is affected. It has been calculated that the lateral meniscus absorbs about 70% of the forces across the lateral compartment of the knee. 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. AJR Am J Roentgenol 2009;193:515-523. 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). A 23-year-old female presented with a 2-month history of catching and pain in the knee when arising from a squatting position. Get unlimited access to our full publication and article library. Anterior horn lateral meniscus tear A female asked: Mri: "macerated anterior horn lateral meniscus with inferiorly surfacing tear. Anterior tibial marrow edema and organized trabecular fracture measuring 16 mm AP, 18 mm transverse. As a result, the accuracy rate of diagnosis by MRI is 83.3%. The lateral . 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. Discoid meniscus in children: Magnetic resonance imaging characteristics. 5 In the first instance, tears of the lateral aspect of the anterior horn of the medial meniscus are extremely uncommon and should not be a diagnostic Meniscus tears are either degenerative or acute. Diagnostic performance is decreased following partial meniscectomy since the standard criteria used to diagnose a meniscus tear cannot be applied to the post-operative meniscus.3,4,5,6 Partial meniscectomy may distort the normal morphology of the meniscus and increased meniscal signal intensity may extend to the articular surface when a portion of the meniscus has been resected, simulating a tear. 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. posterior fascicles and meniscotibial ligament are absent and a high Renew or update your current subscription to Applied Radiology. Radiology. Examination showed lateral joint line tenderness and a positive McMurray sign. to tear. to the base of the ACL or the intercondylar notch. Comparison of Postoperative Antibiotic Regimens for Complex Appendicitis: Is Two Days as Good as Five Days? The lateral meniscus is more circular, and its anterior and posterior horns are nearly equivalent in size in cross section. Zonal variation is also seen in the density of meniscus cells and their phenotypes with a chondrocytic inner zone and fibroblastic outer zone. Root tears are often large radial tears that extend through the entire AP width of the meniscus. medial meniscus, and not be confined to the ACL as seen in an ACL tear. 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. : Complications in brief: arthroscopic partial meniscectomy. (1A) Proton density-weighted, (1B) T2-weighted, and (1C) fat-suppressed T1-weighted MR arthrographic sagittal images are provided. On this page: Article: Epidemiology Pathology Radiographic features History and etymology for the ratio of the sum of the width of the anterior and posterior It is believed that discoid CT arthrography is a recommended alternative for patients who are not MR eligible. The lateral meniscus is produced by the varus tension and tibial IR. The superior, middle and inferior geniculate arteries are the main vascular supply to the menisci. Tears Semin Musculoskelet Radiol 2005;9(2):11624, Chung KS, Ha JK, Ra HJ, Nam GW, Kim JG. of a case of discoid medial cartilage, with an embryological note. Radiographs are usually not diagnostic, but they may show a While this test will show a tear up to 90% of the time, it does not always. There Pinar H, Akseki D, Karaoglan O, et al. Radiology. This is a well-done study with clinical correlation and adequate follow-up. When bilateral, they are usually symmetric. On the sagittal proton density-weighted image (11A), signal contacts the tibial surface. The post arthrogram view (13B) reveals gadolinium within the repair site. Again, this emphasizes the importance of accurate history, prior imaging and operative reports. Type 1 is most common, and type Sagittal proton density-weighted (14A) and coronal T1-weighted (14B) images reveal a recurrent bucket-handle tear through the original repair site with typical findings of a displaced meniscal flap (arrow) into the intercondylar notch. of the anterior horn of the medial meniscus, an inferior patella plica, The incidence of lateral meniscus posterior root tears was approximately 4 times higher than of medial meniscus posterior root tears in both primary (12.2% vs 3.2%) and revision (20.5% vs 5.6%) ACLRs. However, many clinicians opt to use conventional MRI as the initial postoperative imaging study and reserve MR arthrography for equivocal cases. Am J Sports Med 2016; 44:625632, De Smet AA, Horak DM, Davis KW, Choi JJ. That reported case was also associated with These tears are usually degenerative in nature and usually not associated with a discrete injury [. The sutures are tied over a cortical fixation device or Endobutton (short arrow) with the knee flexed at 90 to secure the root repair. MRI plays a critical role in influencing the treatment decision and enables information that would obviate unnecessary surgery including diagnostic arthroscopy. 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. Sagittal proton density-weighted image (9A) demonstrates no high signal abnormality. described in thrombocytopenia absent radius syndrome (TAR syndrome).2,3 Bilateral hypoplasia of the medial meniscus has also been reported.4. the posterior horn is usually much larger than the anterior horn (the A tear of the lateral meniscus can occur from a sudden injury, or from chronic wear and overload. Schwenke M, Singh M, Chow B Anterior Cruciate Ligament and Meniscal Tears: A Multi-modality Review. On examination, the patient had medial joint line tenderness with positive McMurray test. tissue only persists at the edges, where differentiation into the FSE T2-weighted images, with a slab-like appearance on coronal images. For DSR inquiries or complaints, please reach out to Wes Vaux, Data Privacy Officer, The patient underwent partial medial meniscectomy and ACL reconstruction. 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 [ 8, 11, 12 ]. Meniscal transplant is usually reserved for patients younger than 50 years who have normal axial alignment. variant, and discoid medial meniscus. Of these 45 patients, there was an average of 3.74 additional pathological conditions noted on the MRI scan, mainly including degenerative arthrosis or patellar chondromalacia to explain the patients continued pain. The Wrisberg variant may present with a The tear was treated by partial meniscectomy at second surgery. 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. Seventy-four cases of bucket-handle tears (mean age, 27.2 11.3 years; 38 medial meniscus and 36 lateral meniscus; 39 concomitant anterior cruciate ligament (ACL) reconstruction) were treated with arthroscopic repair from June 2011 to August 2021. Check for errors and try again. be misinterpreted for more significant pathology on MRI. The patient underwent an all-inside lateral meniscus repair. measurements of the posterior horn of the medial meniscus may vary, but 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). small meniscus is also seen in the wrist joint. They often tend to be radial tears extending into the meniscal root. The insertion site 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. Type Brody J, Lin H, Hulstyn M, Tung G. Lateral Meniscus Root Tear and Meniscus Extrusion with Anterior Cruciate Ligament Tear. Menisci are present in the knees and the This high rate of success, however, may not apply to anterior horn tears, which occur much less commonly than posterior horn and meniscal body tears. Best assessed on T2 weighted sequences. Learn more. Am J Sports Med 2017; 45:884891, Zaffagnini S, Grassi A, Marcheggiani Muccioli GM, et al. As visualized on sagittal MR images, the anterior horn of the medial meniscus is shorter than the posterior horn, whereas the anterior and posterior horns of the lateral meniscus are of equal length. 1). Heron, D, Bonnard C, Moraine C,Toutain A. Agenesis of cruciate One important reason for such discrepancies is a failure to understand the transverse geniculate ligament of the knee (TGL). Anatomic variability and increased signal change in this area are commonly mistaken for tears. Posterior meniscal root repairs: outcomes of an anatomic transtibial pull-out technique. History of longitudinal medial meniscus tear managed by meniscal repair (arrows). 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. Findings indicate an intact meniscus following partial meniscectomy with normal intrameniscal signal. MRIs of BHT may have several characteristic appearances including (1) fragment in the notch sign; (2) double anterior horn sign, in which there is an additional meniscal fragment in the anterior joint on top of the native anterior horn; (3) the absent bow tie sign; (4) the double PCL sign, in which the centrally displaced fragment lies just anterior and parallel to the PCL giving the appearance of two PCLs; and (5) the coronal truncation sign, in which the free edge of the meniscal body appears clipped off on coronal images (Fig. Knee Surg Sports Traumatol Arthrosc. Of these patients treated nonoperatively, 6 had a diagnosis of an isolated anterior horn tear on MRI. Objectives: Low-field MRI at 0.55 Tesla (T) with deep learning image reconstruction has recently become commercially available. 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. The same imaging criteria (as for the case of greater than 25% partial meniscectomy), the presence of fluid signal on T2-weighted or contrast extending into the meniscal substance is used to diagnose a recurrent tear. The anterior horn of the menisci, especially the lateral meniscus, is an area commonly confused on MRI. An intact meniscal repair was confirmed at second look arthroscopy. 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. Development of the menisci of the human knee Stein T, Mehling AP, Welsch F, von EisenhartRothe R, Jger A. Normal course and intensity of both cruciate ligaments. Of the 54 participants, 5 had PHLM tears and 49 were normal. Horizontal (degenerative) tears run relatively parallel the tibial plateau. Longitudinal lateral meniscus tear status post repair (arrow). It is usually seen near the lateral meniscus central attachment site. morphology. 6 months post-operative she had increased pain prompting follow-up MRI. Davidson D, Letts M, Glasgow R. Discoid meniscus in children: Treatment and outcome. hypermobility. Meniscal root tears are a form of radial tear that involves the central attachment of the meniscus (12a). On MRI, longitudinal tears appear as a vertical line of abnormal signal contacting articular surface. The avulsed anterior horn of the lateral meniscus is flipped over and situated above the posterior horn. In this case, we can determine that there is a new tear in a different location. reported.4. (Figure 1). 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 This has also been described as grade 2 signal [, Sagittal fat-suppressed T2 image of a 14-year-old patient showing a grade 2 signal in the posterior horn of the medial meniscus (PHMM). These features constitute O'Donoghue unhappy triad. 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. 800-688-2421. No meniscal tear is seen, but the root attachment was also noted to be Kijowski et al. The lateral meniscus is more circular with a shorter radius, covering 70% of the articular surface with the anterior and posterior horns approximately the same size. The example above demonstrates the importance of baseline MRI comparison when evaluating the postoperative meniscus. Both ligaments attach distally to the posterior horn of the lateral meniscus and contribute to posterior drawer stability . We hope you found our articles Thompson WO, Thaete FL, Fu FH, Dye SF. the example shown (Figures 1 and 2), the entire medial meniscus is To assess the prevalence of meniscal extrusion and its . Thirty-one of these patients underwent subsequent arthroscopic evaluation to allow clinical correlation. 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). 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. It splits into two bands at the PCL, named Humphry(anterior to the PCL) and Wrisberg (posterior to the PCL). 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 and the frequency of meniscal tears. Figure 7: Meniscofemoral ligament. 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 Congenital absence of the meniscus is extremely rare and has been documented in TAR syndrome and in isolated case reports.2,3 There is no universally accepted system for classifying meniscal tear patterns. RESULTS. 2013;106(1):91-115. Illustration of the transtibial pullout repair for a tear of the posterior horn medial meniscal root (arrow). joint, and they also protect the hyaline cartilage. When interpreting MR images of the knee, it is important to assess for any change from the expected shape of the menisci. 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. Type 1: A complete slab of meniscal tissue with complete tibial coverage. Bilateral complete discoid medial menisci combined with anomalous insertion and cyst formation. History of a longitudinal medial meniscus tear managed by repair and concurrent ACL reconstruction. 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. There is no telling how much this error rate will change for radiologists less experienced with MRI. In these cases, MR arthrography may provide additional diagnostic utility. horn of the lateral meniscus, and oblique tear orientation In the present study, the patients analyzed came from the have been the most difficult for imaging planes to visualize same geographical area . In the above case there is no gross chondral defect although the articular cartilage is noticeably thinner compared to the baseline study despite the patients young age. Associated anomalies in a discoid medial Br Med Bull. Total meniscectomy is rarely performed unless the meniscus is so severely damaged that no salvageable meniscal tissue remains. Unable to process the form. MRI Findings: Medial meniscus: Tear of the posterior horn seen to the inferior articular surface continuing into the posterior body and becoming more vertical. slab-like configuration on sagittal MR images, with > 3 bowties joint: Morphologic changes and their potential role in childhood 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. 2006; 88:660667, Boutin RD, Fritz RC, Marder RA. 10 70 year-old female with history of medial meniscus posterior horn radial tear. Shepard et al conclude that with a 74% false-positive rate, anterior horn tears should be treated surgically only if clinical correlation exists. They often tend to be radial tears extending into the meniscal root. Radiology. does not normally occur.13. partly divides a joint cavity, unlike articular discs, which completely Sagittal T2-weighted image (10B) reveals no fluid at the repair site. diagnostic dilemma, as the AIMM band will be seen to extend to the meniscal diameter. Tears in the red zone have the potential to heal and are more amenable to repair. 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 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. In children, sometimes an increased signal is seen within meniscus due to increased vascularity, but usually the signal does not contact articular surface. Check for errors and try again. The clinical significance of anterior horn meniscal tears diagnosed on magnetic resonance images. The examiner can test the entire posterior horn up to the middle segment of the meniscus using the IR of the tibia followed by an extension. He presented after a few months with symptoms of instability. posterior horn of the medial meniscus include a triangular hypointense Biologic augmentation with application of exogenous fibrin clot or growth factors may be combined with the repair to promote healing. Considered a feature of knee osteoarthritis. Healed peripheral medial meniscus posterior horn repair and new longitudinal tear in a different location. Intact meniscal roots. Tolo VT. Congenital absence of the menisci and cruciate ligaments of the knee: A case report. CT arthrography is recommended for patients with MRI contraindications or when extensive susceptibility artifact from hardware obscures the meniscus. collapse and widening of the medial joint space (Figure 7). The medial meniscus is more tightly anchored than the lateral meniscus, allowing for approximately 5mm of anterior-posterior translation. This patient had relief after the initial repair surgery, then had a second injury with recurrent symptoms, which is why the surgeon felt this was a recurrent tear. MR arthrogram fat-suppressed sagittal T1-weighted image (11C) shows no gadolinium in the repair. Wrisberg variant, the morphology of the meniscus may be normal, but the There is a medial and a lateral meniscus. 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. 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 . 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. 6. 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 horns to the meniscal diameter on a sagittal slice that shows a maximum Radial or oblique tear congurations close to or within the meniscus . MR criteria are used to make the diagnosis. 1. 2014; 43:10571064, McCauley TR. normal knee. 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 rare ring-shaped meniscus, to the classification. The patient failed conservative management of aspiration and cortisone injection. 2002; 222:421429, Ciliz D, Ciliz A, Elverici E, Sakman B, Yuksel E, Akbulut O. 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. . Illustration of the medial and lateral menisci. Radiographs may Kim SJ, Moon SH, Shin SJ. Most lateral meniscal tears are due to twisting or turning activities or falls. Thirty-one of these patients underwent subsequent arthroscopic evaluation to allow clinical correlation. Extrusion is commonly seen following root repair. Meniscal root tears are defined as radial tears located within 1 cm from the meniscal attachment or a bony rootavulsion. 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. posterior horn usually measures 12 mm to 16 mm in the sagittal plane in Kim SJ, Choi CH. The self-reported complication rate for partial meniscectomy is 2.8% and meniscus repair is 7.6%. After preparing the recipient knee by creating a matching keyhole trough in the tibia, the surgeon slides the allograft bone plug into its matching tibial slot and sutures the periphery of the allograft meniscus to the capsule. Relevant clinical history, prior imaging and use of operative reports will significantly improve accuracy of post-operative interpretations. A preliminary report, Principles and decision making in meniscal surgery, The Anterior Meniscofemoral Ligament of the Medial Meniscus, Accurate patient history including site and duration of symptoms, Garrett WE Jr, Swiontkowski MF, Weinstein JN, et al. Tears of the anterior horn of the medial meniscus, an inferior patella plica, and ACL tears can be mistaken for AIMM, but carefully tracing the ligament will help to exclude these conditions. pretzels dipped in sour cream. After failing conservative management with NSAIDs, PT, and activity modification, he underwent an MRI. 1427-143. Figure 8: Medial oblique menisco-meniscal . Evaluation of postoperative menisci with MR arthrography and routine conventional MRI. This mesenchymal Disadvantages include risks associated with joint injection, radiation exposure and lower contrast resolution compared to MRI, particularly in the extraarticular soft tissues. include hypoplastic menisci, absent menisci, anomalous insertion of the Is sport activity possible after arthroscopic meniscal allograft transplantation? problem in practice. The example above illustrates marked degenerative changes caused by loss of meniscal function. 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. Create a new print or digital subscription to Applied Radiology. Description. Otherwise, the increased vascularity in children has sometimes led to false-positive reading of a meniscus tear. The meniscus root plays an essential role in maintaining the circumferential hoop tension and preventing meniscal displacement. It can be divided into five segments: anterior horn, anterior, middle and posterior segments, and posterior horn. 4. are reported cases of complete absence of the medial meniscus as 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. However, clinically significant tears that can mechanically impinge were unlikely to have been missed. They are most frequently seen at the posterior horn of the medial meniscus. show cupping of the medial tibial plateau, proximal medial tibial physis AJR Am J Roentgenol. The condition is typically asymptomatic and, therefore, is infrequently diagnosed.14 Most patients are asymptomatic, but injury to the meniscus can On sagittal proton-density and T2-weighted images, this lesion was demonstrated by sensitive but nonspecific signs, such as the flipped meniscus . The articular cartilage is well seen on the pre-operative sagittal proton density-weighted image (19B). 3: The Wrisberg variant, where the meniscus may have a normal mimicking an anterior horn tear. Because this is a relatively new procedure, few studies have been dedicated to MRI evaluation of postoperative root repair.
St Luke's Hospital Residency Programs,
7 Eleven Policies And Procedures,
Articles A
anterior horn lateral meniscus tear: mri