakkody Y, Baba Y, Knipe H, et al. of the distal femur and proximal tibia, and in the case report of Lateral Meniscus Tear | Symptoms, Causes and Diagnosis an adult), and approximately twice the size of the anterior horn on trauma; however, other symptoms include clicking, snapping, and locking The ends of the anterior and posterior horns are firmly attached to the tibia at their roots. noted to be diminutive, with the posterior horn measuring 7 mm to 8 mm. Suprapatellar plica noticed, with no related cartilaginous erosions. Figure 7: Meniscofemoral ligament. History of medial meniscus posterior horn and body partial meniscectomy. 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. Results: Arthroscopic examination of the anterior horn of the lateral meniscus in all 22 patients was normal. is much greater than in a discoid lateral meniscus, and the prevalence You have reached your article limit for the month. the intercondylar notch, most commonly to the mid ACL, and less commonly If a horizontal tear involves a long segment of the meniscus, the central fragment may displace centrally from the peripheral portion of the meniscus [, Bucket handle tears (BHT) often cause pain and mechanical symptoms, such as locking, catching, and giving way [. meniscus. Grade II hyperintense horizontal signal of posterior horn of medial meniscus is noted. Volunteerism and Sports Medicine: Where do We Stand? These tears are usually degenerative in nature and usually not associated with a discrete injury [. Anatomic variability and increased signal change in this area are commonly mistaken for tears. The meniscus is two crescent-shaped, thick pieces of cartilage that sit in the knee between the tibia and the femur. Bucket-handle tear of the lateral meniscus: Flipped meniscus sign Knee Surg Sports Traumatol Arthrosc 2011; 19:147157, Gwathmey F.W., Golish S.R., Diduch D.R., et al: Complications in brief: meniscus repair. The Knee Resource | Degenerative Meniscus Tear described in thrombocytopenia absent radius syndrome (TAR syndrome).2,3 Bilateral hypoplasia of the medial meniscus has also been reported.4. No gadolinium extension into the meniscus on fat-suppressed sagittal T1-weighted (9B) post arthrogram view. This arises from the posterior horn of the lateral meniscus and attaches to the lateral aspect of the medial femoral condyle. (Tr. Reporting knee meniscal tears: technical aspects, typical pitfalls and Meniscal tears are common and often associated with knee pain. Clin Orthop Relat Res 2013; 471: pp. ligaments and menisci causing severe knee dysplasia in TAR syndrome. About KOL ; Learn more about our technology and how more and more universities, research organizations, and companies in all industries are using our data to lower their costs. On the proton density-weighted image (12A) persistent high signal extends to the tibial and femoral surfaces (arrow). Extension to the anterior cortex of . 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 ]. 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 . joint: Morphologic changes and their potential role in childhood the medial meniscus. discoid lateral meniscus, including a propensity for tears to occur and 70 year-old female with history of medial meniscus posterior horn radial tear. The common insertion of the anterior cruciate ligament (ACL) and the AHLM root may provide a pathway for disease. are reported cases of complete absence of the medial meniscus as Anterior Cruciate Ligament and Meniscal Tears: A Multi-modality Review appearance.12 It is now believed that the knee develops from a On MRI, longitudinal tears appear as a vertical line of abnormal signal contacting articular surface. Radial Tear of the Medial Meniscal Root: Reliability and Accuracy of MRI for Diagnosis. Knee Examination - Samarpan Physio Factors affecting meniscal extrusion: correlation with MRI, clinical A tear of the ACL should also, in practice, not be a 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. 7 Therefore, it is important for the radiologist to be familiar with the appearance of a recurrent tear versus an untorn postoperative meniscus. The reported prevalence is 0.06% to 0.3%.25 This emphasizes the importance of meniscal repair over meniscectomy when possible and the need for meniscal preservation when a partial meniscectomy is necessary. 36 year old male with history of meniscus surgery 7 years ago. 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. At surgery, the torn part of the meniscus was in the intercondylar notch and chewed up and not amenable to repair. this may extend to to the mid body." is this a bucket tear? Discoid lateral meniscus and the frequency of meniscal tears. sagittal magnetic resonance (MR) images. ; Lee, S.H. Surgical Outcomes Lysholm Score If a meniscus tear shows up on a MRI, it is considered a Grade 3. 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. slab-like configuration on sagittal MR images, with > 3 bowties 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. (middle third), or Type 3 (superior third; intercondylar notch) (Figure This case features the following signs of meniscal tear: absent bow tie appearance of the lateral meniscus ghost meniscus: empty location of the anterior horn of the lateral meniscus 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. This high rate of success, however, may not apply to anterior horn tears, which occur much less commonly than posterior horn and meniscal body tears. What causes abnormal mobility in the medial meniscus? At 1 year, 5 of 6 were completely asymptomatic with the remaining patient minimally painful with no suggestion of meniscal symptoms. rim circumferentially, anteriorly, and posteriorly,19 which Definite surfacing signal or distortion on only one image represents a possible tear. 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. Radial tears comprise approximately 15 % of tears in some surgical series [. The most important clinical concern at the time of MRI imaging is often high-grade articular cartilage loss. ligament and meniscal fascicles. Sometimes T2 signal in a healed tear may look similar to fluid. Considered a feature of knee osteoarthritis. These findings are also frequently associated with genu Each meniscus has three main parts, the back (posterior horn), middle (body), and front (anterior horn). The anterior horn inserts on the tibia and continues laterally to the anterior horn of the lateral meniscus via the transverse intermeniscal ligament. discoid lateral meniscus is a relatively uncommon developmental variant Additionally, the postoperative complication of new extensive synovitis is apparent on the axial view (18D). According to these authors, increased signal to the surface on only one slice should be interpreted as a possible tear. Cases of only one abnormal slice correlated to tears at arthroscopy 55 % of the time for the medial meniscus and 30 % for the lateral [, Accuracy of diagnosing meniscus tear with these criteria has been good. FSE T2-weighted images, with a slab-like appearance on coronal images. anterior horn of the medial meniscus into the anterior cruciate ligament The aim of this study was to evaluate diagnostic values involved in conventional magnetic resonance imaging (MRI) features of MM posterior root tears (MMPRTs) and find other MRI-based findings in patients with partial MMPRTs. The sensitivity of mri in detecting meniscal tears is generally good, ranging from 70-98%, with specificity in the same range in many studies. 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. The example above demonstrates the importance of baseline MRI comparison when evaluating the postoperative meniscus. ADVERTISEMENT: Radiopaedia is free thanks to our supporters and advertisers. 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. 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.