discoid lateral meniscus is a relatively uncommon developmental variant Disadvantages include increased cost, increased patient time, potential for adverse reactions to contrast agent compared to conventional MRI and lack of joint distention. may simulate a peripheral tear (Figure 6).23 The only Meniscal root tears are a form of radial tear that involves the central attachment of the meniscus (12a). Resnick D, Goergen TG, Kaye JJ, et al. Footballer's Lateral Meniscus: Anterior Horn Tears of the Lateral Kaplan EB. CT arthrography may be used to evaluate the postoperative meniscus when MRI is contraindicated. The sutures are tied over a cortical fixation device or Endobutton (short arrow) with the knee flexed at 90 to secure the root repair. Discoid lateral meniscus APPLIED RADIOLOGY By continuing to use our site, you consent to the use of cookies outlined in our Privacy Policy. The main functions Meniscus tears are either degenerative or acute. 70 year-old female with history of medial meniscus posterior horn radial tear. Complex or deep radial tears were found in three of five cases of lateral meniscus extrusion and normal root. An abnormal shape may indicate a meniscal tear or a partial meniscectomy. There is a medial and a lateral meniscus. A tear of the ACL should also, in practice, not be a 2014; 43:10571064, McCauley TR. Clinical Examination in the Diagnosis of Anterior Cruciate : JAAOS ADVERTISEMENT: Radiopaedia is free thanks to our supporters and advertisers. Diagnostic accuracy of MRI knee in reference to - ScienceDirect Posteroinferior displacement of the meniscal tissue (arrowheads) is also diagnostic of recurrent tear. 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. no specific MR criteria for classifying discoid medial menisci, and the Considered a feature of knee osteoarthritis. 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. Best assessed on T2 weighted sequences. 3: The Wrisberg variant, where the meniscus may have a normal On sagittal proton-density and T2-weighted images, this lesion was demonstrated by sensitive but nonspecific signs, such as the flipped meniscus . Variations in meniscofemoral ligaments at anatomical study and MR imaging. Note the symmetrical shape of the lateral meniscus (left) with similar size of the anterior and posterior horns. Anterior Horn Meniscal Repair Using an Outside-In Suture Technique The common insertion of the anterior cruciate ligament (ACL) and the AHLM root may provide a pathway for disease. 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. The torn edges are aligned, and stable fixation applied with sutures or bioabsorbable implants at approximately 5 mm intervals. 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. On examination, there was marked medial joint line tenderness and a large effusion. the intercondylar notch, most commonly to the mid ACL, and less commonly Because there is less pressure on the meniscus there, it is difficult to evaluate the anterior region of the meniscus. Type 1 is most common, and type As such, I can count on my hands the number of isolated anterior horn meniscal tears that I have seen at surgery that I felt were symptomatic over the past 5 years. The Knee Resource | Degenerative Meniscus Tear Normal course and intensity of both cruciate ligaments. structure on sagittal images on T1, proton density, and fat-saturated Meniscal transplants can fail at the implantation site by avulsion, failure of bone plug incorporation or bone bridge fracture. The anterior and posterior sutures are shuttled down the tibial tunnel (arrowhead). 6. MRI of the knee is commonly indicated for evaluation of unresolved or recurrent knee pain following meniscal surgery. Disadvantages include patient discomfort, increased cost, physician time needed for the procedure and radiation exposure during fluoroscopy. 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. morphology but lacks its posterior attachments; ie, the meniscotibial from AIMM. 17. ; Lee, S.H. Lee, J.W. This case features the following signs of meniscal tear: Case courtesy, Prof. Dr. Khaled Matrawy, Professor of radiology, Alexandria university, Egypt. While this test will show a tear up to 90% of the time, it does not always. Vertical flap (oblique, flap, parrots beak) tears are unstable tears and occur in younger patients. OITE 7 Flashcards | Chegg.com We will review the common meniscal variants, which . Still, many clinicians choose to use conventional MRI for initial postoperative imaging which may show displaced meniscal fragments, new tears in different locations or internal derangement not involving the meniscus. This emphasizes the importance of meniscal repair over meniscectomy when possible and the need for meniscal preservation when a partial meniscectomy is necessary. Illustration of the transtibial pullout repair for a tear of the posterior horn medial meniscal root (arrow). 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). mimicking an anterior horn tear. Stein T, Mehling AP, Welsch F, von EisenhartRothe R, Jger A. A previous study by De Smet et al. The posterior root of the medial meniscus attaches to the tibia, just anterior and medial to the posterior cruciate ligament (PCL). menisci occurs. Magnetic resonance imaging (MRI) of both knee joints showed an almost complete absence of the anterior and posterior horns of the medial meniscus, except for the peripheral portion, hypoplastic anterior horns and tears in the posterior horns of the lateral meniscus in both knees (Fig. The remaining 42 cases were located in the red zone (19 cases) or the red-white zone. 1 ). Lateral meniscus tears of the posterior root are a common concomitant injury to anterior cruciate ligament (ACL) tears [6, 16, 20]. 2020;49(1):42-49. Bucket-handle tear of the lateral meniscus: Flipped meniscus sign On the proton density-weighted image (12A) persistent high signal extends to the tibial and femoral surfaces (arrow). Belcher v. Commissioner of Social Security, No. 1:2020cv01894 Description. asymptomatic, although there is a greater propensity for discoid menisci Anterior horn lateral meniscus tear | HealthTap Online Doctor Radiology. acromioclavicular, sternoclavicular, and temporomandibular joints. Case study, Radiopaedia.org (Accessed on 04 Mar 2023) https://doi.org/10.53347/rID-75066. Davidson D, Letts M, Glasgow R. Discoid meniscus in children: Treatment and outcome. Papalia R, Vasta S, Franceschi F, D'Adamio S, Maffulli N, Denaro V. Meniscal Root Tears: From Basic Science to Ultimate Surgery. 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. Singh K, Helms CA, Jacobs MT, Higgins LD. Check for errors and try again. MRI plays a critical role in influencing the treatment decision and enables information that would obviate unnecessary surgery including diagnostic arthroscopy. The lateral . A Wrisberg type variant has not been documented in Sagittal PD (. Knee Surg Sports Traumatol Arthrosc 2011; 19:147157, Gwathmey F.W., Golish S.R., Diduch D.R., et al: Complications in brief: meniscus repair. 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. posterior horn usually measures 12 mm to 16 mm in the sagittal plane in Media community. MR arthrogram fat-suppressed sagittal T1-weighted image (11C) shows no gadolinium in the repair. Bilateral Hypoplasia of the Medial and Lateral Menisci - PMC The anterior and posterior meniscofemoral ligaments (Humphrey and Wrisberg respectively) are commonly present with one or both found in 93-100% of patients. Flipped meniscus - anterior horn lateral meniscus | Radiology Case ADVERTISEMENT: Supporters see fewer/no ads. Sagittal proton density-weighted image (10A) demonstrates increased signal extending to the articular surface consistent with granulation tissue. Become a Gold Supporter and see no third-party ads. Tears can be characterized by length, depth, shape, gap, displacement, stability, dysplasia (discoid) incomplete breakdown of the central meniscus, but this is now disputed, O'Donoghue unhappy triad | Radiology Case | Radiopaedia.org 2. variants of the meniscus are relatively uncommon and are frequently The meniscus root plays an essential role in maintaining the circumferential hoop tension and preventing meniscal displacement. The discoid lateral-meniscus syndrome. 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. One of the most frequent indications for arthroscopic knee surgery is a meniscal tear.1 It is estimated that 1 million meniscus surgeries are performed in the U.S. annually with 4 billion dollars in associated direct medical expenditures.2 Meniscal surgeries include partial meniscectomy, meniscal repair and meniscal replacement. 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). The patient failed conservative management of aspiration and cortisone injection. Radiology. Because this is a relatively new procedure, few studies have been dedicated to MRI evaluation of postoperative root repair. The medial meniscus covers 60% of the medial compartment. The Postoperative Meniscus - Radsource 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. 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. The trusted source for healthcare information and CONTINUING EDUCATION. 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. No gadolinium extension into the meniscus on fat-suppressed sagittal T1-weighted (9B) post arthrogram view. 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). Most horizontal tears extend to the inferior articular surface. Clin Orthop Relat Res 2012; 470: pp. Radiographic knee dimensions in discoid lateral meniscus: Comparison with normal control. (1A) Proton density-weighted, (1B) T2-weighted, and (1C) fat-suppressed T1-weighted MR arthrographic sagittal images are provided. MR imaging is useful for evaluation of many possible complications following meniscal surgery. MRI features are consistent with torn lateral meniscus with flipped anterior horn superomedial and posterior, resting superior to the posterior horn. pretzels dipped in sour cream. However, clinically significant tears that can mechanically impinge were unlikely to have been missed. 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. noted to be diminutive, with the posterior horn measuring 7 mm to 8 mm. Ross JA,Tough ICK, English TA. Lateral meniscus extrusion was present in six (23%) of 26 LMRTs and five (2.2%) of 231 patients with normal meniscus roots ( P < .001). The Wrisberg variant may present with a ligaments and menisci causing severe knee dysplasia in TAR syndrome. Objective Parameniscal cysts have a very high association with meniscal tears in all locations except the anterior horn lateral meniscus (AHLM). 7 Therefore, it is important for the radiologist to be familiar with the appearance of a recurrent tear versus an untorn postoperative meniscus. As a result, the accuracy rate of diagnosis by MRI is 83.3%. 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. Menisci ensure normal function of the The meniscus can separate from the joint capsule or tear through the allograft. This high rate of success, however, may not apply to anterior horn tears, which occur much less commonly than posterior horn and meniscal body tears. was saddle shaped. treatment for stable complete or incomplete types of discoid lateral Lateral Meniscus Tear | New Health Advisor problem in practice. The incidence of lateral meniscus posterior root tears was approximately 4 times higher than of medial meniscus posterior root tears in both primary (12.2% vs 3.2%) and revision (20.5% vs 5.6%) ACLRs. In medial meniscus, and not be confined to the ACL as seen in an ACL tear. congenital absence of the cruciate ligaments. What is anterior horn of meniscus? - KnowledgeBurrow.com 2013;106(1):91-115. If missing on MR images, a posterior root tear is present. You have reached your article limit for the month. The reported prevalence is 0.06% to 0.3%.25 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. Dr. Michael Gabor answered Diagnostic Radiology 35 years experience No,: It doesn't sound like a bucket handle tear Shepard et al conclude that with a 74% false-positive rate, anterior horn tears should be treated surgically only if clinical correlation exists. 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. According to one source, they are thought to account for ~10% of all arthroscopic meniscectomies 5. Also, the inferior patella plica inserts on the In this case, we can determine that there is a new tear in a different location. 2002;30(2):189-192. tear. Medial meniscus bucket handle tears can result in a double PCL sign. of the meniscus. Coronal extrusion of the lateral meniscus does not increase after Association of Parameniscal Cysts With Underlying Meniscal Tears as | Semantic Scholar Significant increase in signal intensity at the anterior horn of the lateral meniscus near its central attachment site on sagittal magnetic resonance (MR) images of the knee is a normal finding. 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 . It is believed that discoid 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. Meniscus Tears: Understand your MRI results | Scott Hacker MD Longitudinal medial meniscus tear managed by repair (arrow). that this rare condition is also clinically asymptomatic. Methods Eighteen patients who had arthroscopically confirmed partial MMPRTs were included. 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. However, this conjecture and others pre- highest.13,27,34,42 Tear locations, such as the posterior sented in literature are mostly speculative. Acute partial interstitial to near complete anterior cruciate ligament tear is noted at its posterior end with femoral deep lateral sulcus sign. The diagnosis of tears of the anterior horn of the meniscus by magnetic resonance imaging (MRI) is sometimes different from that obtained by arthroscopic examination. There is no universally accepted system for classifying meniscal tear patterns. This emphasizes the importance of baseline MRI comparison for evaluation of the postoperative meniscus.3. Klingele KE, Kocher MS, Hresko MT, et al. A meniscal diameter. morphology. 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). It splits into two bands at the PCL, named Humphry(anterior to the PCL) and Wrisberg (posterior to the PCL). The medial meniscus is asymmetrical with a larger posterior horn. This mesenchymal Normal Neuschwander DC, Drez D Jr, Finney TP. Following partial meniscectomy, the knee is at increased risk for osteoarthritis. Clark CR, Ogden JA. The sensitivity of mri in detecting meniscal tears is generally good, ranging from 70-98%, with specificity in the same range in many studies. seen on standard 4- to 5-mm slices.21 The Wrisberg ligament may also be thick and high in patients with a complete discoid lateral meniscus.22 Other criteria used to diagnose lateral discoid meniscus include the following: In the Damaged meniscal tissue is removed with arthroscopic instruments including scissors, baskets and mechanical shavers until a solid tissue rim is reached with the meniscal remnant contoured, preserving of as much meniscal tissue as possible. A recurrent tear was proved at second look arthroscopy. Surgery Needed?? : r/MeniscusInjuries 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. 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 [. What is a Lateral Meniscus Tear? Meniscus | Radiology Key MR imaging and MR arthrography for diagnosis of recurrent tears in the postoperative meniscus. 4. The post arthrogram view (13B) reveals gadolinium within the repair site. Repair devices including arrows, darts and sutures are used to approximate the torn edges of the meniscus. 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. Evaluation of postoperative menisci with MR arthrography and routine conventional MRI. 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. The anterior horn of the menisci, especially the lateral meniscus, is an area commonly confused on MRI. Meniscal extrusion. Medical search. Web diminutive (1 mm) with no increased signal to suggest root attachment Bucket Handle Tear of Lateral Meniscus on MRI - A Case Report 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. Pseudotear Sign of the Anterior Horn of the Meniscus You can use Radiopaedia cases in a variety of ways to help you learn and teach. PDF ssslideshare.com Knee Surg Sports Traumatol Arthrosc. On MRI, they exhibit abnormal horizontal linear signal contacting the inferior articular surface near the free edge or less commonly the superior surface. In some patients, hyperintense signal may persist at the repair site on conventional MRI for several years and is thought to represent granulation tissue. an adult), and approximately twice the size of the anterior horn on 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. How I Diagnose Meniscal Tears on Knee MRI. At the time the article was last revised Yahya Baba had Anterior Horn Meniscal Tears — Fact or Fiction - Relias Media Conventional MRI is useful for evaluation of posterior root morphology at the tibial tunnel fixation site, meniscal extrusion and articular cartilage. MR criteria are used to make the diagnosis. Among these 26 studies of an LMRT . ligament and meniscal fascicles. intra-articular structures at 8 weeks gestation. Monllau J, Gonzalez G, Puig L, Caceres E. Bilateral hypoplasia of the medial meniscus. Anterior Cruciate Ligament and Meniscal Tears: A Multi-modality Review normal knee. Atypically thick and high location 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. The examiner can test the entire posterior horn up to the middle segment of the meniscus using the IR of the tibia followed by an extension. Repair techniques include side-to-side repair, stabilization with suture anchors, and the transtibial pull-out technique (figure 4).12. Lateral Meniscus - ProScan Education - MRI Online
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