Lateral meniscus posterior horn peripheral longitudinal tear managed by repair. 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. They often tend to be radial tears extending into the meniscal root. Meniscal surgery is common and requires accurate post-operative imaging interpretation to guide the treatment approach. Renew or update your current subscription to Applied Radiology. and ACL tears can be mistaken for AIMM, but carefully tracing the diagnostic dilemma, as the AIMM band will be seen to extend to the The discoid lateral-meniscus syndrome. partly divides a joint cavity, unlike articular discs, which completely Rao PS, Rao SK, Paul R. Clinical, radiologic, and arthroscopic assessment of discoid lateral meniscus. Radial Tear of the Medial Meniscal Root: Reliability and Accuracy of MRI for Diagnosis. . The patient underwent an all-inside lateral meniscus repair. Pathology - a tear that has developed gradually in the meniscus. Fellowship-trained musculoskeletal radiologists read 99% of the MRIs. There was no evidence of meniscal extrusion or a meniscal ghost sign (Fig. A recurrent tear was proved at second look arthroscopy. Conventional MRI is useful for evaluation of posterior root morphology at the tibial tunnel fixation site, meniscal extrusion and articular cartilage. Arthroscopy: The Journal of Arthroscopic & Related Surgery. 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. MRI c spine / head jxn - they can have stenosis of foramen magnum . Clinical imaging. Bilateral complete discoid medial menisci combined with anomalous insertion and cyst formation. AJR Am J Roentgenol 211(3):519527, De Smet AA. Get unlimited access to our full publication and article library. Anomalous acromioclavicular, sternoclavicular, and temporomandibular joints. the example shown (Figures 1 and 2), the entire medial meniscus is Disadvantages include increased cost, increased patient time, potential for adverse reactions to contrast agent compared to conventional MRI and lack of joint distention. gestation, about the time when the knee joint is fully formed.1 Throughout fetal development, they found that the size of the lateral meniscus is highly variable, unlike the medial meniscus. The incidence was calculated based on arthroscopic findings, and the potential secondary signs of meniscal ramp tears were evaluated on MRI. 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). Case study, Radiopaedia.org (Accessed on 04 Mar 2023) https://doi.org/10.53347/rID-75066. They found that 76 (8%) of these indicated a tear of the anterior horn of either the medial or lateral meniscus. 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). Also, the inferior patella plica inserts on the Lee, J.W. The anterior and posterior sutures are shuttled down the tibial tunnel (arrowhead). You have reached your article limit for the month. An abnormal shape may indicate a meniscal tear or a partial meniscectomy. Evaluation of postoperative menisci with MR arthrography and routine conventional MRI. Radiographs are usually not diagnostic, but they may show a Imaging characteristics of the Pinar H, Akseki D, Karaoglan O, et al. High signal close to fluid intensity contacts the tibial surface on the sagittal T2-weighted image (11B) and is equivocal. Meniscal transplant is usually reserved for patients younger than 50 years who have normal axial alignment. The most commonly practiced ; Lee, S.H. Knee Surg Sports Traumatol Arthrosc. At 1 year, 5 of 6 were completely asymptomatic with the remaining patient minimally painful with no suggestion of meniscal symptoms. Diagnosis - clinical presentation with exclusion of advanced knee osteoarthritis. Dickhaut SC, DeLee JC. Wrisberg variant, the morphology of the meniscus may be normal, but the ligament, and the posterior horn may translate or rotate due to History of longitudinal medial meniscus tear managed by meniscal repair (arrows). Problems encountered in a discoid medial meniscus are the same as a 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. menisci develop from this mesenchymal tissue in a site where this tissue 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. Normal shape and signal of the horns of the medial meniscus, with no evidence of tears or degenerations seen. Root tears are associated with a high risk for osteoarthritis. Lateral meniscus bucket handle tears can produce the double anterior horn sign or double ACL sign. MR imaging and MR arthrography for diagnosis of recurrent tears in the postoperative meniscus. ligaments and menisci causing severe knee dysplasia in TAR syndrome. Because this is a relatively new procedure, few studies have been dedicated to MRI evaluation of postoperative root repair. Note the symmetrical shape of the lateral meniscus (left) with similar size of the anterior and posterior horns. 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. 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. 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). Arthroscopy for Medial Meniscus Tears The decision to repair or remove the torn portion is made at the time of surgery. The example above illustrates marked degenerative changes caused by loss of meniscal function. Conventional MRI imaging of the postop meniscus offers a noninvasive evaluation of the knee, but postoperative changes can mimic a recurrent or residual meniscus tear. Note that signal does not contact articular surface, The most common criterion for diagnosing meniscus tear on MRI is an increased signal extending in a line or band to the articular surface. 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. During an arthroscopy, we have the choice of either repairing the meniscus tear or removing the torn piece. There is no universally accepted system for classifying meniscal tear patterns. 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. The MRI sign of a radial tear is a linear, vertical cleft of abnormal high signal at the free edge (Fig. tissue only persists at the edges, where differentiation into the A 510, 210-pound 16-year-old male injured his left knee while kicking a football. 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). On MRI, longitudinal tears appear as a vertical line of abnormal signal contacting articular surface. 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). Type 2: An incomplete slab of meniscal tissue with 80% coverage of the lateral tibial plateau. 2059-2066, Kinsella S.D., and Carey J.L. Posteroinferior displacement of the meniscal tissue (arrowheads) is also diagnostic of recurrent tear. On MRI, they exhibit abnormal horizontal linear signal contacting the inferior articular surface near the free edge or less commonly the superior surface. Interested in Group Sales? The anomalous insertion 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. However, the tear changes plane of orientation over its course. Generally, A Study of Retrieved Allografts Used for ACL Surgery, Long-Term Results of Meniscus Allograft Transplantation with Concurrent ACL Reconstruction, Anterior Horn Meniscal Tears — Fact or Fiction, How Triathletes Can Use Cycling Cadence to Maximize Running Performance, Pharmacology Watch: HRT - Position Paper Places Benefits in Question, Clinical Briefs in Primary Care Supplement. Meniscal disorders: Normal, discoid, and cysts. 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. The condition is typically asymptomatic and, therefore, is infrequently diagnosed.14 Klingele KE, Kocher MS, Hresko MT, et al. Horizontal (degenerative) tears run relatively parallel the tibial plateau. In these cases, MR arthrography may provide additional diagnostic utility. an adult), and approximately twice the size of the anterior horn on Kim EY, Choi SH, Ahn JH, Kwon JW. Tolo VT. Congenital absence of the menisci and cruciate ligaments of the knee: A case report. tear. Pagnani M, Cooper D, Warren R. Extrusion of the Medial Meniscus. 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 Radial or oblique tear congurations close to or within the meniscus . This case is almost identical to the previous case with a different clinical history. medial meniscus are extremely uncommon and should not be a diagnostic Monllau et al in 1998 proposed adding a fourth type, It is often explained by fibers of the anterior cruciate ligament and the covering synovium . It is important to know the age of the patient when interpreting the MRI. The reported prevalence is 0.06% to 0.3%.25 The avulsed anterior horn of the lateral meniscus is flipped over and situated above the posterior horn. Meniscus tears are either degenerative or acute. They often tend to be radial tears extending into the meniscal root. Congenital absence of the meniscus is extremely rare and has been documented in TAR syndrome and in isolated case reports.2,3 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. At the time the article was created Yuranga Weerakkody had no recorded disclosures. This emphasizes the importance of baseline MRI comparison for evaluation of the postoperative meniscus.3. for the ratio of the sum of the width of the anterior and posterior A Wrisberg type variant has not been documented in Arthroscopy evaluation found a lateral meniscus peripheral (red-white zone) longitudinal tear. In cases like this, MR arthrography is quite helpful. posterior horn usually measures 12 mm to 16 mm in the sagittal plane in The shape of the meniscus is formed at the eighth week of Special thanks to David Rubin, MD for providing several cases used in this web clinic. in this case were attributed to an anterior cruciate ligament tear Fat suppressed sagittal T1-weighted MR arthrogram (5C) demonstrates gadolinium within the tear (arrow). meniscus are not uncommon; they include an anomalous insertion of the proximal medial tibia was convex and the distal medial femoral condyle Radiographic knee dimensions in discoid lateral meniscus: Comparison with normal control. | 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. medial meniscus, discoid lateral meniscus, including the Wrisberg There was no history of a specific knee injury. Following a meniscal repair procedure, the meniscus can be categorized as healed if there is no fluid signal in the repair, partially healed if fluid signal extends into less than 50% of the repair site, or not healed if fluid signal extends into greater than 50% of the repair site. 2012;20(10):2098-103. Continuous meniscal tissue bridged the anterior and posterior horns of the lateral meniscus on 3 consecutive sagittal slices (Figure 1B). The camera can visualize the meniscus and other structures within the knee. Brody J, Lin H, Hulstyn M, Tung G. Lateral Meniscus Root Tear and Meniscus Extrusion with Anterior Cruciate Ligament Tear. medial meniscus, and not be confined to the ACL as seen in an ACL tear. In this case, we can determine that there is a new tear in a different location. Papalia R, Vasta S, Franceschi F, D'Adamio S, Maffulli N, Denaro V. Meniscal Root Tears: From Basic Science to Ultimate Surgery. 1 ). An MRI of plaintiff's left knee conducted in May 2018 demonstrated a complex 7 tear of the posterior horn of the lateral meniscus and a suspected horizontal tear of the anterior horn of the lateral meniscus. The most important clinical concern at the time of MRI imaging is often high-grade articular cartilage loss. On the sagittal fat-suppressed T2-weighted image (7B), fluid extends into the tear. include hypoplastic menisci, absent menisci, anomalous insertion of the with mechanical features of clicking and locking. With age, increased connective tissue stiffness of the meniscus develops secondary to elastin degradation and collagen rigidification.2. The posterior root of the lateral meniscus (PRLM) attaches along the posterior aspect of the intercondylar eminence of the tibia (Fig. One important reason for such discrepancies is a failure to understand the transverse geniculate ligament of the knee (TGL). 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 anterior horn of the menisci, especially the lateral meniscus, is an area commonly confused on MRI. hypermobility. No meniscal tear is seen, but the root attachment was also noted to be was saddle shaped. Connolly B, Babyn PS, Wright JG, Thorner PS. In this section, the major patterns of tears are described and depicted in MRIs and arthroscopy images. (Tr. 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. variants of the meniscus are relatively uncommon and are frequently 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 Symptomatic anomalous insertion of the medial meniscus. A tear of the ACL should also, in practice, not be a [emailprotected]. 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. Among these 26 studies of an LMRT . of the transverse ligament is comparable to the general population.5. is in fact reducing the volume of the meniscus and restoring a normal The patient underwent partial medial meniscectomy and ACL reconstruction. 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. On imaging alone, the radiologist may not be able to distinguish a residual tear (failed repair) from a recurrent tear in the same location. 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. 2014; 43:10571064, McCauley TR. Meniscal root tears are a form of radial tear that involves the central attachment of the meniscus (12a). However, many clinicians opt to use conventional MRI as the initial postoperative imaging study and reserve MR arthrography for equivocal cases. 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. When evaluating a portion of the meniscus that is in a different location than the repair, criteria for evaluating a virgin meniscus may be used for that area. AJR Am J Roentgenol 2009;193:515-523. MR criteria are used to make the diagnosis. 1991;7(3):297-300. no specific MR criteria for classifying discoid medial menisci, and the Normal menisci. 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. of a case of discoid medial cartilage, with an embryological note. St. Louis County's newspaper of politics and culture Ross JA,Tough ICK, English TA. Tear between 1-4 cm vertical tear red-red meniscal root <40 yo Maybe concominant ACL surgery . The medial meniscus is more tightly anchored than the lateral meniscus, allowing for approximately 5mm of anterior-posterior translation. And, some tears do not fill with contrast during arthrography. Clark CR, Ogden JA. In this case the roots remained intact at the bone bridge, but the meniscal allograft detached from the joint capsule at the posterior and middle third with displacement into the central weightbearing surface (arrowheads) on sagittal T2-weighted (17C) and fat-suppressed axial proton density-weighted (17D) images. 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"}. The ends of the anterior and posterior horns are firmly attached to the tibia at their roots. Discoid lateral meniscus was originally believed to result from an This emphasizes the importance of meniscal repair over meniscectomy when possible and the need for meniscal preservation when a partial meniscectomy is necessary. Discoid lateral meniscus. Best assessed on T2 weighted sequences. The prevalence of a medial discoid meniscus in patients with AIMM 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. trials, alternative billing arrangements or group and site discounts please call 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. CT arthrography may be used to evaluate the postoperative meniscus when MRI is contraindicated. Is sport activity possible after arthroscopic meniscal allograft transplantation? Media community. Meniscal transplants can fail at the implantation site by avulsion, failure of bone plug incorporation or bone bridge fracture. MRI features are consistent with torn lateral meniscus with flipped anterior horn superomedial and posterior, resting superior to the posterior horn. They maintain a relatively constant distance from the periphery of the meniscus [. appearance.12 It is now believed that the knee develops from a If a meniscus tear shows up on a MRI, it is considered a Grade 3. Increased intrameniscal signal is commonly seen in the transplanted allograft but does not correlate with clinical outcome. There are Proper preoperative sizing of the allograft is critical for surgical success and usually performed with radiographs. high fibula head and a widened lateral joint space.20 Several 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. Grade II hyperintense horizontal signal of posterior horn of medial meniscus is noted. 1). show cupping of the medial tibial plateau, proximal medial tibial physis What causes abnormal mobility in the medial meniscus? 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). Anterior horn of the lateral meniscus: another potential pitfall in MR imaging of the knee. There De Smet A. Shepard and colleagues at UCLA specifically analyzed this by reviewing 947 consecutive MRIs. For information on new subscriptions, product Am J Sports Med 2016; 44:625632, De Smet AA, Horak DM, Davis KW, Choi JJ. A displaced longitudinal tear is a "bucket handle" tear. 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. The lateral . The medial meniscus covers 60% of the medial compartment. Of those 31 patients who underwent arthroscopic examination, there were only 8 true anterior horn tears (26% true positive rate) and 18 had normal or intact menisci in all zones. 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. Longitudinal medial meniscus tear managed by repair (arrow). The anterior meniscofemoral ligament (Humphrey ligament) attaches proximally on the medial femoral condyle, inferior to the PCL insertion. 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 the menisci of the knees. Sagittal proton density-weighted image (8A) through the medial meniscus demonstrates signal extending to the tibial surface (arrow). incomplete breakdown of the central meniscus, but this is now disputed, The patient subsequently underwent successful partial medial meniscectomy. This injury is biomechanically comparable to a total meniscectomy, leading to compromised hoop stressesresulting in decreased tibiofemoral contact area and increased contact pressures in the involved compartment.These changes are detrimental to the articular cartilage and . Otherwise, the increased vascularity in children has sometimes led to false-positive reading of a meniscus tear. instance, tears of the lateral aspect of the anterior horn of the Atypically thick and high location 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. History of a longitudinal medial meniscus tear managed by repair and concurrent ACL reconstruction. Again, this emphasizes the importance of accurate history, prior imaging and operative reports. 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. Meniscus tears, indicated by MRI, are classified in three grades. The ligament of Humphrey inserted on average 0.9 consecutive images lateral to the PCL without an PHLM tear and 4.7 with an PHLM tear; the ligament of Wrisberg inserted on average 3.0 consecutive images without an PHLM tear and 4.5 with an PHLM tear . Click to share on Twitter (Opens in new window), Click to share on Facebook (Opens in new window), Click to share on Google+ (Opens in new window), Posterior Instability and Labral Pathology, Imaging Evaluation of the Painful or Failed Shoulder Arthroplasty, Other Entities: PLRI, HO, Triceps, and Plica, MRI-Arthroscopy Correlations in the Overhead Athlete, Acetabular Fossa, Femoral Fovea, and the Ligamentum Teres. Additionally, the postoperative complication of new extensive synovitis is apparent on the axial view (18D). Description. 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 meniscal body is firmly attached to the deep portion of the medial collateral ligament complex via the meniscotibial ligament.
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