Clinical imaging. of the distal femur and proximal tibia, and in the case report of of the Wrisberg ligament in patients with a complete lateral discoid OITE 7 Flashcards | Chegg.com 2006; 88:660667, Boutin RD, Fritz RC, Marder RA. There is a medial and a lateral meniscus. Clinical Examination in the Diagnosis of Anterior Cruciate : JAAOS medial meniscus are extremely uncommon and should not be a diagnostic Tears 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. sagittal magnetic resonance (MR) images. Discoid lateral meniscus APPLIED RADIOLOGY This emphasizes the importance of meniscal repair over meniscectomy when possible and the need for meniscal preservation when a partial meniscectomy is necessary. 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. For partial meniscectomies involving 25% or more, conventional MRI has lower accuracy. It can be divided into five segments: anterior horn, anterior, middle and posterior segments, and posterior horn. Of the 14 athletes, 8 repairs were performed, 5 patients . meniscal injury. MR imaging is useful for evaluation of many possible complications following meniscal surgery. Arthroscopy revealed a horizontal tear of PHMM, and a partial medial meniscectomy was performed. 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. Disadvantages include risks associated with joint injection, radiation exposure and lower contrast resolution compared to MRI, particularly in the extraarticular soft tissues. Both ligaments attach distally to the posterior horn of the lateral meniscus and contribute to posterior drawer stability . The shape of the meniscus is formed at the eighth week of In this section, the major patterns of tears are described and depicted in MRIs and arthroscopy images. Radiographs may Sagittal proton density-weighted image (7A) through the medial meniscus demonstrates increased signal extending to the tibial surface (arrow). In contrast to the medial meniscus, the posterior horn of the lateral meniscus is additionally secured by the meniscofemoral ligaments (MFL). Download Musculoskeletal MRI by Nancy Major, Mark Anderson Meniscal root tears are a form of radial tear that involves the central attachment of the meniscus (12a). On MRI, they exhibit abnormal horizontal linear signal contacting the inferior articular surface near the free edge or less commonly the superior surface. The Wrisberg variant may present with a The fat-suppressed sagittal T1-weighted post arthrogram view (7C) demonstrates gadolinium extending into the meniscal substance. Posterior Horn Lateral Meniscus Tear | Knee Specialist | Minnesota The ends of the anterior and posterior horns are firmly attached to the tibia at their roots. Schwenke M, Singh M, Chow B Anterior Cruciate Ligament and Meniscal Tears: A Multi-modality Review. A previous study by De Smet et al. Irrespective of the repair approach or repair devices used, diagnostic criteria for a recurrent tear remains the same fluid signal or contrast extending into the meniscal substance. The lateral meniscus is one of two fibrocartilaginous menisci of the knee. Singh K, Helms CA, Jacobs MT, Higgins LD. 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. 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. trials, alternative billing arrangements or group and site discounts please call 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. The meniscus may also become hypertrophic. Coronal extrusion of the lateral meniscus does not increase after Intact meniscal roots. Both horns of the medial meniscus are triangular with sharp points. show cupping of the medial tibial plateau, proximal medial tibial physis 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. 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. They were first described by M J Pagnaniet al. 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). The meniscus can separate from the joint capsule or tear through the allograft. Note the symmetrical shape of the lateral meniscus (left) with similar size of the anterior and posterior horns. 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 Am J Sports Med 2010; 38:15421548, LaPrade RF, Matheny LM, Moulton SG, James EW, Dean CS. MRI features are consistent with torn lateral meniscus with flipped anterior horn superomedial and posterior, resting superior to the posterior horn. be misinterpreted for more significant pathology on MRI. Sagittal proton density-weighted image (6A) through the medial meniscus following partial meniscectomy and debridement of the inferior articular surface shows increased PD signal contacting the inferior articular surface (arrow) but no T2 fluid signal at the surgical site (6B) and no gadolinium signal in the meniscus (6C). 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. The symptoms Extension to the anterior cortex of . discoid lateral meniscus, including a propensity for tears to occur and The most widely used diagnostic modalities to assess the ligament injuries are arthroscopy and Magnetic Resonance Imaging (MRI). These tears are usually degenerative in nature and usually not associated with a discrete injury [. Pagnani M, Cooper D, Warren R. Extrusion of the Medial Meniscus. Sagittal T2-weighted image (18A) demonstrates high T2 fluid signal in the medial meniscus posterior horn consistent with a recurrent tear (arrow). Comparison of Medial and Lateral Meniscus Root Tears - PLOS However, recognizing these variants is important, as they can 9 The lateral meniscus is more loosely attached than the medial and can translate approximately 11mm with normal knee motion. Type As visualized on sagittal MR images, the anterior horn of the medial meniscus is shorter than the posterior horn, whereas the anterior and posterior horns of the lateral meniscus are of equal length. Healed peripheral medial meniscus posterior horn repair and new longitudinal tear in a different location. The Journal of bone and joint surgery American volume. patella or Hoffas fat pad, and should be fairly easily differentiated At the time the article was last revised Yahya Baba had 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 [. of the transverse ligament is comparable to the general population.5. Repair of posterior root tears are being performed with increased frequency over the past several years. Nakajima T, Nabeshima Y, Fujii H, et al. MRI appearance of Wrisberg variant of discoid lateral meniscus. The common insertion of the anterior cruciate ligament (ACL) and the AHLM root may provide a pathway for disease. also found various MRI characteristics highly specific for detection of a recurrent tear including a line of intermediate-to-high signal or high signal through the meniscus extending into the articular surface on T2-weighted images with 95.8% specificity and change in the signal intensity pattern through the meniscus on intermediate weighted or T2-weighted images when compared to the baseline MRI with 98.2% specificity. Meniscal tears were found on MRI or arthroscopy in all 28 patients with a lateral cyst overlying the body or posterior horn of the lateral meniscus, whereas a tear was found on MRI or arthroscopy in only 14 (64%) of 22 patients with cysts adjacent to or extending to the lateral meniscus anterior horn (p = 0.006). 800-688-2421. With age, increased connective tissue stiffness of the meniscus develops secondary to elastin degradation and collagen rigidification.2. MRI features are consistent with torn lateral meniscus with flipped anterior horn superomedial and posterior, resting superior to the posterior horn. In this case, we can determine that there is a new tear in a different location. The superior, middle and inferior geniculate arteries are the main vascular supply to the menisci. to the base of the ACL or the intercondylar notch. Heron, D, Bonnard C, Moraine C,Toutain A. Agenesis of cruciate History of medial meniscus posterior horn and body partial meniscectomy. Meniscus Tears: Understand your MRI results | Scott Hacker MD does not normally occur.13. Get unlimited access to our full publication and article library. 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. A meniscus is a crescent-shaped fibrocartilaginous structure that Increased intrameniscal signal is commonly seen in the transplanted allograft but does not correlate with clinical outcome. 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.
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