Root tears are associated with a high risk for osteoarthritis. We look forward to having you as a long-term member of the Relias Tear between 1-4 cm vertical tear red-red meniscal root <40 yo Maybe concominant ACL surgery . However, the tear changes plane of orientation over its course. Thirty-one of these patients underwent subsequent arthroscopic evaluation to allow clinical correlation. Kim SJ, Choi CH. 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. 2006; 187:W565568. Pinar H, Akseki D, Karaoglan O, et al. > 20% ratio of meniscus to tibia on the coronal image; Minimum diameter 14-15 mm on a midcoronal image; 75% Results: In a consecutive series of 301 ACL reconstructions, 50 patients (33 male, 17 female) with a mean age of 29.6 years (range, 14-61 years) were diagnosed with a medial meniscal ramp lesion at . [emailprotected]. 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. When the cruciate rim circumferentially, anteriorly, and posteriorly,19 which Type 1: A complete slab of meniscal tissue with complete tibial coverage. There is a medial and a lateral meniscus. Magnetic resonance imaging (MRI) revealed an elongated free edge of the diffusely enlarged lateral meniscus extending toward the intercondylar region on coronal T1-weighted images (Figure 1A). 300). attachment of the posterior horn is the Wrisberg meniscofemoral an adult), and approximately twice the size of the anterior horn on Check for errors and try again. normal knee. as at no time in development does the meniscus have a discoid 4). described in thrombocytopenia absent radius syndrome (TAR syndrome).2,3 Bilateral hypoplasia of the medial meniscus has also been reported.4. Monllau et al in 1998 proposed adding a fourth type, Long-term outcome after arthroscopic meniscal repair versus arthroscopic partial meniscectomy for traumatic meniscal tears. The common insertion of the anterior cruciate ligament (ACL) and the AHLM root may provide a pathway for disease. According to one source, they are thought to account for ~10% of all arthroscopic meniscectomies 5. Tibial meniscal dynamics using three-dimensional reconstruction of magnetic resonance images. Posterior root repair (Figure 16) is being performed with increasing frequency and has been shown to have better outcomes and decreased risk of osteoarthritis compared to posterior root tears treated non-operatively. Pain is typically medial and activity-related (e.g. are reported cases of complete absence of the medial meniscus as appearance.12 It is now believed that the knee develops from a Cho JM, Suh JS, Na JB, et al. 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. 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. Objectives: Low-field MRI at 0.55 Tesla (T) with deep learning image reconstruction has recently become commercially available. Longitudinal medial meniscus tear managed by repair (arrow). Description. There is no telling how much this error rate will change for radiologists less experienced with MRI. typically into the anterior cruciate ligament. 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 . Conventional MRI is useful for evaluation of posterior root morphology at the tibial tunnel fixation site, meniscal extrusion and articular cartilage. Discoid meniscus in children: Magnetic resonance imaging characteristics. 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. The fat-suppressed sagittal T1-weighted post arthrogram view (7C) demonstrates gadolinium extending into the meniscal substance. Am J Sports Med. History of longitudinal medial meniscus tear managed by meniscal repair (arrows). may simulate a peripheral tear (Figure 6).23 The only Congenital absence of the meniscus is extremely rare and has been documented in TAR syndrome and in isolated case reports.2,3 Grade II hyperintense horizontal signal of posterior horn of medial meniscus is noted. Sagittal T2-weighted (18B) and fat-suppressed sagittal proton density-weighted sagittal (18C) images demonstrate fluid-like signal in the posterior horn suggestive of a recurrent tear. They often tend to be radial tears extending into the meniscal root. 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. On the fat-supressed proton density-weighted coronal (17A) and axial (17B) images, notice the trapazoidal shaped bone bridge (arrow) placed in the tibial slot with menscal allograft attached at the anterior and posterior roots. 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. Sagittal proton density-weighted image (10A) demonstrates increased signal extending to the articular surface consistent with granulation tissue. instance, tears of the lateral aspect of the anterior horn of the The lateral meniscus is more circular, and its anterior and posterior horns are nearly equivalent in size in cross section. 2020;49(1):42-49. The meniscus is two crescent-shaped, thick pieces of cartilage that sit in the knee between the tibia and the femur. And, some tears do not fill with contrast during arthrography. 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 [. This article focuses on MRI plays a critical role in influencing the treatment decision and enables information that would obviate unnecessary surgery including diagnostic arthroscopy. insertion of the medial meniscus (AIMM) has been described, and it is Schwenke M, Singh M, Chow B Anterior Cruciate Ligament and Meniscal Tears: A Multi-modality Review. ; Lee, S.H. high fibula head and a widened lateral joint space.20 Several De Smet A. AJR Am J Roentgenol. 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. When bilateral, they are usually symmetric. This is a critical differentiation because the latter represents meniscal tears that can be Twenty-one had ACL tears; all those with an PHLM tear had an ACL tear. Youderian A, Chmell S, Stull MA. Presentation - Middle-older aged individuals, non-traumatic, progressive onset of pain. 2008; 32:212219, Magee T. Accuracy of 3-Tesla MR and MR arthrography in diagnosis of meniscal retear in the post-operative knee. 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. A previous study by De Smet et al. meniscal diameter. be misinterpreted for more significant pathology on MRI. Intensity of signal contacting meniscal surface in recurrent tears on MR arthrography compared with that of contrast material. show cupping of the medial tibial plateau, proximal medial tibial physis mimicking an anterior horn tear. of these meniscal variants is the discoid lateral meniscus, and the In some patients, hyperintense signal may persist at the repair site on conventional MRI for several years and is thought to represent granulation tissue. 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. reported.4. The anterior root of the medial meniscus attaches to the anterior midline of the tibial plateau or sometimes the anterior surface of the tibia just below the plateau. 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). 1. 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. Total meniscectomy is rarely performed unless the meniscus is so severely damaged that no salvageable meniscal tissue remains. Discoid lateral meniscus: Prevalence of peripheral rim instability. Tolo VT. Congenital absence of the menisci and cruciate ligaments of the knee: A case report. Volunteerism and Sports Medicine: Where do We Stand? A slightly overweight 44-year-old male sought evaluation for medial knee pain that persisted for months after running on the beach. One important reason for such discrepancies is a failure to understand the transverse geniculate ligament of the knee (TGL). The articular cartilage is well seen on the pre-operative sagittal proton density-weighted image (19B). Arthroscopy for Medial Meniscus Tears The decision to repair or remove the torn portion is made at the time of surgery. 1 ). If a meniscus tear shows up on a MRI, it is considered a Grade 3. Concise, to-the-point text covers MRI for the entire musculoskeletal system, presented in a highly templated format. Also, the inferior patella plica inserts on the 22 year-old male with a history of ACL and MCL reconstruction and medial meniscus posterior root repair. Best assessed on T2 weighted sequences. In the previously reported cases, as well as in this case, the What is your diagnosis? 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. Radiographs may Am J Sports Med 2017; 45:884891, Zaffagnini S, Grassi A, Marcheggiani Muccioli GM, et al. 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. This emphasizes the importance of meniscal repair over meniscectomy when possible and the need for meniscal preservation when a partial meniscectomy is necessary. discoid meniscus, although discoid medial menisci can occur much less Lateral Meniscus: Anatomy The lateral meniscus is seen as a symmetric bow tie in the sagittal plane on at least one or two sections before it divides into two asymmetric triangles near the midline. Meniscal transplant is usually reserved for patients younger than 50 years who have normal axial alignment. Sagittal T2-weighted image (18A) demonstrates high T2 fluid signal in the medial meniscus posterior horn consistent with a recurrent tear (arrow). This emphasizes the importance of baseline MRI comparison for evaluation of the postoperative meniscus.3. As a result, the accuracy rate of diagnosis by MRI is 83.3%. At the time the case was submitted for publication Mostafa El-Feky had no recorded disclosures. Midterm results in active patients. Collagen fibers are arranged for transferring compressive loads into circumferential hoop stresses, secured by radially oriented tie fibers. At surgery, the torn part of the meniscus was in the intercondylar notch and chewed up and not amenable to repair. Arthroscopy revealed a horizontal tear of PHMM, and a partial medial meniscectomy was performed. Shepard et al conclude that with a 74% false-positive rate, anterior horn tears should be treated surgically only if clinical correlation exists. diminutive (1 mm) with no increased signal to suggest root attachment These features constitute O'Donoghue unhappy triad. Repair techniques include side-to-side repair, stabilization with suture anchors, and the transtibial pull-out technique (figure 4).12. from AIMM. In this section, the major patterns of tears are described and depicted in MRIs and arthroscopy images. joint, and they also protect the hyaline cartilage. Laundre BJ, Collins MS, Bond JR, Dahm DL, Stuart MJ, Mandrekar JN: MRI accuracy for tears of the posterior horn of the lateral meniscus in patients with acute anterior cruciate ligament injury and the clinical relevance of missed tears. Normal course and intensity of both cruciate ligaments. pivoting). that this rare condition is also clinically asymptomatic. Torn lateral meniscus with superomedial and posterior flipped anterior horn. Nakajima T, Nabeshima Y, Fujii H, et al. However, many clinicians opt to use conventional MRI as the initial postoperative imaging study and reserve MR arthrography for equivocal cases. Become a Gold Supporter and see no third-party ads. The medial meniscus is more tightly anchored than the lateral meniscus, allowing for approximately 5mm of anterior-posterior translation. On MR arthrography, (12B), gadolinium extends through the repair site indicating a tear. In contrast to the medial meniscus, the posterior horn of the lateral meniscus is additionally secured by the meniscofemoral ligaments (MFL). ADVERTISEMENT: Supporters see fewer/no ads. 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. 7 Therefore, it is important for the radiologist to be familiar with the appearance of a recurrent tear versus an untorn postoperative meniscus. 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. The remaining 42 cases were located in the red zone (19 cases) or the red-white zone. Considered a feature of knee osteoarthritis. Lee, J.W. Partial meniscectomy is by far the most common procedure. joint: Morphologic changes and their potential role in childhood Clinical imaging. of a case of discoid medial cartilage, with an embryological note. 2012;20(10):2098-103. 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). 1427-143. Most patients are asymptomatic, but injury to the meniscus can Direct MR arthrography requires intraarticular injection of 20-50 mL of dilute gadolinium contrast prior to imaging which distends the joint capsule and offers a high signal to noise ratio on T1-weighted images with contrast extension into the meniscal substance indicating a recurrent tear or an unhealed repair. {"url":"/signup-modal-props.json?lang=us"}, Weerakkody Y, Baba Y, Knipe H, et al. Menisci are present in the knees and the (Figure 1). 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. Suprapatellar plica noticed, with no related cartilaginous erosions. the medial meniscus. Resnick D, Goergen TG, Kaye JJ, et al. Sagittal proton density-weighted image (7A) through the medial meniscus demonstrates increased signal extending to the tibial surface (arrow). 2014; 43:10571064, McCauley TR. meniscus is partial meniscal excision, leaving a 6- to 7-mm peripheral The MRI also demonstrated moderate degenerative spurring at the lateral joint compartment, a large knee joint effusion with . 5. intra-articular structures at 8 weeks gestation. MRI of the knee is commonly indicated for evaluation of unresolved or recurrent knee pain following meniscal surgery. The torn edges are aligned, and stable fixation applied with sutures or bioabsorbable implants at approximately 5 mm intervals. Anomalous The insertion site A tear of the lateral meniscus can occur from a sudden injury, or from chronic wear and overload. No paralabral cyst. Posterior meniscal root repairs: outcomes of an anatomic transtibial pull-out technique. MRI: When you tear your meniscus, a magnetic resonance imaging (MRI) scan will show the injury as white lines on black. Most horizontal tears extend to the inferior articular surface. Anatomic variability and increased signal change in this area are commonly mistaken for tears. frequently. 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. They often tend to be radial tears extending into the meniscal root. 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. On the proton density-weighted image (12A) persistent high signal extends to the tibial and femoral surfaces (arrow). Results: Arthroscopic examination of the anterior horn of the lateral meniscus in all 22 patients was normal. 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). It is important to know the age of the patient when interpreting the MRI. The lateral meniscus attaches to the popliteus tendon and capsule via the popliteomeniscal fascicles at the posterior horn and to the medial femoral condyle by the meniscofemoral ligaments. Recent evidence suggests that decreased extrusion may correlate to better clinical outcomes.18. If the tear does not show, it is considered a Grade 1 or 2 and is not as serious. The discoid lateral-meniscus syndrome. 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. 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. measurements of the posterior horn of the medial meniscus may vary, but of the anterior horn of the medial meniscus, an inferior patella plica, 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 tear of the ACL should also, in practice, not be a It is believed that discoid In Get unlimited access to our full publication and article library. The anomalous insertion Radiology. However, clinically significant tears that can mechanically impinge were unlikely to have been missed. Neuschwander DC, Drez D Jr, Finney TP. Kaplan EB. These tears are usually degenerative in nature and usually not associated with a discrete injury [. sagittal magnetic resonance (MR) images. At the time the article was created Yuranga Weerakkody had no recorded disclosures. Ross JA,Tough ICK, English TA. The congenitally absent meniscus appears to influence the development Root tears are often large radial tears that extend through the entire AP width of the meniscus. Kijowski et al. Relevant clinical history, prior imaging and use of operative reports will significantly improve accuracy of post-operative interpretations. problem in practice. menisci occurs. At 1 year, 5 of 6 were completely asymptomatic with the remaining patient minimally painful with no suggestion of meniscal symptoms. On examination, there was marked medial joint line tenderness and a large effusion. Pre-operative fat supressed coronal proton density-weighted image (19A) demonstates a posterior root radial tear (arrow). The patient subsequently underwent successful partial medial meniscectomy. However, recognizing these variants is important, as they can 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? AJR Am J Roentgenol. Bilateral hypoplasia of the medial meniscus has also been 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. Generally, For partial meniscectomies involving 25% or more, conventional MRI has lower accuracy. Following partial meniscectomy, the knee is at increased risk for osteoarthritis. Problems encountered in a discoid medial meniscus are the same as a 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. Both ligaments attach distally to the posterior horn of the lateral meniscus and contribute to posterior drawer stability . Exam showed a mild effusion and medial joint line tenderness. On MRI, they exhibit abnormal horizontal linear signal contacting the inferior articular surface near the free edge or less commonly the superior surface. discoid lateral meniscus, including a propensity for tears to occur and 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. Development of the menisci of the human knee Lateral meniscus extrusion was present in six (23%) of 26 LMRTs and five (2.2%) of 231 patients with normal meniscus roots ( P < .001).