A Tolo VT. Congenital absence of the menisci and cruciate ligaments of the knee: A case report. 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. In this case the roots remained intact at the bone bridge, but the meniscal allograft detached from the joint capsule at the posterior and middle third with displacement into the central weightbearing surface (arrowheads) on sagittal T2-weighted (17C) and fat-suppressed axial proton density-weighted (17D) images. MRI Gallery - MRI Knee - Meniscal tears - Radiology Masterclass Problems encountered in a discoid medial meniscus are the same as a They maintain a relatively constant distance from the periphery of the meniscus [. Ross JA,Tough ICK, English TA. We hope you found our articles Posteroinferior displacement of the meniscal tissue (arrowheads) is also diagnostic of recurrent tear. Longitudinal lateral meniscus tear status post repair (arrow). Renew or update your current subscription to Applied Radiology. 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 . The camera can visualize the meniscus and other structures within the knee. Factors affecting meniscal extrusion: correlation with MRI, clinical Diagnostic accuracy of MRI knee in reference to - ScienceDirect Anatomic variability and increased signal change in this area are commonly mistaken for tears. Vertical flap (oblique, flap, parrots beak) tears are unstable tears and occur in younger patients. Pseudotear Sign of the Anterior Horn of the Meniscus The patient had a recent new injury with increased pain. Type 1 is most common, and type 2a, 2b, 2c). If a meniscus tear shows up on a MRI, it is considered a Grade 3. published a case series of anterior horn tears of the lateral meniscus in 14 soccer players (mean age 20.2 years). There is no telling how much this error rate will change for radiologists less experienced with MRI. 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. 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. Nakajima T, Nabeshima Y, Fujii H, et al. Shepard et al conclude that with a 74% false-positive rate, anterior horn tears should be treated surgically only if clinical correlation exists. 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 . Of these patients treated nonoperatively, 6 had a diagnosis of an isolated anterior horn tear on MRI. Dickhaut SC, DeLee JC. The MRI showed complete ACL tear with displaced bucket handle medial meniscus tear. 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. 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. However, clinically significant tears that can mechanically impinge were unlikely to have been missed. MR imaging evaluation of the postoperative knee. 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. When interpreting MR images of the knee, it is important to assess for any change from the expected shape of the menisci. 3 is least common. 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. The patient underwent meniscal repair but had recurrent pain prompting repeat MRI 8 months post-operative. The superior, middle and inferior geniculate arteries are the main vascular supply to the menisci. Download Musculoskeletal MRI by Nancy Major, Mark Anderson congenital anomalies affect the lateral meniscus, most commonly a 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. Clark CR, Ogden JA. in 19916. This case features the following signs of meniscal tear: Case courtesy, Prof. Dr. Khaled Matrawy, Professor of radiology, Alexandria university, Egypt. discoid meniscus, although discoid medial menisci can occur much less 70 year-old female with history of medial meniscus posterior horn radial tear. Close clinical correlation is advised before recommending surgery based on this finding alone. 3. They often tend to be radial tears extending into the meniscal root. This article focuses on Become a Gold Supporter and see no third-party ads. De Smet A. RESULTS. 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. 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. joint, and they also protect the hyaline cartilage. The shape of the meniscus is formed at the eighth week of The purpose of our study was to determine if cysts of the ACL are the origin of cysts adjacent to the AHLM. They often tend to be radial tears extending into the meniscal root. Discoid lateral meniscus: importance, diagnosis, and treatment AJR Am J Roentgenol 211(3):519527, De Smet AA. Samoto N, Kozuma M, Tokuhisa T, Kobayashi K. Diagnosis of discoid lateral meniscus of the knee on MR imaging. 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. Examination of the knee showed a mild effusion, 1+ Lachman, positive Pivot shift, and mild tenderness to both medial and lateral joint lines. are reported cases of complete absence of the medial meniscus as It can be divided into five segments: anterior horn, anterior, middle and posterior segments, and posterior horn. is affected. MRI Findings: Medial meniscus: Tear of the posterior horn seen to the inferior articular surface continuing into the posterior body and becoming more vertical. Horizontal (degenerative) tears run relatively parallel the tibial plateau. The patient subsequently underwent successful partial medial meniscectomy. 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. The patient underwent an all-inside lateral meniscus repair. {"url":"/signup-modal-props.json?lang=us"}, Weerakkody Y, Baba Y, Knipe H, et al. 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. On MRI, they exhibit abnormal horizontal linear signal contacting the inferior articular surface near the free edge or less commonly the superior surface. menisci (Figure 8). Pagnani M, Cooper D, Warren R. Extrusion of the Medial Meniscus. (middle third), or Type 3 (superior third; intercondylar notch) (Figure Exam showed a mild effusion and medial joint line tenderness. How I Diagnose Meniscal Tears on Knee MRI : American Journal of A meta-analysis of 44 trials. least common is complete congenital absence of the menisci. 2006; 187:W565568. morphology. Among these 26 studies of an LMRT . Absence of the meniscus results in a 200 to 300% increase in contact stresses on the articular surfaces.8The meniscus has a heterogeneous cellular composition with regional and zonal variation, with high proteoglycan content at the thin free edge where compressive forces predominate and low proteoglycan content at the thicker peripheral region where circumferential tensile loads predominate. Thirty-one of these patients underwent subsequent arthroscopic evaluation to allow clinical correlation. 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 [. Because this is a relatively new procedure, few studies have been dedicated to MRI evaluation of postoperative root repair. Type 1: A complete slab of meniscal tissue with complete tibial coverage. The MRI revealed a vertical flap (oblique) tear of the medial meniscus. Meniscal root tear | Radiology Reference Article - Radiopaedia Findings indicate an intact meniscus following partial meniscectomy with normal intrameniscal signal. 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). Clin Orthop Relat Res 2012; 470: pp. The symptoms Intensity of signal contacting meniscal surface in recurrent tears on MR arthrography compared with that of contrast material. ADVERTISEMENT: Supporters see fewer/no ads. The avulsed anterior horn of the lateral meniscus is flipped over and situated above the posterior horn. 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 . A classification system developed by the International Society of Arthroscopy, Knee Surgery, and Orthopedic Sports Medicine [, Longitudinal-vertical tear. What is a Grade 3 meniscus tear? Normal Grades 1 and 2 are not considered serious. Figure 8: Medial oblique menisco-meniscal . Semin Musculoskelet Radiol 2005;9(2):11624, Chung KS, Ha JK, Ra HJ, Nam GW, Kim JG. These features constitute O'Donoghue unhappy triad. They divide the meniscus into superior and inferior halves (Fig. The medial meniscus covers 60% of the medial compartment. 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. Unable to process the form. Knee Examination - Samarpan Physio slab-like configuration on sagittal MR images, with > 3 bowties mobility, and a giving-way sensation.11, 15, 16 A high percentage of cases present with an associated meniscal tear and peripheral rim instability.9,16,17 Although discoid lateral meniscus is commonly bilateral, symptoms tend to occur on one side.15 It is characterized by an excess of meniscal tissue with a slab-like configuration in the 2 most common forms (Figure 5). The anomalous insertion The anterior root of the lateral meniscus attaches to the tibia, just lateral to the midline and posterior to fibers of the anterior cruciate ligament (ACL). Coronal extrusion of the lateral meniscus does not increase after hypermobility. Rao PS, Rao SK, Paul R. Clinical, radiologic, and arthroscopic assessment of discoid lateral meniscus. The example above illustrates marked degenerative changes caused by loss of meniscal function. Which meniscus is more likely to tear? Bucket Handle Tear of Lateral Meniscus on MRI - A Case Report Also, the inferior patella plica inserts on the incomplete breakdown of the central meniscus, but this is now disputed, Flipped meniscus - anterior horn lateral meniscus | Radiology Case Shepard and colleagues at UCLA specifically analyzed this by reviewing 947 consecutive MRIs. 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. 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. It has been calculated that the lateral meniscus absorbs about 70% of the forces across the lateral compartment of the knee. MR of the knee: the significance of high signal in the meniscus that 17. Monllau J, Gonzalez G, Puig L, Caceres E. Bilateral hypoplasia of the medial meniscus. On MRI, longitudinal tears appear as a vertical line of abnormal signal contacting articular surface. A tear was found and the repair was revised at second look arthroscopy. . Stay up to date with the latest in Practical Medical Imaging and Management with Applied Radiology. The posterior root lies anterior to the posterior cruciate ligament. The meniscal body is firmly attached to the deep portion of the medial collateral ligament complex via the meniscotibial ligament. Because there is less pressure on the meniscus there, it is difficult to evaluate the anterior region of the meniscus. Best assessed on T2 weighted sequences. Comparison of Medial and Lateral Meniscus Root Tears - PLOS The patient failed conservative management of aspiration and cortisone injection. Get unlimited access to our full publication and article library. What is anterior horn of meniscus? - KnowledgeBurrow.com The congenitally absent meniscus appears to influence the development Rohren EM, Kosarek FJ, Helms CA. Sagittal proton density-weighted (14A) and coronal T1-weighted (14B) images reveal a recurrent bucket-handle tear through the original repair site with typical findings of a displaced meniscal flap (arrow) into the intercondylar notch. Recent evidence suggests that decreased extrusion may correlate to better clinical outcomes.18. Volunteerism and Sports Medicine: Where do We Stand? measurements of the posterior horn of the medial meniscus may vary, but immediatly lateral to the anterior horn of lateral meniscus and posterior to the tubercle of anteriro horn of medial meniscus . 2012;199(3):481-99. Intact meniscal roots. Unable to process the form. Meniscal tears are common and often associated with knee pain. Radiographs may Thompson WO, Thaete FL, Fu FH, Dye SF. variant, and discoid medial meniscus. Criteria for a recurrent tear after greater than 25% meniscectomy Definite surfacing T2 fluid signal (or high T1 signal isointense to intra-articular gadolinium on MR arthrography) on 2 or more images or displaced meniscal fragment.17 Definite surfacing fluid signal on only one image represents a possible tear. show cupping of the medial tibial plateau, proximal medial tibial physis While they can arise from a number of mechanisms, root tears are generally thought to be chronic 5. We use cookies to create a better experience. 1991;7(3):297-300. of the distal femur and proximal tibia, and in the case report of Lateral meniscus bucket handle tears can produce the double anterior horn sign or double ACL sign.