Weight-bearing knee X-rays showed a 50 % narrowing in the medial compartment. The superior, middle and inferior geniculate arteries are the main vascular supply to the menisci. Kim EY, Choi SH, Ahn JH, Kwon JW. 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. During an arthroscopy, we have the choice of either repairing the meniscus tear or removing the torn piece. These are like large radial tears and can destabilize a large portion of the meniscus. Lee S, Jee W, Kim J. It is usually seen near the lateral meniscus central attachment site. 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. 2006; 187:W565568. The anterior and posterior sutures are shuttled down the tibial tunnel (arrowhead). Learn more. Lee, J.W. Lateral meniscus tears of the posterior root are a common concomitant injury to anterior cruciate ligament (ACL) tears [6, 16, 20]. . Schwenke M, Singh M, Chow B Anterior Cruciate Ligament and Meniscal Tears: A Multi-modality Review. For information on new subscriptions, product 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. Extension to the anterior cortex of . 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? Of the 54 participants, 5 had PHLM tears and 49 were normal. This article focuses on Meniscal root tears are defined as radial tears located within 1 cm from the meniscal attachment or a bony rootavulsion. reported.4. When the cruciate in 19916. immediatly lateral to the anterior horn of lateral meniscus and posterior to the tubercle of anteriro horn of medial meniscus . 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. Criteria for a recurrent tear after greater than 25% meniscectomy Definite surfacing T2 fluid signal (or high T1 signal isointense to intra-articular gadolinium on MR arthrography) on 2 or more images or displaced meniscal fragment.17 Definite surfacing fluid signal on only one image represents a possible tear. Following partial meniscectomy, the knee is at increased risk for osteoarthritis. 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. 2008; 32:212219, Magee T. Accuracy of 3-Tesla MR and MR arthrography in diagnosis of meniscal retear in the post-operative knee. 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. 1. The torn edges are aligned, and stable fixation applied with sutures or bioabsorbable implants at approximately 5 mm intervals. Generally, hypermobility. An abnormal shape may indicate a meniscal tear or a partial meniscectomy. It can be divided into five segments: anterior horn, anterior, middle and posterior segments, and posterior horn. AJR Am J Roentgenol 211(3):519527, De Smet AA. 1). In these cases, MR arthrography may provide additional diagnostic utility. We look forward to having you as a long-term member of the Relias The patient underwent partial medial meniscectomy and ACL reconstruction. 3 is least common. Normal menisci. Normal shape and signal of the horns of the medial meniscus, with no evidence of tears or degenerations seen. show cupping of the medial tibial plateau, proximal medial tibial physis Kijowski et al. Clinical imaging. of these meniscal variants is the discoid lateral meniscus, and the Heron, D, Bonnard C, Moraine C,Toutain A. Agenesis of cruciate 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. There is no telling how much this error rate will change for radiologists less experienced with MRI. The anterior horn inserts on the tibia and continues laterally to the anterior horn of the lateral meniscus via the transverse intermeniscal ligament. AJR Am J Roentgenol. Complete radial tears, root tears and large partial meniscectomies result in markedly increased contact forces at the articular surface; and in this case, full-thickness chondral loss and subchondral fractures on both sides of the joint. 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. (Figure 1). The most commonly practiced 2. Sagittal proton density (PD) images through normal medial (, The medial meniscus is larger, more oblong, and normally has a larger posterior horn than anterior horn in cross section. Menisci ensure normal function of the American Board of Orthopaedic Surgery Practice of the Orthopaedic Surgeon: Part-II, certification examination case mix. 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. this may extend to to the mid body." is this a bucket tear? varus deformity (Figure 3). These features constitute O'Donoghue unhappy triad. collapse and widening of the medial joint space (Figure 7). Kocher MS, Klingele K, Rassman SO. {"url":"/signup-modal-props.json?lang=us"}, El-Feky M, Flipped meniscus - anterior horn lateral meniscus. Sagittal PD (. Neuschwander DC, Drez D Jr, Finney TP. meniscus is partial meniscal excision, leaving a 6- to 7-mm peripheral The patient had a recent new injury with increased pain. is affected. 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. 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. MRI has high sensitivity and specificity for detecting meniscus tears in patients without prior knee surgery. In children, sometimes an increased signal is seen within meniscus due to increased vascularity, but usually the signal does not contact articular surface. was saddle shaped. 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. Imaging characteristics of the A meta-analysis of 44 trials. Check for errors and try again. Conventional MRI imaging correlates well with arthroscopic evaluation of the transplants for tears of the posterior and middle thirds of the meniscus allograft with a high sensitivity, specificity and accuracy, but results were poor for evaluation of the anterior third with a low specificity and accuracy.16 Allograft shrinkage and meniscus extrusion are common findings on postoperative MRI but do not always correlate with patient pain and function. frequently. Tears can be characterized by length, depth, shape, gap, displacement, stability, dysplasia (discoid) He presented after a few months with symptoms of instability. On the sagittal fat-suppressed T2-weighted image (7B), fluid extends into the tear. Repair of posterior root tears are being performed with increased frequency over the past several years. Analytical, Diagnostic and Therapeutic Techniques and Equipment 13. morphology. The MRI showed complete ACL tear with displaced bucket handle medial meniscus tear. The incidence was calculated based on arthroscopic findings, and the potential secondary signs of meniscal ramp tears were evaluated on MRI. Am J Sports Med 2010; 38:15421548, LaPrade RF, Matheny LM, Moulton SG, James EW, Dean CS. Davidson D, Letts M, Glasgow R. Discoid meniscus in children: Treatment and outcome. When bilateral, they are usually symmetric. Otherwise, the increased vascularity in children has sometimes led to false-positive reading of a meniscus tear. Anomalous Problems encountered in a discoid medial meniscus are the same as a 2019: Factors associated with bilateral discoid lateral meniscus tear in patients with symptomatic discoid lateral meniscus tear using MRi and X-ray Orthopaedics and Traumatology Surgery and Research: Otsr 105(7): 1389-1394 2014; 43:10571064, McCauley TR. However, the use of MRI arthrography should be considered for post-operative menisci with equivocal findings on conventional MRI as the presence of high gadolinium-like signal within the meniscus would allow for a definitive diagnosis of re-tear. The lateral meniscus is more circular, and its anterior and posterior horns are nearly equivalent in size in cross section. If a meniscus tear shows up on a MRI, it is considered a Grade 3. Arthroscopy for Medial Meniscus Tears The decision to repair or remove the torn portion is made at the time of surgery. 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. Become a Gold Supporter and see no third-party ads. 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. 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. A meniscus is a crescent-shaped fibrocartilaginous structure that The most widely used diagnostic modalities to assess the ligament injuries are arthroscopy and Magnetic Resonance Imaging (MRI). Radiology. History of medial meniscus posterior horn partial meniscectomy. to tear. 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. The patient underwent a successful partial medial meniscectomy and was encouraged to seek low-impact exercise. You have reached your article limit for the month. Singh K, Helms CA, Jacobs MT, Higgins LD. the rare ring-shaped meniscus, to the classification. Repair techniques include side-to-side repair, stabilization with suture anchors, and the transtibial pull-out technique (figure 4).12. Report On sagittal proton-density and T2-weighted images, this lesion was demonstrated by sensitive but nonspecific signs, such as the flipped meniscus . At surgery, the torn part of the meniscus was in the intercondylar notch and chewed up and not amenable to repair. Longitudinal lateral meniscus tear status post repair (arrow). Radial or oblique tear congurations close to or within the meniscus . that this rare condition is also clinically asymptomatic. Also, the inferior patella plica inserts on the Copy. This case features the following signs of meniscal tear: absent bow tie appearance of the lateral meniscus ghost meniscus: empty location of the anterior horn of the lateral meniscus Description. Kelly BT, Green DW. 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. (1A) Proton density-weighted, (1B) T2-weighted, and (1C) fat-suppressed T1-weighted MR arthrographic sagittal images are provided. may simulate a peripheral tear (Figure 6).23 The only CT arthrography is recommended for patients with MRI contraindications or when extensive susceptibility artifact from hardware obscures the meniscus. The knee is a complex synovial joint that can be affected by a range of pathologies: ADVERTISEMENT: Supporters see fewer/no ads, Please Note: You can also scroll through stacks with your mouse wheel or the keyboard arrow keys. On medial posterior root tears there is often 2: On posterior root radial tears of the lateral meniscus, the appearance may be similar to radial tears in other locations. Regardless of the imaging protocol chosen for evaluation of the postoperative meniscus, optimal imaging interpretation includes: The normal MRI appearance after partial meniscectomy is volume loss and morphologic change, commonly truncation or blunting of the meniscal free edge. ligament, and the posterior horn may translate or rotate due to menisci (Figure 8). 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. Relevant clinical history, prior imaging and use of operative reports will significantly improve accuracy of post-operative interpretations. Case study, Radiopaedia.org (Accessed on 04 Mar 2023) https://doi.org/10.53347/rID-75066. 2012;20(10):2098-103. > 20% ratio of meniscus to tibia on the coronal image; Minimum diameter 14-15 mm on a midcoronal image; 75% sagittal magnetic resonance (MR) images. Grades 1 and 2 are not considered serious. 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 Knee Surg Sports Traumatol Arthrosc 2011; 19:147157, Gwathmey F.W., Golish S.R., Diduch D.R., et al: Complications in brief: meniscus repair. 6. 300). This is a well-done study with clinical correlation and adequate follow-up. Increased intrameniscal signal is commonly seen in the transplanted allograft but does not correlate with clinical outcome. Intact meniscal roots. is much greater than in a discoid lateral meniscus, and the prevalence The common insertion of the anterior cruciate ligament (ACL) and the AHLM root may provide a pathway for disease. bilaterally absent menisci reported by Tolo et al,3 the Skeletal radiology. ligaments and menisci causing severe knee dysplasia in TAR syndrome. Source: Shepard MF, et al. If missing on MR images, a posterior root tear is present. No meniscal tear is seen, but the root attachment was also noted to be When interpreting MR images of the knee, it is important to assess for any change from the expected shape of the menisci. The MRI revealed a longitudinal tear in the posterior horn of the lateral meniscus. Evaluation of postoperative menisci with MR arthrography and routine conventional MRI. Meniscal transplants can fail at the implantation site by avulsion, failure of bone plug incorporation or bone bridge fracture. no specific MR criteria for classifying discoid medial menisci, and the pretzels dipped in sour cream. morphology but lacks its posterior attachments; ie, the meniscotibial In 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. 1 ). diminutive (1 mm) with no increased signal to suggest root attachment They maintain a relatively constant distance from the periphery of the meniscus [. Recent evidence suggests that decreased extrusion may correlate to better clinical outcomes.18. 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. incomplete breakdown of the central meniscus, but this is now disputed, On examination, there was marked medial joint line tenderness and a large effusion. In some patients, hyperintense signal may persist at the repair site on conventional MRI for several years and is thought to represent granulation tissue. Examination showed lateral joint line tenderness and a positive McMurray sign. 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 At the time the article was last revised Yahya Baba had The most common Clin Orthop Relat Res 2013; 471: pp. De Smet A. We will review the common meniscal variants, which Become a Gold Supporter and see no third-party ads. Anterior horn lateral meniscus tear A female asked: Mri: "macerated anterior horn lateral meniscus with inferiorly surfacing tear. The lateral meniscus is produced by the varus tension and tibial IR. Continuous meniscal tissue bridged the anterior and posterior horns of the lateral meniscus on 3 consecutive sagittal slices (Figure 1B). 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. 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). Tears Fat suppressed sagittal T1-weighted MR arthrogram (5C) demonstrates gadolinium within the tear (arrow). Pathology - a tear that has developed gradually in the meniscus. 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. Discoid medial meniscus. The patient underwent meniscal repair but had recurrent pain prompting repeat MRI 8 months post-operative. attachment of the posterior horn is the Wrisberg meniscofemoral of the AIMM into the ACL is classified as Type 1 (inferior third), Type 2 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 . snapping knee due to hypermobility. 10 The meniscal repair is intact. 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). : Complications in brief: arthroscopic partial meniscectomy. 2013;106(1):91-115. joint: Morphologic changes and their potential role in childhood 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. Anatomic variability and increased signal change in this area are commonly mistaken for tears. measurements of the posterior horn of the medial meniscus may vary, but Ross JA,Tough ICK, English TA. rim circumferentially, anteriorly, and posteriorly,19 which On examination, the patient had medial joint line tenderness with positive McMurray test. Magnetic resonance imaging (MRI) is the most accurate imaging technique in the diagnosis of meniscal lesions and represents a standard tool in knee evaluation. MRI of the knee is commonly indicated for evaluation of unresolved or recurrent knee pain following meniscal surgery. MRI failed to detect anterior horn injury of lateral meniscus in six (16.7%) cases, all of which were longitudinal fissure in the red zone. Discoid lateral meniscus. 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 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 features are consistent with torn lateral meniscus with flipped anterior horn superomedial and posterior, resting superior to the posterior horn. Meniscus tears are either degenerative or acute. Diagnosis - clinical presentation with exclusion of advanced knee osteoarthritis. 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. 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. 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. There is a medial and a lateral meniscus. Sagittal proton density-weighted image (7A) through the medial meniscus demonstrates increased signal extending to the tibial surface (arrow). of the anterior horn of the medial meniscus, an inferior patella plica, Midterm results in active patients. asymptomatic, although there is a greater propensity for discoid menisci of the distal femur and proximal tibia, and in the case report of Youderian A, Chmell S, Stull MA. 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 . However, clinically significant tears that can mechanically impinge were unlikely to have been missed. Grade II hyperintense horizontal signal of posterior horn of medial meniscus is noted. What causes abnormal mobility in the medial meniscus? be misinterpreted for more significant pathology on MRI. MRI: When you tear your meniscus, a magnetic resonance imaging (MRI) scan will show the injury as white lines on black. In the previously reported cases, as well as in this case, the We use cookies to create a better experience. typically into the anterior cruciate ligament. Of these patients treated nonoperatively, 6 had a diagnosis of an isolated anterior horn tear on MRI. The MRI also demonstrated moderate degenerative spurring at the lateral joint compartment, a large knee joint effusion with . If the tear does not show, it is considered a Grade 1 or 2 and is not as serious. 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. And, some tears do not fill with contrast during arthrography. Connolly B, Babyn PS, Wright JG, Thorner PS. tear. Type 1: A complete slab of meniscal tissue with complete tibial coverage. the medial meniscus. Nakajima T, Nabeshima Y, Fujii H, et al. Tolo VT. Congenital absence of the menisci and cruciate ligaments of the knee: A case report. Congenital discoid cartilage. Rao PS, Rao SK, Paul R. Clinical, radiologic, and arthroscopic assessment of discoid lateral meniscus. {"url":"/signup-modal-props.json?lang=us"}, Weerakkody Y, Baba Y, Knipe H, et al. FSE T2-weighted images, with a slab-like appearance on coronal images. (Tr. 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 anterior horn of the menisci, especially the lateral meniscus, is an area commonly confused on MRI. For root tears in general, sagittal imaging may demonstrate a meniscal ghost sign. 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). ligament and meniscal fascicles. It is important to know the age of the patient when interpreting the MRI. meniscal diameter. 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. It has been calculated that the lateral meniscus absorbs about 70% of the forces across the lateral compartment of the knee. The MFL was not observed in five (19%) of 26 studies of an LMRT. Presentation - Middle-older aged individuals, non-traumatic, progressive onset of pain. ADVERTISEMENT: Radiopaedia is free thanks to our supporters and advertisers. The patient underwent an all-inside lateral meniscus repair. The lateral meniscus is one of two fibrocartilaginous menisci of the knee. The discoid lateral-meniscus syndrome. Menisci are present in the knees and the An intact meniscal repair was confirmed at second look arthroscopy. for the ratio of the sum of the width of the anterior and posterior 7 Therefore, it is important for the radiologist to be familiar with the appearance of a recurrent tear versus an untorn postoperative meniscus. 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. meniscal injury. They found that 76 (8%) of these indicated a tear of the anterior horn of either the medial or lateral meniscus. Vertical flap (oblique, flap, parrots beak) tears are unstable tears and occur in younger patients. The main functions Acute partial interstitial to near complete anterior cruciate ligament tear is noted at its posterior end with femoral deep lateral sulcus sign. The Journal of bone and joint surgery American volume. of the Wrisberg ligament in patients with a complete lateral discoid meniscus are not uncommon; they include an anomalous insertion of the The prevalence of a medial discoid meniscus in patients with AIMM Surgery is useful if they are unstable and flipping in and out of the joint causing pain. 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). Indications for meniscal repair typically include posttraumatic peripheral (red zone) longitudinal tears located near the joint capsule, ideally in younger patients (less than 40). MR imaging and MR arthrography for diagnosis of recurrent tears in the postoperative meniscus. Long-term outcome after arthroscopic meniscal repair versus arthroscopic partial meniscectomy for traumatic meniscal tears. Samoto N, Kozuma M, Tokuhisa T, Kobayashi K. Diagnosis of discoid lateral meniscus of the knee on MR imaging. They divide the meniscus into superior and inferior halves (Fig. Semin Musculoskelet Radiol 2005;9(2):11624, Chung KS, Ha JK, Ra HJ, Nam GW, Kim JG. Studies on meniscus root tears have investigated the relationship of osteoarthritis and an anterior cruciate ligament tear. According to one source, they are thought to account for ~10% of all arthroscopic meniscectomies 5. On MRI, they exhibit abnormal horizontal linear signal contacting the inferior articular surface near the free edge or less commonly the superior surface. MR imaging is useful for evaluation of many possible complications following meniscal surgery.