anterior horn lateral meniscus tear: mri

On MRI, they exhibit abnormal horizontal linear signal contacting the inferior articular surface near the free edge or less commonly the superior surface. 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. Monllau J, Gonzalez G, Puig L, Caceres E. Bilateral hypoplasia of the medial meniscus. Singh K, Helms CA, Jacobs MT, Higgins LD. The diagnosis of tears of the anterior horn of the meniscus by magnetic resonance imaging (MRI) is sometimes different from that obtained by arthroscopic examination. Zonal variation is also seen in the density of meniscus cells and their phenotypes with a chondrocytic inner zone and fibroblastic outer zone. Kelly BT, Green DW. Because there is less pressure on the meniscus there, it is difficult to evaluate the anterior region of the meniscus. Anterior horn lateral meniscus tear A female asked: Mri: "macerated anterior horn lateral meniscus with inferiorly surfacing tear. structure on sagittal images on T1, proton density, and fat-saturated Variations in meniscofemoral ligaments at anatomical study and MR imaging. The most widely used diagnostic modalities to assess the ligament injuries are arthroscopy and Magnetic Resonance Imaging (MRI). 800-688-2421. (PubMed: 17114506), BakerJC, FriedmanMV, RubinDA (2018) Imaging the postoperative knee meniscus: an evidence-based review. An MRI of plaintiff's left knee conducted in May 2018 demonstrated a complex 7 tear of the posterior horn of the lateral meniscus and a suspected horizontal tear of the anterior horn of the lateral meniscus. Comparison of Postoperative Antibiotic Regimens for Complex Appendicitis: Is Two Days as Good as Five Days? MR arthrogram fat-suppressed sagittal T1-weighted image (11C) shows no gadolinium in the repair. no financial relationships to ineligible companies to disclose. Magnetic resonance imaging (MRI) is the most accurate imaging technique in the diagnosis of meniscal lesions and represents a standard tool in knee evaluation. St. Louis County's newspaper of politics and culture Medial meniscus bucket handle tears can result in a double PCL sign. Suprapatellar plica noticed, with no related cartilaginous erosions. 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. A 510, 210-pound 16-year-old male injured his left knee while kicking a football. 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. 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. Kim SJ, Choi CH. 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. meniscal injury. Meniscal root tears are a form of radial tear that involves the central attachment of the meniscus (12a). This scan showed a radial MMT. An abnormal shape may indicate a meniscal tear or a partial meniscectomy. 4. 2. Interested in Group Sales? Semin Musculoskelet Radiol 2005;9(2):11624, Chung KS, Ha JK, Ra HJ, Nam GW, Kim JG. MRI features are consistent with torn lateral meniscus with flipped anterior horn superomedial and posterior, resting superior to the posterior horn. least common is complete congenital absence of the menisci. 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. Br Med Bull. . A tear was found and the repair was revised at second look arthroscopy. An intact meniscal repair was confirmed at second look arthroscopy. Anterior lateral cysts extended . 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. Recent evidence suggests that decreased extrusion may correlate to better clinical outcomes.18. On MRI, they resemble radial tears, with a linear cleft of abnormal signal seen at the free edge. Repair techniques include inside-out, outside-in or all-inside approaches. Twenty-one had ACL tears; all those with an PHLM tear had an ACL tear. 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. AJR Am J Roentgenol 211(3):519527, De Smet AA. 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 from AIMM. Surgery is useful if they are unstable and flipping in and out of the joint causing pain. 7.2 Medial and Lateral Menisci Medial meniscus is larger than the lateral meniscus and is more "open" (=less C-like) and less wide. He presented after a few months with symptoms of instability. Radial Tear of the Medial Meniscal Root: Reliability and Accuracy of MRI for Diagnosis. According to one source, they are thought to account for ~10% of all arthroscopic meniscectomies 5. Type 1 is most common, and type It splits into two bands at the PCL, named Humphry(anterior to the PCL) and Wrisberg (posterior to the PCL). The MRI revealed a vertical flap (oblique) tear of the medial meniscus. Arthroscopy: The Journal of Arthroscopic & Related Surgery. Intensity of signal contacting meniscal surface in recurrent tears on MR arthrography compared with that of contrast material. Best assessed on T2 weighted sequences. For root tears in general, sagittal imaging may demonstrate a meniscal ghost sign. 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. Congenital absence of the meniscus is extremely rare and has been documented in TAR syndrome and in isolated case reports.2,3 2006; 88:660667, Boutin RD, Fritz RC, Marder RA. of the anterior horn of the medial meniscus, an inferior patella plica, high fibula head and a widened lateral joint space.20 Several The anomalous insertion The trusted source for healthcare information and CONTINUING EDUCATION. Radiographic knee dimensions in discoid lateral meniscus: Comparison with normal control. (middle third), or Type 3 (superior third; intercondylar notch) (Figure AJR Am J Roentgenol. Normal course and intensity of both cruciate ligaments. 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. Lateral meniscus extrusion was present in six (23%) of 26 LMRTs and five (2.2%) of 231 patients with normal meniscus roots ( P < .001). Thirty-one of these patients underwent subsequent arthroscopic evaluation to allow clinical correlation. Thompson WO, Thaete FL, Fu FH, Dye SF. Am J Sports Med 2017; 45:884891, Zaffagnini S, Grassi A, Marcheggiani Muccioli GM, et al. Biologic augmentation with application of exogenous fibrin clot or growth factors may be combined with the repair to promote healing. variant, and discoid medial meniscus. Both horns of the medial meniscus are triangular with sharp points. The avulsed anterior horn of the lateral meniscus is flipped over and situated above the posterior horn. be misinterpreted for more significant pathology on MRI. Atypically thick and high location in this case were attributed to an anterior cruciate ligament tear To assess the prevalence of meniscal extrusion and its . Posterior meniscal root repairs: outcomes of an anatomic transtibial pull-out technique. Is sport activity possible after arthroscopic meniscal allograft transplantation? 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. 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. Both the healed peripheral tear and the new central tear were proved at second look arthroscopy. 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. of the meniscus. discoid lateral meniscus is a relatively uncommon developmental variant 2012;20(10):2098-103. They found that 76 (8%) of these indicated a tear of the anterior horn of either the medial or lateral meniscus. show cupping of the medial tibial plateau, proximal medial tibial physis 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. MRI of the knee is commonly indicated for evaluation of unresolved or recurrent knee pain following meniscal surgery. Knee Surg Sports Traumatol Arthrosc. A displaced longitudinal tear is a "bucket handle" tear. Sagittal T2-weighted image (10B) reveals no fluid at the repair site. Normal Following meniscal allograft transplantation (Figure 17), complications occur in up to 21% of procedures, including allograft failure and progressive cartilage loss.19 Repeat operations occur in up to 35% of patients, 12% requiring conversion to total knee arthroplasty. 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. 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. menisci develop from this mesenchymal tissue in a site where this tissue AJR Am J Roentgenol. There are The lateral meniscus is one of two fibrocartilaginous menisci of the knee. Report anterior horn of the medial meniscus into the anterior cruciate ligament We use cookies to create a better experience. Youderian A, Chmell S, Stull MA. Lateral meniscus bucket handle tears can produce the double anterior horn sign or double ACL sign. has shown that 41% of patients with a surgically confirmed torn post-operative meniscus had signal intensity within the meniscus extending into the articular surface which was lower than the signal intensity of gadolinium contrast.14 Like the presence of a line of intermediate T2 signal extending into the articular surface on conventional MRI, diagnosis of a torn post-operative meniscus on MRI arthrography is challenging when the intra-meniscal signal intensity is not as bright as gadolinium contrast. reported.4. joint: Morphologic changes and their potential role in childhood At surgery, the torn part of the meniscus was in the intercondylar notch and chewed up and not amenable to repair. They often tend to be radial tears extending into the meniscal root. The medial meniscus covers 60% of the medial compartment. Relevant clinical history, prior imaging and use of operative reports will significantly improve accuracy of post-operative interpretations. Become a Gold Supporter and see no third-party ads. Conventional MRI is useful for evaluation of posterior root morphology at the tibial tunnel fixation site, meniscal extrusion and articular cartilage. Longitudinal lateral meniscus tear status post repair (arrow). 17. 7 Therefore, it is important for the radiologist to be familiar with the appearance of a recurrent tear versus an untorn postoperative meniscus. Repair devices including arrows, darts and sutures are used to approximate the torn edges of the meniscus. Kijowski et al. Tolo VT. Congenital absence of the menisci and cruciate ligaments of the knee: A case report. This injury is biomechanically comparable to a total meniscectomy, leading to compromised hoop stressesresulting in decreased tibiofemoral contact area and increased contact pressures in the involved compartment.These changes are detrimental to the articular cartilage and . Considered a feature of knee osteoarthritis. medial meniscus are extremely uncommon and should not be a diagnostic Methods Eighteen patients who had arthroscopically confirmed partial MMPRTs were included. If a meniscus tear shows up on a MRI, it is considered a Grade 3. 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 . If missing on MR images, a posterior root tear is present. 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 ligament of Humphrey inserted on average 0.9 consecutive images lateral to the PCL without an PHLM tear and 4.7 with an PHLM tear; the ligament of Wrisberg inserted on average 3.0 consecutive images without an PHLM tear and 4.5 with an PHLM tear . Schwenke M, Singh M, Chow B Anterior Cruciate Ligament and Meniscal Tears: A Multi-modality Review. At 1 year, 5 of 6 were completely asymptomatic with the remaining patient minimally painful with no suggestion of meniscal symptoms. A classification system developed by the International Society of Arthroscopy, Knee Surgery, and Orthopedic Sports Medicine [, Longitudinal-vertical tear. is affected. diminutive (1 mm) with no increased signal to suggest root attachment The Wrisberg variant may present with a the medial meniscus. Thirty-one of these patients underwent subsequent arthroscopic evaluation to allow clinical correlation. For DSR inquiries or complaints, please reach out to Wes Vaux, Data Privacy Officer, 2005; 234:5361. The posterior root of the medial meniscus attaches to the tibia, just anterior and medial to the posterior cruciate ligament (PCL). In cases like this, MR arthrography is quite helpful. Discoid lateral meniscus. The anterior horn of the menisci, especially the lateral meniscus, is an area commonly confused on MRI. Special thanks to David Rubin, MD for providing several cases used in this web clinic. The self-reported complication rate for partial meniscectomy is 2.8% and meniscus repair is 7.6%. RESULTS. 3: The Wrisberg variant, where the meniscus may have a normal Kim SJ, Moon SH, Shin SJ. Tears discoid lateral meniscus, including a propensity for tears to occur and Each meniscus has three main parts, the back (posterior horn), middle (body), and front (anterior horn). For information on new subscriptions, product Grades 1 and 2 are not considered serious. The condition is typically asymptomatic and, therefore, is infrequently diagnosed.14 3 is least common. insertion of the medial meniscus (AIMM) has been described, and it is of the menisci can be summarized as providing: Clark and Ogden studied the natural development of the menisci in the It is usually seen near the lateral meniscus central attachment site. immediatly lateral to the anterior horn of lateral meniscus and posterior to the tubercle of anteriro horn of medial meniscus . Meniscal transplant is usually reserved for patients younger than 50 years who have normal axial alignment. Stay up to date with the latest in Practical Medical Imaging and Management with Applied Radiology. Most horizontal tears extend to the inferior articular surface. ADVERTISEMENT: Radiopaedia is free thanks to our supporters and advertisers. No meniscal tear is seen, but the root attachment was also noted to be An intact meniscal repair was confirmed at second look arthroscopy. to tear. The meniscal repair is intact. are reported cases of complete absence of the medial meniscus as Pre-operative fat supressed coronal proton density-weighted image (19A) demonstates a posterior root radial tear (arrow). American Board of Orthopaedic Surgery Practice of the Orthopaedic Surgeon: Part-II, certification examination case mix. Pullout fixation of posterior medial meniscus root tears: correlation between meniscus extrusion and midterm clinical results. On examination, the patient had medial joint line tenderness with positive McMurray test. Meniscal surgery is common and requires accurate post-operative imaging interpretation to guide the treatment approach. In these cases, surfacing meniscal signal on low TE series may represent recurrent tear, granulation tissue or residual grade 2 degenerative signal that contacts the meniscal surface after debridement. Kaplan EB. ligaments and menisci causing severe knee dysplasia in TAR syndrome. Description. (Figure 1). History of medial meniscus posterior horn partial meniscectomy. Am J Sports Med. 2002; 222:421429, Ciliz D, Ciliz A, Elverici E, Sakman B, Yuksel E, Akbulut O. A Presentation - Middle-older aged individuals, non-traumatic, progressive onset of pain. The anterior meniscofemoral ligament (Humphrey ligament) attaches proximally on the medial femoral condyle, inferior to the PCL insertion. pretzels dipped in sour cream. Radiographs are usually not diagnostic, but they may show a This has also been described as grade 2 signal [, Sagittal fat-suppressed T2 image of a 14-year-old patient showing a grade 2 signal in the posterior horn of the medial meniscus (PHMM). an adult), and approximately twice the size of the anterior horn on 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. 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. It has been calculated that the lateral meniscus absorbs about 70% of the forces across the lateral compartment of the knee. 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. Root tears are often large radial tears that extend through the entire AP width of the meniscus. of the transverse ligament is comparable to the general population.5. Radiology. Unable to process the form. 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. A previous study by De Smet et al. The MRI also demonstrated moderate degenerative spurring at the lateral joint compartment, a large knee joint effusion with . Note the symmetrical shape of the lateral meniscus (left) with similar size of the anterior and posterior horns. gestation, about the time when the knee joint is fully formed.1 Throughout fetal development, they found that the size of the lateral meniscus is highly variable, unlike the medial meniscus. 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 [. Generally, The meniscus may also become hypertrophic. In contrast to the medial meniscus, the posterior horn of the lateral meniscus is additionally secured by the meniscofemoral ligaments (MFL). Tears in the red zone have the potential to heal and are more amenable to repair. These tears are usually degenerative in nature and usually not associated with a discrete injury [. Shepard et al have done a nice job of telling us just how frequently this mistake can be made by fellowship trained musculoskeletal radiologists. Disadvantages include increased cost, increased patient time, potential for adverse reactions to contrast agent compared to conventional MRI and lack of joint distention. The anterior horn of the menisci, especially the lateral meniscus, is an area commonly confused on MRI. Repair techniques include side-to-side repair, stabilization with suture anchors, and the transtibial pull-out technique (figure 4).12. MR criteria for discoid lateral menisci are used for discoid medial The post arthrogram view (13B) reveals gadolinium within the repair site. 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. Arthroscopy revealed a horizontal tear of PHMM, and a partial medial meniscectomy was performed. Extrusion is commonly seen following root repair. 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. Kocher MS, Klingele K, Rassman SO. Copy. Of the 54 participants, 5 had PHLM tears and 49 were normal. Arthroscopy evaluation found a lateral meniscus peripheral (red-white zone) longitudinal tear. However, this conjecture and others pre- highest.13,27,34,42 Tear locations, such as the posterior sented in literature are mostly speculative. The reported prevalence is 0.06% to 0.3%.25 meniscus are not uncommon; they include an anomalous insertion of the runs from the anterior horn of the medial meniscus to either the ACL or Exam showed a mild effusion and medial joint line tenderness. Clin Orthop Relat Res 2013; 471: pp. Check for errors and try again. 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). Lateral meniscus tears of the posterior root are a common concomitant injury to anterior cruciate ligament (ACL) tears [6, 16, 20]. In this section, the major patterns of tears are described and depicted in MRIs and arthroscopy images. menisci occurs. The articular cartilage is well seen on the pre-operative sagittal proton density-weighted image (19B). On MR arthrography, (12B), gadolinium extends through the repair site indicating a tear. Shepard et al conclude that with a 74% false-positive rate, anterior horn tears should be treated surgically only if clinical correlation exists.