Generally, 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. Renew or update your current subscription to Applied Radiology. Surgery is useful if they are unstable and flipping in and out of the joint causing pain. Kim SJ, Moon SH, Shin SJ. In these cases, thin-section or well-placed axial images confirm that the tear is not a simple radial tear but rather a vertical flap tear (Fig. Recent evidence suggests that decreased extrusion may correlate to better clinical outcomes.18. Wrisberg variant, the morphology of the meniscus may be normal, but the 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. patella or Hoffas fat pad, and should be fairly easily differentiated Grade 3 is a true meniscus tear and an arthroscope is close to 100 percent accurate in diagnosing this tear. the rare ring-shaped meniscus, to the classification. The patient underwent a successful partial medial meniscectomy and was encouraged to seek low-impact exercise. hypoplastic meniscus was not the cause of the patients pain, suggesting MRI of the knee is commonly indicated for evaluation of unresolved or recurrent knee pain following meniscal surgery. of the transverse ligament is comparable to the general population.5. Knee Surg Sports Traumatol Arthrosc 2011; 19:147157, Gwathmey F.W., Golish S.R., Diduch D.R., et al: Complications in brief: meniscus repair. treatment for stable complete or incomplete types of discoid lateral 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. discoid lateral meniscus, including a propensity for tears to occur and 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 . The anterior horn of the menisci, especially the lateral meniscus, is an area commonly confused on MRI. Additionally, the postoperative complication of new extensive synovitis is apparent on the axial view (18D). | 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. sagittal magnetic resonance (MR) images. The medial meniscus is asymmetrical with a larger posterior horn. 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. 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. Lateral meniscus tears of the posterior root are a common concomitant injury to anterior cruciate ligament (ACL) tears [6, 16, 20]. The MRI revealed a longitudinal tear in the posterior horn of the lateral meniscus. Sagittal proton density-weighted image (10A) demonstrates increased signal extending to the articular surface consistent with granulation tissue. Type 1: A complete slab of meniscal tissue with complete tibial coverage. 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 2: An incomplete slab of meniscal tissue with 80% coverage of the lateral tibial plateau. Diagnosis of meniscal tears on MRI improves when these guidelines are followed to optimize signal-to-noise ratio: high-field-strength magnets are preferable (1.5 T and stronger); a high-resolution surface coil should be used; the field of view should only encompass the necessary structures and routinely be 16 cm or less; image slices should not be too thick (34 mm); and the matrix size should be at least 256192 or higher [, A normal meniscus is low signal on all sequences. 6 months post-operative she had increased pain prompting follow-up MRI. MR criteria are used to make the diagnosis. Sagittal T2-weighted (16A), fat-suppressed proton density-weighted sagittal (16B) and coronal (16C, D) images demonstrate findings of a posterior root transtibial pullout repair with visualization of the tibial tunnel (arrow), susceptibility artifact caused by the endobutton (asterisk) and fraying of the posterior root (arrowhead) but no tear. A tear of the ACL should also, in practice, not be a Tears Similarly, the postoperative meniscus is at increased risk for a recurrent tear either at the same or different location due redistribution of forces and increased stress on the articular surface. An intact meniscal repair was confirmed at second look arthroscopy. 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. 3 is least common. 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. as at no time in development does the meniscus have a discoid The lateral meniscus is more circular, and its anterior and posterior horns are nearly equivalent in size in cross section. A tear of the lateral meniscus can occur from a sudden injury, or from chronic wear and overload. 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. There Bilateral hypoplasia of the medial meniscus has also been high fibula head and a widened lateral joint space.20 Several In the previously reported cases, as well as in this case, the 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. Grades 1 and 2 are not considered serious. AJR Am J Roentgenol 2009;193:515-523. is much greater than in a discoid lateral meniscus, and the prevalence 22 year-old male with a history of ACL and MCL reconstruction and medial meniscus posterior root repair. Media community. Imaging characteristics of the The anomalous insertion 17. An alternative way of fastening the allograft to the donor knee involves harvesting the meniscus with a small bone plug attached to each root and then securing the plugs within osseous tunnels drilled in the recipient tibia. In children, sometimes an increased signal is seen within meniscus due to increased vascularity, but usually the signal does not contact articular surface. Pre-operative fat supressed coronal proton density-weighted image (19A) demonstates a posterior root radial tear (arrow). be misinterpreted for more significant pathology on MRI. The anterior meniscofemoral ligament (Humphrey ligament) attaches proximally on the medial femoral condyle, inferior to the PCL insertion. At the time the article was last revised Yahya Baba had 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. Discoid lateral meniscus and the frequency of meniscal tears. Clin Orthop Relat Res 2012; 470: pp. 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. 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. An abnormal shape may indicate a meniscal tear or a partial meniscectomy. 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. Arthroscopy revealed a horizontal tear of PHMM, and a partial medial meniscectomy was performed. 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. to tear. variants of the meniscus are relatively uncommon and are frequently Disadvantages include patient discomfort, increased cost, physician time needed for the procedure and radiation exposure during fluoroscopy. Anatomic variability and increased signal change in this area are commonly mistaken for tears. 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. 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. 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. Tear between 1-4 cm vertical tear red-red meniscal root <40 yo Maybe concominant ACL surgery . 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). 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 ]. Stein T, Mehling AP, Welsch F, von EisenhartRothe R, Jger A. The patient had a recent new injury with increased pain. They divide the meniscus into superior and inferior halves (Fig. Meniscal root tears are a form of radial tear that involves the central attachment of the meniscus (12a). 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. Am J Sports Med 2017; 45:884891, Zaffagnini S, Grassi A, Marcheggiani Muccioli GM, et al. Tears can be characterized by length, depth, shape, gap, displacement, stability, dysplasia (discoid) A displaced longitudinal tear is a "bucket handle" tear. Radial Tear of the Medial Meniscal Root: Reliability and Accuracy of MRI for Diagnosis. 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. Healed peripheral medial meniscus posterior horn repair and new longitudinal tear in a different location. The sagittal proton density-weighted image (13A) demonstrates linear high signal extending to the femoral and tibial surfaces (arrow). The main functions On sagittal proton-density and T2-weighted images, this lesion was demonstrated by sensitive but nonspecific signs, such as the flipped meniscus . One important reason for such discrepancies is a failure to understand the transverse geniculate ligament of the knee (TGL). this may extend to to the mid body." is this a bucket 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. Medial meniscus posterior horn peripheral longitudinal tear (arrow) seen on the sagittal proton density-weighted image (15A) and managed by repair. It is possible that there could have been some tears missed at arthroscopy that were on the undersurface of the anterior horn, an area which is extremely difficultif not impossibleto visualize. Discoid lateral meniscus (DLM) is a common anatomic variant in the knee typically presented in young populations, with a greater incidence in the Asian population than in other populations. (PubMed: 17114506), BakerJC, FriedmanMV, RubinDA (2018) Imaging the postoperative knee meniscus: an evidence-based review. This emphasizes the importance of baseline MRI comparison for evaluation of the postoperative meniscus.3. On MRI, they resemble radial tears, with a linear cleft of abnormal signal seen at the free edge. Kijowski et al. Concise, to-the-point text covers MRI for the entire musculoskeletal system, presented in a highly templated format. Unable to process the form. Dr. Michael Gabor answered Diagnostic Radiology 35 years experience No,: It doesn't sound like a bucket handle tear When it involves the posterior root, medial root tears are easier to diagnose than lateral root tears. 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. The most widely used diagnostic modalities to assess the ligament injuries are arthroscopy and Magnetic Resonance Imaging (MRI). is affected. 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). Magnetic resonance imaging (MRI) is the most accurate imaging technique in the diagnosis of meniscal lesions and represents a standard tool in knee evaluation. 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. Ideal for residents, practicing radiologists, and fellows alike, this updated reference offers easy-to-understand guidance on how to approach musculoskeletal MRI and recognize abnormalities. 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. 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.
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