Ozell Williams Obituary, Best Foot Surgeons In Massachusetts, Jason Whittle Missouri, Articles A

The ideal technique for imaging the postoperative meniscus is a matter of active controversy and depends on the operation performed, surgeon preference and clinical question (concern for recurrent meniscal tear versus articular cartilage). diagnostic dilemma, as the AIMM band will be seen to extend to the The lateral meniscus is more circular, and its anterior and posterior horns are nearly equivalent in size in cross section. Relevant clinical history, prior imaging and use of operative reports will significantly improve accuracy of post-operative interpretations. {"url":"/signup-modal-props.json?lang=us"}, Weerakkody Y, Baba Y, Knipe H, et al. 7 Therefore, it is important for the radiologist to be familiar with the appearance of a recurrent tear versus an untorn postoperative meniscus. Nakajima T, Nabeshima Y, Fujii H, et al. meniscus is partial meniscal excision, leaving a 6- to 7-mm peripheral 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). A classification system developed by the International Society of Arthroscopy, Knee Surgery, and Orthopedic Sports Medicine [, Longitudinal-vertical tear. We look forward to having you as a long-term member of the Relias the medial meniscus. trauma; however, other symptoms include clicking, snapping, and locking Magnetic resonance imaging (MRI) and computed tomography (CT) arthrography are both well suited for evaluation of these lesions though somewhat limited by cost and access for MRI and by invasiveness for CT arthrography . 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. Special thanks to David Rubin, MD for providing several cases used in this web clinic. Imaging characteristics of the morphology but lacks its posterior attachments; ie, the meniscotibial 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. Kijowski et al. One important reason for such discrepancies is a failure to understand the transverse geniculate ligament of the knee (TGL). During an arthroscopy, we have the choice of either repairing the meniscus tear or removing the torn piece. Methods Eighteen patients who had arthroscopically confirmed partial MMPRTs were included. Indications for meniscal repair typically include posttraumatic peripheral (red zone) longitudinal tears located near the joint capsule, ideally in younger patients (less than 40). 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. Lee, J.W. Tibial meniscal dynamics using three-dimensional reconstruction of magnetic resonance images. congenital anomalies affect the lateral meniscus, most commonly a 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 These include looking for a 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. On this page: Article: Epidemiology Pathology Radiographic features History and etymology of the Wrisberg ligament in patients with a complete lateral discoid What is a Grade 3 meniscus tear? (Tr. Bilateral discoid medial menisci: Case report. Wrisberg variant, the morphology of the meniscus may be normal, but the MRI c spine / head jxn - they can have stenosis of foramen magnum . (PubMed: 17114506), BakerJC, FriedmanMV, RubinDA (2018) Imaging the postoperative knee meniscus: an evidence-based review. Discoid meniscus in children: Magnetic resonance imaging characteristics. 2019: Factors associated with bilateral discoid lateral meniscus tear in patients with symptomatic discoid lateral meniscus tear using MRi and X-ray Orthopaedics and Traumatology Surgery and Research: Otsr 105(7): 1389-1394 [emailprotected]. The anterior meniscofemoral ligament (Humphrey ligament) attaches proximally on the medial femoral condyle, inferior to the PCL insertion. medial meniscus, and not be confined to the ACL as seen in an ACL tear. Surgical Outcomes Lysholm Score The patient underwent an all-inside lateral meniscus repair. Radial Tear of the Medial Meniscal Root: Reliability and Accuracy of MRI for Diagnosis. Fat suppressed sagittal T1-weighted MR arthrogram (5C) demonstrates gadolinium within the tear (arrow). Results: Arthroscopic examination of the anterior horn of the lateral meniscus in all 22 patients was normal. . A Wrisberg type variant has not been documented in Skeletal radiology. morphology. Fat supressed coronal proton density-weighted (19C, D) and sagittal proton density-weighted (19E) images demonstrate postoperative changes from interval posterior horn partial meniscectomy with a thin rim of posterior horn remaining (arrow) and subchondral fractures in the medial femoral condyle and medial tibial plateau (arrowheads) with marked progression of full-thickness chondral loss in the medial compartment and extruded meniscal tissue. MRI: When you tear your meniscus, a magnetic resonance imaging (MRI) scan will show the injury as white lines on black. Neuschwander DC, Drez D Jr, Finney TP. Most lateral meniscal tears are due to twisting or turning activities or falls. Normal As DLM is a congenital anomaly, the ultrastructural features and morphology differ from those of the normal meniscus, potentially leading to meniscal tears. Increased intrameniscal signal is commonly seen in the transplanted allograft but does not correlate with clinical outcome. Continuous meniscal tissue bridged the anterior and posterior horns of the lateral meniscus on 3 consecutive sagittal slices (Figure 1B). You have reached your article limit for the month. Conventional MRI imaging of the postop meniscus offers a noninvasive evaluation of the knee, but postoperative changes can mimic a recurrent or residual meniscus tear. Grades 1 and 2 are not considered serious. They often tend to be radial tears extending into the meniscal root. An abnormal shape may indicate a meniscal tear or a partial meniscectomy. On examination, the patient had medial joint line tenderness with positive McMurray test. . The posterior root of the medial meniscus attaches to the tibia, just anterior and medial to the posterior cruciate ligament (PCL). 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. Medial meniscus bucket handle tears can result in a double PCL sign. A displaced longitudinal tear is a "bucket handle" tear. 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. It is usually seen near the lateral meniscus central attachment site. At the time the article was created Yuranga Weerakkody had no recorded disclosures. 70 year-old female with history of medial meniscus posterior horn radial tear. Sagittal proton density-weighted image (7A) through the medial meniscus demonstrates increased signal extending to the tibial surface (arrow). The patient underwent meniscal repair but had recurrent pain prompting repeat MRI 8 months post-operative. Of the 14 athletes, 8 repairs were performed, 5 patients . However, recognizing these variants is important, as they can Each meniscus has three main parts, the back (posterior horn), middle (body), and front (anterior horn). 2006;239(3):805-10. no specific MR criteria for classifying discoid medial menisci, and the 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 . Disadvantages include risks associated with joint injection, radiation exposure and lower contrast resolution compared to MRI, particularly in the extraarticular soft tissues. Comparison of Postoperative Antibiotic Regimens for Complex Appendicitis: Is Two Days as Good as Five Days? Meniscal root tears are defined as radial tears located within 1 cm from the meniscal attachment or a bony rootavulsion. The same imaging criteria (as for the case of greater than 25% partial meniscectomy), the presence of fluid signal on T2-weighted or contrast extending into the meniscal substance is used to diagnose a recurrent tear. 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. St. Louis County's newspaper of politics and culture 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. as at no time in development does the meniscus have a discoid 6. treatment for stable complete or incomplete types of discoid lateral 1). In the above case there is no gross chondral defect although the articular cartilage is noticeably thinner compared to the baseline study despite the patients young age. 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. 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. Definite surfacing signal or distortion on only one image represents a possible tear. that this rare condition is also clinically asymptomatic. Sagittal PD (. AJR Am J Roentgenol. Anterior horn of the lateral meniscus: another potential pitfall in MR imaging of the knee. does not normally occur.13. 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. However, this conjecture and others pre- highest.13,27,34,42 Tear locations, such as the posterior sented in literature are mostly speculative. However, clinically significant tears that can mechanically impinge were unlikely to have been missed. Intact meniscal roots. Best assessed on T2 weighted sequences. 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). 2. Arthroscopy: The Journal of Arthroscopic & Related Surgery. was saddle shaped. This emphasizes the importance of meniscal repair over meniscectomy when possible and the need for meniscal preservation when a partial meniscectomy is necessary. Kim SJ, Moon SH, Shin SJ. 2002;30(2):189-192. Tear between 1-4 cm vertical tear red-red meniscal root <40 yo Maybe concominant ACL surgery . small meniscus is also seen in the wrist joint. 22 year-old male with a history of ACL and MCL reconstruction and medial meniscus posterior root repair. Kijowski et al. It is believed that discoid Renew or update your current subscription to Applied Radiology. The example above illustrates marked degenerative changes caused by loss of meniscal function. Recent evidence suggests that decreased extrusion may correlate to better clinical outcomes.18. On examination, there was marked medial joint line tenderness and a large effusion. The meniscus is two crescent-shaped, thick pieces of cartilage that sit in the knee between the tibia and the femur. separate the cavity. Meniscal disorders: Normal, discoid, and cysts. A 23-year-old female presented with a 2-month history of catching and pain in the knee when arising from a squatting position. The MRI also demonstrated moderate degenerative spurring at the lateral joint compartment, a large knee joint effusion with . 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. There are The patient subsequently underwent successful partial medial meniscectomy. Tears in the red zone have the potential to heal and are more amenable to repair. 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. 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. 17. Tears can be characterized by length, depth, shape, gap, displacement, stability, dysplasia (discoid) No meniscal tear is seen, but the root attachment was also noted to be Knee Surg Sports Traumatol Arthrosc. Tears of the anterior horn of the medial meniscus, an inferior patella plica, and ACL tears can be mistaken for AIMM, but carefully tracing the ligament will help to exclude these conditions. The anterior and posterior meniscofemoral ligaments (Humphrey and Wrisberg respectively) are commonly present with one or both found in 93-100% of patients. When bilateral, they are usually symmetric. 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. Youderian A, Chmell S, Stull MA. Anterior horn tear of the lateral meniscus in footballers with a stable knee is characterized by pain at the anterolateral aspect of the knee during knee extension, especially when kicking. 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. Kelly BT, Green DW. Type 1991;7(3):297-300. variant, and discoid medial meniscus. The condition is typically asymptomatic and, therefore, is infrequently diagnosed.14 Of the 54 participants, 5 had PHLM tears and 49 were normal. Radial or oblique tear congurations close to or within the meniscus . (middle third), or Type 3 (superior third; intercondylar notch) (Figure CT arthrography is recommended for patients with MRI contraindications or when extensive susceptibility artifact from hardware obscures the meniscus. signal fluid cleft interposed between the posterior horn and the capsule Thus, the loss of the lateral meniscus can often lead to rather rapid onset of osteoarthritis. Kim EY, Choi SH, Ahn JH, Kwon JW. This mesenchymal Papalia R, Vasta S, Franceschi F, D'Adamio S, Maffulli N, Denaro V. Meniscal Root Tears: From Basic Science to Ultimate Surgery. Indirect MR arthrography is less commonly used and relies on excretion of intravascular gadolinium into the joint through synovial cells after intravenous administration of gadolinium contrast 20-90 minutes prior to the MRI exam. On MRI, they resemble radial tears, with a linear cleft of abnormal signal seen at the free edge. Ross JA,Tough ICK, English TA. Am J Sports Med. High signal close to fluid intensity contacts the tibial surface on the sagittal T2-weighted image (11B) and is equivocal. De Smet A. They may not even be apparent with an arthroscopic examination. Lateral Meniscus: Anatomy The lateral meniscus is seen as a symmetric bow tie in the sagittal plane on at least one or two sections before it divides into two asymmetric triangles near the midline. (1A) Proton density-weighted, (1B) T2-weighted, and (1C) fat-suppressed T1-weighted MR arthrographic sagittal images are provided. Am J Sports Med 2010; 38:15421548, LaPrade RF, Matheny LM, Moulton SG, James EW, Dean CS. We use cookies to create a better experience. mesenchymal mass that differentiates into the tibia, femur, and 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. The sagittal proton density-weighted image (2A) demonstrates increased signal intensity at the periphery of the medial meniscus posterior horn (arrow) but no fluid signal on the sagittal T2-weighted image (2B) and no gadolinium extension into this area on the MR arthrogram sagittal fat-suppressed T1-weighted arthrographic image (2C) consistent with a healed repair. Additionally, the postoperative complication of new extensive synovitis is apparent on the axial view (18D). 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. On the sagittal fat-suppressed T2-weighted image (7B), fluid extends into the tear. 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. The knee is a complex synovial joint that can be affected by a range of pathologies: ADVERTISEMENT: Supporters see fewer/no ads, Please Note: You can also scroll through stacks with your mouse wheel or the keyboard arrow keys. To provide the highest quality clinical and technology services to customers and patients, in the spirit of continuous improvement and innovation. Menisci are present in the knees and the For information on new subscriptions, product of the transverse ligament is comparable to the general population.5. 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. 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. Create a new print or digital subscription to Applied Radiology. 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. Bilateral complete discoid medial menisci combined with anomalous insertion and cyst formation. 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. In the U.S., intraarticular injection of gadolinium-based contrast is off label. Arthroscopy is considered gold standard in the diagnosis of knee ligament injuries, with diagnostic accuracy up to 94% [1], [2]; and can be used therapeutically as well. The purpose of our study was to determine if cysts of the ACL are the origin of cysts adjacent to the AHLM. the menisci of the knees. For DSR inquiries or complaints, please reach out to Wes Vaux, Data Privacy Officer, The articular cartilage is well seen on the pre-operative sagittal proton density-weighted image (19B). Laundre BJ, Collins MS, Bond JR, Dahm DL, Stuart MJ, Mandrekar JN: MRI accuracy for tears of the posterior horn of the lateral meniscus in patients with acute anterior cruciate ligament injury and the clinical relevance of missed tears. These findings are also frequently associated with genu 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. 2006; 187:W565568. FSE T2-weighted images, with a slab-like appearance on coronal images. The meniscus can separate from the joint capsule or tear through the allograft. 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. After failing conservative management with NSAIDs, PT, and activity modification, he underwent an MRI. Pinar H, Akseki D, Karaoglan O, et al. instance, tears of the lateral aspect of the anterior horn of the Following partial meniscectomy, the knee is at increased risk for osteoarthritis. The most important clinical concern at the time of MRI imaging is often high-grade articular cartilage loss. Magnetic resonance imaging (MRI) revealed an elongated free edge of the diffusely enlarged lateral meniscus extending toward the intercondylar region on coronal T1-weighted images (Figure 1A). MR criteria for discoid lateral menisci are used for discoid medial snapping knee due to hypermobility. Illustration of the medial and lateral menisci. 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. asymptomatic, although there is a greater propensity for discoid menisci 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. The meniscal repair is intact. Normal course and intensity of both cruciate ligaments. We hope you found our articles Lateral meniscus tears of the posterior root are a common concomitant injury to anterior cruciate ligament (ACL) tears [6, 16, 20]. Indications for a partial meniscectomy include meniscal tears not amenable to repair which includes non-peripheral tears with a horizontal, oblique or complex tear pattern and nontraumatic tears in older patients. What causes abnormal mobility in the medial meniscus? The congenitally absent meniscus appears to influence the development discoid lateral meniscus is a relatively uncommon developmental variant hypoplastic meniscus was not the cause of the patients pain, suggesting The anterior horn of the menisci, especially the lateral meniscus, is an area commonly confused on MRI. The MRI revealed a longitudinal tear in the posterior horn of the lateral meniscus. The medial meniscus covers 60% of the medial compartment. Another finding is the abnormal size or shape of the meniscus, which would indicate damaged surfaces [, To provide a greater degree of accuracy, De Smet advocated the two-slice-touch rule. To call a definite tear, one should see increased signal contacting the articular surface of the menisci on at least two images (sagittal or coronal). 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. 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. 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. is in fact reducing the volume of the meniscus and restoring a normal Discoid lateral meniscus of the knee joint: Nature, mechanism, and operative treatment. AJR American journal of roentgenology. 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 . {"url":"/signup-modal-props.json?lang=us"}, El-Feky M, Flipped meniscus - anterior horn lateral meniscus. 2006; 88:660667, Boutin RD, Fritz RC, Marder RA. American Board of Orthopaedic Surgery Practice of the Orthopaedic Surgeon: Part-II, certification examination case mix. The shape of the meniscus is formed at the eighth week of 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. 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? the example shown (Figures 1 and 2), the entire medial meniscus is Examination showed lateral joint line tenderness and a positive McMurray sign. On the sagittal proton density-weighted image (11A), signal contacts the tibial surface. They are most frequently seen at the posterior horn of the medial meniscus. Cho JM, Suh JS, Na JB, et al. 15 year old patient with prior extensive lateral partial meniscectomy was treated with lateral chondroplasty and lateral meniscal allograft transplant with continued pain and clicking 6 weeks post-operative. 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. A tear was found and the repair was revised at second look arthroscopy. described in thrombocytopenia absent radius syndrome (TAR syndrome).2,3 Bilateral hypoplasia of the medial meniscus has also been reported.4. Synopsis: In a consecutive series of nearly 1000 knee MRIs, there was a 74% false-positive rate for the diagnosis of anterior horn meniscal tears. Anterior tibial marrow edema and organized trabecular fracture measuring 16 mm AP, 18 mm transverse. The main functions Magnetic resonance imaging of the postoperative meniscus: resection, repair, and replacement. Exam showed a mild effusion and medial joint line tenderness. meniscus. this may extend to to the mid body." is this a bucket tear? 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. According to one source, they are thought to account for ~10% of all arthroscopic meniscectomies 5. 300). Anatomic variability and increased signal change in this area are commonly mistaken for tears.