The fat-suppressed sagittal T1-weighted post arthrogram view (7C) demonstrates gadolinium extending into the meniscal substance. 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. 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. Special thanks to David Rubin, MD for providing several cases used in this web clinic. Pullout fixation of posterior medial meniscus root tears: correlation between meniscus extrusion and midterm clinical results. typically into the anterior cruciate ligament. 4). A 510, 210-pound 16-year-old male injured his left knee while kicking a football. 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 meniscal body is firmly attached to the deep portion of the medial collateral ligament complex via the meniscotibial ligament. Illustration of the medial and lateral menisci. MR criteria for discoid lateral menisci are used for discoid medial Meniscal transplants can fail at the implantation site by avulsion, failure of bone plug incorporation or bone bridge fracture. For partial meniscectomies involving 25% or more, conventional MRI has lower accuracy. While they can arise from a number of mechanisms, root tears are generally thought to be chronic 5. Symptoms of anterior horn tears were very similar to those of meniscal tears of the midbody or posterior horn, including catching, pain with knee flexion, and swelling. Similarly, the postoperative meniscus is at increased risk for a recurrent tear either at the same or different location due redistribution of forces and increased stress on the articular surface. Normal menisci. Knee Surg Sports Traumatol Arthrosc. medial meniscus, and not be confined to the ACL as seen in an ACL tear. It is often explained by fibers of the anterior cruciate ligament and the covering synovium . 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. MRI Knee - Sagittal PDFS - Displaced meniscus Part of a torn meniscus can be displaced into another part of the knee joint In this image the anterior part of the meniscus (the anterior horn) is correctly located The posterior horn is displaced such that it is located next to the anterior horn The correct position of the posterior horn is shown Am J Sports Med. These features constitute O'Donoghue unhappy triad. Discoid meniscus in children: Magnetic resonance imaging characteristics. Discoid lateral meniscus. Comparison of Postoperative Antibiotic Regimens for Complex Appendicitis: Is Two Days as Good as Five Days? (middle third), or Type 3 (superior third; intercondylar notch) (Figure Both ligaments attach distally to the posterior horn of the lateral meniscus and contribute to posterior drawer stability . Each meniscus has three main parts, the back (posterior horn), middle (body), and front (anterior horn). mobility, and a giving-way sensation.11, 15, 16 A high percentage of cases present with an associated meniscal tear and peripheral rim instability.9,16,17 Although discoid lateral meniscus is commonly bilateral, symptoms tend to occur on one side.15 It is characterized by an excess of meniscal tissue with a slab-like configuration in the 2 most common forms (Figure 5). A meta-analysis of 44 trials. What is a Grade 3 meniscus tear? In contrast to the medial meniscus, the posterior horn of the lateral meniscus is additionally secured by the meniscofemoral ligaments (MFL). 6. It is believed that discoid If the tear does not show, it is considered a Grade 1 or 2 and is not as serious. Most studies have shown increased accuracy for direct and indirect MR arthrography compared to conventional MRI for partial meniscectomies of 25% or more.16. Because this is a relatively new procedure, few studies have been dedicated to MRI evaluation of postoperative root repair. It is located in the lateral portion of the knee interior of the knee joint. Grade II hyperintense horizontal signal of posterior horn of medial meniscus is noted. Kijowski et al. The anterior horn of the menisci, especially the lateral meniscus, is an area commonly confused on MRI. Of the 14 athletes, 8 repairs were performed, 5 patients . Root tears are often large radial tears that extend through the entire AP width of the meniscus. 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. 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. In these cases, MR arthrography may provide additional diagnostic utility. At the time the case was submitted for publication Mostafa El-Feky had no recorded disclosures. The Journal of bone and joint surgery American volume. 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. Extrusion is commonly seen following root repair. 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. Pinar H, Akseki D, Karaoglan O, et al. RESULTS. MRI features are consistent with torn lateral meniscus with flipped anterior horn superomedial and posterior, resting superior to the posterior horn. Get unlimited access to our full publication and article library. 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"}. Youderian A, Chmell S, Stull MA. Interested in Group Sales? Tolo VT. Congenital absence of the menisci and cruciate ligaments of the knee: A case report. Arthroscopy evaluation found a lateral meniscus peripheral (red-white zone) longitudinal tear. 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. incomplete breakdown of the central meniscus, but this is now disputed, Normal The patient underwent partial medial meniscectomy and ACL reconstruction. If a horizontal tear involves a long segment of the meniscus, the central fragment may displace centrally from the peripheral portion of the meniscus [, Bucket handle tears (BHT) often cause pain and mechanical symptoms, such as locking, catching, and giving way [. The most commonly practiced AJR American journal of roentgenology. signal fluid cleft interposed between the posterior horn and the capsule 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. Semin Musculoskelet Radiol 2005;9(2):11624, Chung KS, Ha JK, Ra HJ, Nam GW, Kim JG. Menisci are present in the knees and the The ends of the anterior and posterior horns are firmly attached to the tibia at their roots. 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. That reported case was also associated with They are most frequently seen at the posterior horn of the medial meniscus. 7.2 Medial and Lateral Menisci Medial meniscus is larger than the lateral meniscus and is more "open" (=less C-like) and less wide. | 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. Findings indicate an intact meniscus following partial meniscectomy with normal intrameniscal signal. MRI Findings: Medial meniscus: Tear of the posterior horn seen to the inferior articular surface continuing into the posterior body and becoming more vertical. Samoto N, Kozuma M, Tokuhisa T, Kobayashi K. Diagnosis of discoid lateral meniscus of the knee on MR imaging. Diagnosis of recurrent meniscal tears: prospective evaluation of conventional MR imaging, indirect MR arthrography, and direct MR arthrography. runs from the anterior horn of the medial meniscus to either the ACL or It is important to know the age of the patient when interpreting the MRI. The lateral . 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). Lateral meniscus posterior horn peripheral longitudinal tear managed by repair. {"url":"/signup-modal-props.json?lang=us"}, Weerakkody Y, Baba Y, Knipe H, et al. Bilateral complete discoid medial menisci combined with anomalous insertion and cyst formation. The most frequent symptom is pain that usually begins with a minor 2002; 222:421429, Ciliz D, Ciliz A, Elverici E, Sakman B, Yuksel E, Akbulut O. (Figure 1). There was no history of a specific knee injury. The example above demonstrates the importance of baseline MRI comparison when evaluating the postoperative meniscus. The medial meniscus is more tightly anchored than the lateral meniscus, allowing for approximately 5mm of anterior-posterior translation. The MFL was not observed in five (19%) of 26 studies of an LMRT. Magnetic resonance imaging (MRI) is the most accurate imaging technique in the diagnosis of meniscal lesions and represents a standard tool in knee evaluation. joint: Morphologic changes and their potential role in childhood A slightly overweight 44-year-old male sought evaluation for medial knee pain that persisted for months after running on the beach. of the meniscus. 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 incidence was calculated based on arthroscopic findings, and the potential secondary signs of meniscal ramp tears were evaluated on MRI. 9 The lateral meniscus is more loosely attached than the medial and can translate approximately 11mm with normal knee motion. This arises from the posterior horn of the lateral meniscus and attaches to the lateral aspect of the medial femoral condyle. The camera can visualize the meniscus and other structures within the knee. 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. 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. At the time the article was created Yuranga Weerakkody had no recorded disclosures. Among these 26 studies of an LMRT . Knee Surg Sports Traumatol Arthrosc 2011; 19:147157, Gwathmey F.W., Golish S.R., Diduch D.R., et al: Complications in brief: meniscus repair. The trusted source for healthcare information and CONTINUING EDUCATION. Copy. variants of the meniscus are relatively uncommon and are frequently published a case series of anterior horn tears of the lateral meniscus in 14 soccer players (mean age 20.2 years). 2012;20(10):2098-103. of the AIMM into the ACL is classified as Type 1 (inferior third), Type 2 Radial tears comprise approximately 15 % of tears in some surgical series [. After failing conservative management with NSAIDs, PT, and activity modification, he underwent an MRI. The medial meniscus covers 60% of the medial compartment. Lateral meniscal variant with absence of the posterior coronary ligament. Disadvantages include increased cost, increased patient time, potential for adverse reactions to contrast agent compared to conventional MRI and lack of joint distention. 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. Figure 7: Meniscofemoral ligament. Normal Congenital absence of the meniscus is extremely rare and has been documented in TAR syndrome and in isolated case reports.2,3 There are 3 main types, according to the Watanabe classification:18. Meniscus tears are either degenerative or acute. However, few studies have directly compared the medial and lateral root tears. ligament will help to exclude these conditions.5 In the first History of a longitudinal medial meniscus tear managed by repair and concurrent ACL reconstruction. It has been calculated that the lateral meniscus absorbs about 70% of the forces across the lateral compartment of the knee. Studies on meniscus root tears have investigated the relationship of osteoarthritis and an anterior cruciate ligament tear. There are The MRI revealed a vertical flap (oblique) tear of the medial meniscus. Unable to process the form. Anterior lateral cysts extended . The lateral meniscus is more circular, and its anterior and posterior horns are nearly equivalent in size in cross section. They maintain a relatively constant distance from the periphery of the meniscus [. Discoid lateral meniscus: Prevalence of peripheral rim instability. 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). A 22-years old male presented with injury to right knee in a road traffic accident MRI images shows double posterior horn of lateral meniscus and absent anterior horn in coronal (A: PD; B: STIR; C . ligaments and menisci causing severe knee dysplasia in TAR syndrome. Biologic augmentation with application of exogenous fibrin clot or growth factors may be combined with the repair to promote healing. Sagittal proton density-weighted image (7A) through the medial meniscus demonstrates increased signal extending to the tibial surface (arrow). Anatomic variability and increased signal change in this area are commonly mistaken for tears. meniscal injury. The posterior root of the medial meniscus attaches to the tibia, just anterior and medial to the posterior cruciate ligament (PCL). Of the anterior horn tears read on MRI, 85% involved the lateral meniscus anterior horn and about one half were judged to extend into the middle or body of the same meniscus. The meniscus is diffusely vascularized in early life but in adults, only 10-30% of the peripheral meniscus is vascularized, often referred to as the red zone. A tear of the ACL should also, in practice, not be a A tear of the meniscal root means the tear is near where it attaches to the bone, usually far in the back. 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. 2008; 32:212219, Magee T. Accuracy of 3-Tesla MR and MR arthrography in diagnosis of meniscal retear in the post-operative knee. The patient subsequently underwent successful partial medial meniscectomy. Magnetic Resonance Imaging Arthroscopy Orthodontic Extrusion Anterior Cruciate Ligament Reconstruction Arthroscopes Suture Anchors Tissue Culture Techniques Tissue Engineering Injections, Intra-Articular Range of Motion, Articular Arthrography Hardness Tests Orthopedic Procedures Monllau et al in 1998 proposed adding a fourth type, of these meniscal variants is the discoid lateral meniscus, and the The anterior and posterior meniscofemoral ligaments (Humphrey and Wrisberg respectively) are commonly present with one or both found in 93-100% of patients.9 The lateral meniscus is more loosely attached than the medial and can translate approximately 11mm with normal knee motion.10. Meniscal root tears are a form of radial tear that involves the central attachment of the meniscus (12a). Stay up to date with the latest in Practical Medical Imaging and Management with Applied Radiology. Bilateral hypoplasia of the medial meniscus has also been The most important clinical concern at the time of MRI imaging is often high-grade articular cartilage loss. This scan showed a radial MMT. Another MRI was later performed due to worsening symptoms, and demonstrated a bucket-handle tear with complete anterior luxation of the posterior horn of the left lateral meniscus (Figs. However, the tear changes plane of orientation over its course. Menisci ensure normal function of the On examination, the patient had medial joint line tenderness with positive McMurray test. Papalia R, Vasta S, Franceschi F, D'Adamio S, Maffulli N, Denaro V. Meniscal Root Tears: From Basic Science to Ultimate Surgery. The self-reported complication rate for partial meniscectomy is 2.8% and meniscus repair is 7.6%. Relevant clinical history, prior imaging and use of operative reports will significantly improve accuracy of post-operative interpretations. The main functions The patient underwent meniscal repair but had recurrent pain prompting repeat MRI 8 months post-operative. 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. 6 months post-operative she had increased pain prompting follow-up MRI. 2006; 187:W565568. 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. Resnick D, Goergen TG, Kaye JJ, et al. The discoid lateral-meniscus syndrome. History of longitudinal medial meniscus tear managed by meniscal repair (arrows). Most lateral meniscal tears are due to twisting or turning activities or falls. Bilateral discoid medial menisci: Case report. Horizontal (degenerative) tears run relatively parallel the tibial plateau. Longitudinal medial meniscus tear managed by repair (arrow). Anatomic variability and increased signal change in this area are commonly mistaken for tears. Figure 8: Medial oblique menisco-meniscal . A Wrisberg type variant has not been documented in They were first described by M J Pagnaniet al. They may not even be apparent with an arthroscopic examination. There was no evidence of meniscal extrusion or a meniscal ghost sign (Fig. [emailprotected]. Type The anterior horn of the menisci, especially the lateral meniscus, is an area commonly confused on MRI. hypermobility. Meniscal root tears are a type of meniscal tear in the knee where the tear extends to either the anterior or posterior meniscal root attachment to the central tibial plateau. If missing on MR images, a posterior root tear is present. The meniscus can separate from the joint capsule or tear through the allograft. The lateral meniscus is more circular, and its anterior and posterior horns are nearly equivalent in size in cross section. 1. Proper preoperative sizing of the allograft is critical for surgical success and usually performed with radiographs. 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 menisci (Figure 8). 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. Medial meniscus bucket handle tears can result in a double PCL sign. 2a, 2b, 2c). found that the absence of a line of increased signal through the meniscus extending to the articular surface on proton density and T2-weighted images was a reliable MRI finding for an untorn post-operative meniscus with 100% sensitivity. Radiology. Both horns of the medial meniscus are triangular with sharp points. A detached posterior root is functionally equivalent to a total meniscectomy with loss of its ability to withstand hoop stress. least common is complete congenital absence of the menisci. Meniscal surgery is common and requires accurate post-operative imaging interpretation to guide the treatment approach. Generally, Considered a feature of knee osteoarthritis. The patient had a recent new injury with increased pain. A displaced longitudinal tear is a "bucket handle" tear. Am J Sports Med 2010; 38:15421548, LaPrade RF, Matheny LM, Moulton SG, James EW, Dean CS. that this rare condition is also clinically asymptomatic. trauma; however, other symptoms include clicking, snapping, and locking ; Lee, S.H. 3 is least common. Lateral meniscus tears of the posterior root are a common concomitant injury to anterior cruciate ligament (ACL) tears [6, 16, 20]. The MRI showed complete ACL tear with displaced bucket handle medial meniscus tear. 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). 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. 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. treatment for stable complete or incomplete types of discoid lateral congenital anomalies affect the lateral meniscus, most commonly a 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. snapping knee due to hypermobility. Rao PS, Rao SK, Paul R. Clinical, radiologic, and arthroscopic assessment of discoid lateral meniscus. are reported cases of complete absence of the medial meniscus as . The most common Grade 3 is a true meniscus tear and an arthroscope is close to 100 percent accurate in diagnosing this tear. in 19916. Surgical Outcomes Lysholm Score 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. morphology but lacks its posterior attachments; ie, the meniscotibial Total meniscectomy is rarely performed unless the meniscus is so severely damaged that no salvageable meniscal tissue remains. And, some tears do not fill with contrast during arthrography. 2002;30(2):189-192. MR imaging is useful for evaluation of many possible complications following meniscal surgery. MRI showed posterior horn of the medial meniscus (PHMM) horizontal tear with early degenerative changes. (1A) Proton density-weighted, (1B) T2-weighted, and (1C) fat-suppressed T1-weighted MR arthrographic sagittal images are provided. 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. Increased intrameniscal signal is commonly seen in the transplanted allograft but does not correlate with clinical outcome. Indications for meniscal repair typically include posttraumatic peripheral (red zone) longitudinal tears located near the joint capsule, ideally in younger patients (less than 40). Methods Eighteen patients who had arthroscopically confirmed partial MMPRTs were included. A tear of the anterior horn of the lateral meniscus is damage to the front part of one of the two structures that act as shock absorbers between the thigh bone and the lower leg, explains The Steadman Clinic. Collagen fibers are arranged for transferring compressive loads into circumferential hoop stresses, secured by radially oriented tie fibers. The lateral meniscus is one of two fibrocartilaginous menisci of the knee. posterior horn usually measures 12 mm to 16 mm in the sagittal plane in to tear. An intact meniscal repair was confirmed at second look arthroscopy. Monllau J, Gonzalez G, Puig L, Caceres E. Bilateral hypoplasia of the medial meniscus. 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