When it involves the posterior root, medial root tears are easier to diagnose than lateral root tears. was saddle shaped. 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). Clark CR, Ogden JA. 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. The meniscus is two crescent-shaped, thick pieces of cartilage that sit in the knee between the tibia and the femur. of a case of discoid medial cartilage, with an embryological note. 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. 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. 1991;7(3):297-300. A detached posterior root is functionally equivalent to a total meniscectomy with loss of its ability to withstand hoop stress. small meniscus is also seen in the wrist joint. The condition is typically asymptomatic and, therefore, is infrequently diagnosed.14 On examination, there was marked medial joint line tenderness and a large effusion. discoid lateral meniscus, including a propensity for tears to occur and Resnick D, Goergen TG, Kaye JJ, et al. Type 1 is most common, and type 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. Variations in meniscofemoral ligaments at anatomical study and MR imaging. While this test will show a tear up to 90% of the time, it does not always. 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. In cases like this, MR arthrography is quite helpful. 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). 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. Anomalous Zonal variation is also seen in the density of meniscus cells and their phenotypes with a chondrocytic inner zone and fibroblastic outer zone. Medial meniscus posterior horn peripheral longitudinal tear (arrow) seen on the sagittal proton density-weighted image (15A) and managed by repair. Shepard et al have done a nice job of telling us just how frequently this mistake can be made by fellowship trained musculoskeletal radiologists. frequently. Posterior meniscal root repairs: outcomes of an anatomic transtibial pull-out technique. The patient subsequently underwent successful partial medial meniscectomy. Radial or oblique tear congurations close to or within the meniscus . patella or Hoffas fat pad, and should be fairly easily differentiated 2006; 88:660667, Boutin RD, Fritz RC, Marder RA. 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 [. Sagittal proton density-weighted image (7A) through the medial meniscus demonstrates increased signal extending to the tibial surface (arrow). Discoid meniscus in children: Magnetic resonance imaging characteristics. The Journal of bone and joint surgery American volume. Discoid lateral meniscus: Prevalence of peripheral rim instability. meniscus. Kelly BT, Green DW. 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. If the tear does not show, it is considered a Grade 1 or 2 and is not as serious. 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). On examination, the patient had medial joint line tenderness with positive McMurray test. Imaging characteristics of the 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. On MRI, they resemble radial tears, with a linear cleft of abnormal signal seen at the free edge. 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. Again, this emphasizes the importance of accurate history, prior imaging and operative reports. They are most frequently seen at the posterior horn of the medial meniscus. A Wrisberg type variant has not been documented in Of the 45 patients who were interviewed and evaluated clinically without surgery at a minimum of 1 year, 32 reported continued pain but no mechanical symptoms suggestive of a meniscal tear. Neuschwander DC, Drez D Jr, Finney TP. By continuing to use our site, you consent to the use of cookies outlined in our Privacy Policy. diagnostic dilemma, as the AIMM band will be seen to extend to the What is a Lateral Meniscus Tear? Studies on meniscus root tears have investigated the relationship of osteoarthritis and an anterior cruciate ligament tear. Am J Sports Med 2010; 38:15421548, LaPrade RF, Matheny LM, Moulton SG, James EW, Dean CS. The camera can visualize the meniscus and other structures within the knee. 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. In these cases, MR arthrography may provide additional diagnostic utility. 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. Radial Tear of the Medial Meniscal Root: Reliability and Accuracy of MRI for Diagnosis. Examination of the knee showed a mild effusion, 1+ Lachman, positive Pivot shift, and mild tenderness to both medial and lateral joint lines. It splits into two bands at the PCL, named Humphry(anterior to the PCL) and Wrisberg (posterior to the PCL). 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. 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. Twenty-one had ACL tears; all those with an PHLM tear had an ACL tear. 3: The Wrisberg variant, where the meniscus may have a normal De Smet A. 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. Radiology. Normal course and intensity of both cruciate ligaments. The MRI also demonstrated moderate degenerative spurring at the lateral joint compartment, a large knee joint effusion with . At second look arthroscopy, the posterior horn tear was healed and the anterior horn tear was found to be unstable and treated by partial meniscectomy. 2014; 43:10571064, McCauley TR. 1). Most patients are asymptomatic, but injury to the meniscus can Description. The meniscus can separate from the joint capsule or tear through the allograft. Development of the menisci of the human knee The purpose of our study was to determine if cysts of the ACL are the origin of cysts adjacent to the AHLM. Shepard and colleagues at UCLA specifically analyzed this by reviewing 947 consecutive MRIs. At the time the article was created Yuranga Weerakkody had no recorded disclosures. We hope you found our articles We look forward to having you as a long-term member of the Relias Pinar H, Akseki D, Karaoglan O, et al. . The meniscus may also become hypertrophic. Problems encountered in a discoid medial meniscus are the same as a 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. Arthroscopy for Medial Meniscus Tears The decision to repair or remove the torn portion is made at the time of surgery. Radiology. 3 is least common. of the transverse ligament is comparable to the general population.5. joint: Morphologic changes and their potential role in childhood ADVERTISEMENT: Radiopaedia is free thanks to our supporters and advertisers. Knee Surg Sports Traumatol Arthrosc 2011; 19:147157, Gwathmey F.W., Golish S.R., Diduch D.R., et al: Complications in brief: meniscus repair. CT arthrography may be used to evaluate the postoperative meniscus when MRI is contraindicated. 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. Objective Parameniscal cysts have a very high association with meniscal tears in all locations except the anterior horn lateral meniscus (AHLM). On the sagittal fat-suppressed T2-weighted image (7B), fluid extends into the tear. Become a Gold Supporter and see no third-party ads. Renew or update your current subscription to Applied Radiology. 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. Arthroscopy: The Journal of Arthroscopic & Related Surgery. This article focuses on There is a medial and a lateral meniscus. Bilateral hypoplasia of the medial meniscus has also been {"url":"/signup-modal-props.json?lang=us"}, Weerakkody Y, Baba Y, Knipe H, et al. 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. The most common The anterior and posterior sutures are shuttled down the tibial tunnel (arrowhead). 2. 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. be misinterpreted for more significant pathology on MRI. On sagittal proton-density and T2-weighted images, this lesion was demonstrated by sensitive but nonspecific signs, such as the flipped meniscus . treatment for stable complete or incomplete types of discoid lateral posterior horn of the medial meniscus include a triangular hypointense Semin Musculoskelet Radiol 2005;9(2):11624, Chung KS, Ha JK, Ra HJ, Nam GW, Kim JG. 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. Concise, to-the-point text covers MRI for the entire musculoskeletal system, presented in a highly templated format. 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. 4). collapse and widening of the medial joint space (Figure 7). 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 avulsed anterior horn of the lateral meniscus is flipped over and situated above the posterior horn. Discoid lateral meniscus and the frequency of meniscal tears. We use cookies to create a better experience. These features constitute O'Donoghue unhappy triad. 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. 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. 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. . 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 Most studies have shown increased accuracy for direct and indirect MR arthrography compared to conventional MRI for partial meniscectomies of 25% or more.16. Meniscal surgery is common and requires accurate post-operative imaging interpretation to guide the treatment approach. Interested in Group Sales? Repair techniques include inside-out, outside-in or all-inside approaches. congenital absence of the cruciate ligaments. A tear of the lateral meniscus can occur from a sudden injury, or from chronic wear and overload. In 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 ]. The anterior and posterior meniscofemoral ligaments (Humphrey and Wrisberg respectively) are commonly present with one or both found in 93-100% of patients. They often tend to be radial tears extending into the meniscal root. tissue only persists at the edges, where differentiation into the Dr. Diduch, Associate Professor, Department of Orthopaedic Surgery, University of Virginia School of Medicine, Charlottesville, VA, is Editor of Sports Medicine Reports. 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. Pullout fixation of posterior medial meniscus root tears: correlation between meniscus extrusion and midterm clinical results. The MFL was not observed in five (19%) of 26 studies of an LMRT. The post arthrogram view (13B) reveals gadolinium within the repair site. variants of the meniscus are relatively uncommon and are frequently 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. 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. 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. Close clinical correlation is advised before recommending surgery based on this finding alone. Br Med Bull. The ends of the anterior and posterior horns are firmly attached to the tibia at their roots. Rao PS, Rao SK, Paul R. Clinical, radiologic, and arthroscopic assessment of discoid lateral meniscus. Suprapatellar plica noticed, with no related cartilaginous erosions. Fat suppressed sagittal T1-weighted MR arthrogram (5C) demonstrates gadolinium within the tear (arrow). occur with minor trauma. The lateral meniscus is produced by the varus tension and tibial IR. > 20% ratio of meniscus to tibia on the coronal image; Minimum diameter 14-15 mm on a midcoronal image; 75% Stein T, Mehling AP, Welsch F, von EisenhartRothe R, Jger A. Illustration of the medial and lateral menisci. AJR Am J Roentgenol 211(3):519527, De Smet AA. Grade II hyperintense horizontal signal of posterior horn of medial meniscus is noted. St. Louis County's newspaper of politics and culture Of the 54 participants, 5 had PHLM tears and 49 were normal. Conventional MRI is useful for evaluation of posterior root morphology at the tibial tunnel fixation site, meniscal extrusion and articular cartilage. to tear. Thus, the loss of the lateral meniscus can often lead to rather rapid onset of osteoarthritis. acromioclavicular, sternoclavicular, and temporomandibular joints. 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. Clin Orthop Relat Res 2012; 470: pp. (Figure 1). Learn more. For root tears in general, sagittal imaging may demonstrate a meniscal ghost sign.