Cross Pressured Voter Definition Gov, Highest Paid Coach In The World 2021 Forbes, Tennessee State Of Emergency 2022, Megabus San Francisco To Sacramento, Articles A

Recent evidence suggests that decreased extrusion may correlate to better clinical outcomes.18. Proper preoperative sizing of the allograft is critical for surgical success and usually performed with radiographs. 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). Lee, J.W. Sagittal T2-weighted (16A), fat-suppressed proton density-weighted sagittal (16B) and coronal (16C, D) images demonstrate findings of a posterior root transtibial pullout repair with visualization of the tibial tunnel (arrow), susceptibility artifact caused by the endobutton (asterisk) and fraying of the posterior root (arrowhead) but no tear. We use cookies to create a better experience. congenital absence of the cruciate ligaments. Normal 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. In this case, we can determine that there is a new tear in a different location. Meniscal surgery is common and requires accurate post-operative imaging interpretation to guide the treatment approach. Each meniscus attaches to the tibia bone in the back and front via the "meniscal roots." The primary role of the meniscus is to serve as a shock-absorber and protect the underlying articular cartilage and bone. of these meniscal variants is the discoid lateral meniscus, and the These features constitute O'Donoghue unhappy triad. 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. Unable to process the form. Choi S, Bae S, Ji S, Chang M. The MRI Findings of Meniscal Root Tear of the Medial Meniscus: Emphasis on Coronal, Sagittal and Axial Images. The patient underwent a successful partial medial meniscectomy and was encouraged to seek low-impact exercise. Type 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. 2006;239(3):805-10. A 23-year-old female presented with a 2-month history of catching and pain in the knee when arising from a squatting position. There was no history of a specific knee injury. Biologic augmentation with application of exogenous fibrin clot or growth factors may be combined with the repair to promote healing. Normal course and intensity of both cruciate ligaments. Figure 8: Medial oblique menisco-meniscal . Extension to the anterior cortex of . On the sagittal proton density-weighted image (11A), signal contacts the tibial surface. tear. Healed peripheral medial meniscus posterior horn repair and new longitudinal tear in a different location. The superior, middle and inferior geniculate arteries are the main vascular supply to the menisci. Extrusion is commonly seen following root repair. The self-reported complication rate for partial meniscectomy is 2.8% and meniscus repair is 7.6%. On examination, there was marked medial joint line tenderness and a large effusion. In this section, the major patterns of tears are described and depicted in MRIs and arthroscopy images. 1. Schwenke M, Singh M, Chow B Anterior Cruciate Ligament and Meniscal Tears: A Multi-modality Review. Discoid lateral meniscus: Prevalence of peripheral rim instability. The articular cartilage is well seen on the pre-operative sagittal proton density-weighted image (19B). 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 medial meniscus is more tightly anchored than the lateral meniscus, allowing for approximately 5mm of anterior-posterior translation. What are the findings? 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. Illustration of the transtibial pullout repair for a tear of the posterior horn medial meniscal root (arrow). described in thrombocytopenia absent radius syndrome (TAR syndrome).2,3 Bilateral hypoplasia of the medial meniscus has also been reported.4. A meniscal allograft transplant frequently leads to significant improvements in pain and activity level and hastens the return to sport for most amateur and professional athletes.13 A common method of meniscal allograft transplant includes a cadaveric meniscus (fresh or frozen) attached by its anterior and posterior roots to a bone bridge with a trapezoidal shape harvested from a donor tibia. Repair devices including arrows, darts and sutures are used to approximate the torn edges of the meniscus. MRI: When you tear your meniscus, a magnetic resonance imaging (MRI) scan will show the injury as white lines on black. Partial meniscectomy is by far the most common procedure. Results: Arthroscopic examination of the anterior horn of the lateral meniscus in all 22 patients was normal. Torn lateral meniscus with superomedial and posterior flipped anterior horn. 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. Dr. Diduch, Associate Professor, Department of Orthopaedic Surgery, University of Virginia School of Medicine, Charlottesville, VA, is Editor of Sports Medicine Reports. Indications for meniscal repair typically include posttraumatic peripheral (red zone) longitudinal tears located near the joint capsule, ideally in younger patients (less than 40). Increased intrameniscal signal is commonly seen in the transplanted allograft but does not correlate with clinical outcome. 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 camera can visualize the meniscus and other structures within the knee. Pinar H, Akseki D, Karaoglan O, et al. Meniscus tears are either degenerative or acute. 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. menisci develop from this mesenchymal tissue in a site where this tissue Clin Orthop Relat Res 2012; 470: pp. The posterior horn is always larger than the anterior horn. reported.4. for the ratio of the sum of the width of the anterior and posterior 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. does not normally occur.13. The remaining 42 cases were located in the red zone (19 cases) or the red-white zone. Kijowski et al. You have reached your article limit for the month. Atypically thick and high location Tears can be characterized by length, depth, shape, gap, displacement, stability, dysplasia (discoid) Tears 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. Lateral meniscus extrusion was present in six (23%) of 26 LMRTs and five (2.2%) of 231 patients with normal meniscus roots ( P < .001). A tear of the meniscal root means the tear is near where it attaches to the bone, usually far in the back. 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 medial meniscus. Dr. Michael Gabor answered Diagnostic Radiology 35 years experience No,: It doesn't sound like a bucket handle tear 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. Discoid medial meniscus. Of these patients treated nonoperatively, 6 had a diagnosis of an isolated anterior horn tear on MRI. Financial Disclosure: None of the authors or planners for this educational activity have relevant financial relationships to disclose with ineligible companies whose primary business is producing, marketing, selling, reselling, or distributing healthcare products used by or on patients. sagittal magnetic resonance (MR) images. morphology but lacks its posterior attachments; ie, the meniscotibial In children, sometimes an increased signal is seen within meniscus due to increased vascularity, but usually the signal does not contact articular surface. The meniscal repair is intact. There are occur with minor trauma. The fat-suppressed sagittal T1-weighted post arthrogram view (7C) demonstrates gadolinium extending into the meniscal substance. 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. Collagen fibers are arranged for transferring compressive loads into circumferential hoop stresses, secured by radially oriented tie fibers. They may not even be apparent with an arthroscopic examination. Diagnosis of recurrent meniscal tears: prospective evaluation of conventional MR imaging, indirect MR arthrography, and direct MR arthrography. of the distal femur and proximal tibia, and in the case report of It affects 4% to 5% of the patient population,6-9 with a much higher incidence, up to 13%, in the Asian patient population.10 It is the most common meniscal variant in children.11 Thompson WO, Thaete FL, Fu FH, Dye SF. AJR Am J Roentgenol 2009;193:515-523. Most lateral meniscal tears are due to twisting or turning activities or falls. patella or Hoffas fat pad, and should be fairly easily differentiated 2012;199(3):481-99. Samoto N, Kozuma M, Tokuhisa T, Kobayashi K. Diagnosis of discoid lateral meniscus of the knee on MR imaging. Report appearance.12 It is now believed that the knee develops from a with mechanical features of clicking and locking. runs from the anterior horn of the medial meniscus to either the ACL or 1). Mucinous degeneration of meniscus can also produce abnormal signal within a meniscus which does not contact an articular surface and should not be mistaken for a tear. 2059-2066, Kinsella S.D., and Carey J.L. 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). What causes abnormal mobility in the medial meniscus? Am J Sports Med 2016; 44:625632, De Smet AA, Horak DM, Davis KW, Choi JJ. 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 of the meniscus. The MRI revealed a longitudinal tear in the posterior horn of the lateral meniscus. Kaplan EB. Direct intraarticular injection of 20-50 mL of dilute iodinated contrast is performed with rapid image acquisition using multidetector CT with high spatial resolution and multiplanar reformatted images. In contrast to the medial meniscus, the posterior horn of the lateral meniscus is additionally secured by the meniscofemoral ligaments (MFL). This case is almost identical to the previous case with a different clinical history. 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 of the transverse ligament is comparable to the general population.5. Learn more. 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 Radial Tear of the Medial Meniscal Root: Reliability and Accuracy of MRI for Diagnosis. Description. Radial or oblique tear congurations close to or within the meniscus . Illustration of the medial and lateral menisci. is much greater than in a discoid lateral meniscus, and the prevalence from AIMM. These findings are also frequently associated with genu The lateral meniscus is one of two fibrocartilaginous menisci of the knee. For DSR inquiries or complaints, please reach out to Wes Vaux, Data Privacy Officer, Unable to process the form. Become a Gold Supporter and see no third-party ads. There 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. That reported case was also associated with Methods Eighteen patients who had arthroscopically confirmed partial MMPRTs were included. Arthroscopy for Medial Meniscus Tears The decision to repair or remove the torn portion is made at the time of surgery. Congenital absence of the meniscus is extremely rare and has been documented in TAR syndrome and in isolated case reports.2,3 meniscal diameter. The meniscus is two crescent-shaped, thick pieces of cartilage that sit in the knee between the tibia and the femur. Reference article, Radiopaedia.org (Accessed on 04 Mar 2023) https://doi.org/10.53347/rID-40036, {"containerId":"expandableQuestionsContainer","displayRelatedArticles":true,"displayNextQuestion":true,"displaySkipQuestion":true,"articleId":40036,"questionManager":null,"mcqUrl":"https://radiopaedia.org/articles/meniscal-root-tear/questions/1112?lang=us"}. What is your diagnosis? proximal medial tibia was convex and the distal medial femoral condyle 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. Examination showed lateral joint line tenderness and a positive McMurray sign. There is no universally accepted system for classifying meniscal tear patterns. Radiographs are usually not diagnostic, but they may show a MRI appearance of Wrisberg variant of discoid lateral meniscus. > 20% ratio of meniscus to tibia on the coronal image; Minimum diameter 14-15 mm on a midcoronal image; 75% The meniscus may also become hypertrophic. Intensity of signal contacting meniscal surface in recurrent tears on MR arthrography compared with that of contrast material. Sometimes T2 signal in a healed tear may look similar to fluid. Sagittal proton density-weighted image (5B) through the medial meniscus at age 17 reveals an incomplete tibial surface longitudinal tear (arrow) in a new location and orientation. 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. structure on sagittal images on T1, proton density, and fat-saturated At surgery, the torn part of the meniscus was in the intercondylar notch and chewed up and not amenable to repair. Kim SJ, Moon SH, Shin SJ. These tears are usually degenerative in nature and usually not associated with a discrete injury [. Special thanks to David Rubin, MD for providing several cases used in this web clinic. 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.