Anterior cruciate ligament tears: MR imaging-based diagnosis in a pediatric population

PURPOSE: To evaluate the diagnostic accuracy of primary and secondary magnetic resonance (MR) imaging findings of anterior cruciate ligament (ACL) tears in young patients with immature skeletal systems. MATERIALS AND METHODS: MR images obtained in 43 patients aged 5-16 years who underwent arthroscopy were retrospectively reviewed. Two reviewers evaluated primary findings (abnormal signal intensity, abnormal course as defined by Blumensaat angle, and discontinuity), secondary findings (bone bruise in lateral compartment, anterior tibial displacement, uncovering of posterior horn of lateral meniscus, posterior cruciate ligament line, and posterior cruciate angle), and meniscal and other ligamentous injuries. RESULTS: There were 19 ACL tears and 24 intact ACLs. Overall sensitivity and specificity of MR imaging in detecting ACL tears were 95% and 88%, respectively. Sensitivities of the primary findings were 94% for abnormal Blumensaat angle; 79%, abnormal signal intensity; and 21% discontinuity. The specificity of all primary findings was 88% or greater. The sensitivity and specificity of the secondary findings, respectively, were 68% and 88% for bone bruise; 63% and 92%, anterior tibial displacement; 42% and 96%, uncovered posterior horn of lateral meniscus; 68% and 92%, positive posterior cruciate line; and 74% and 71%, abnormal posterior cruciate angle. Fifteen (79%) patients had meniscal tears, and five (26%) had collateral ligament injuries. CONCLUSION: Primary and secondary findings of ACL tears in young patients have high specificity and are useful for diagnosis.     

Relationship between bone bruise volume and the presence of meniscal tears in acute anterior cruciate ligament rupture

Purpose

To determine whether there is a relationship between the size of the bone bruise volume after an acute anterior cruciate ligament (ACL) rupture and the presence of meniscal tears in the medial and lateral compartment.

Methods

Following Institutional Review Board approval, 50 patients with an acute ACL rupture and MRI imaging within 30 days of injury were identified. Two musculoskeletal radiologists evaluated the lateral and medial menisci and graded them as one of the following: no meniscal tear, tear of one meniscus (medial or lateral) or tear of both menisci (medial and lateral). Sagittal T2 fat-suppressed images were used to calculate bone bruise volume. The relationship between bone bruise volume and the presence of a meniscus tear was calculated.

Results

Forty-three (86 %) patients had a bone bruise, 16 (32 %) patients had no tear, 7 (14 %) patients had lateral meniscus tear, 13 (26 %) patients had medial tear and 14 (28 %) patients had medial and lateral tears. There was a statistically significant difference in femoral bone bruise volume when comparing no meniscal tear to medial and lateral tears as well as when comparing medial or lateral tears to medial and lateral tears.

Conclusion

There is a statistically significant relationship between femoral bone bruise volume and the presence of meniscal tears in ACL injury, especially in the setting of medial and lateral pathology.

Level of evidence

Retrospective cohort study, Level III.     

Association of peripheral vertical meniscal tears with anterior cruciate ligament tears

OBJECTIVE: The purpose of this article is to describe a type of meniscal tear seen on magnetic resonance (MR) imaging, the peripheral vertical tear, and to determine the prevalence of anterior cruciate ligament (ACL) tears in knees with this type of meniscal tear compared to knees with other types of meniscal tears. MATERIALS AND METHODS: Following Institutional Review Board approval, a retrospective review of 200 knee MR examinations with imaging diagnoses of 'meniscal tear' was performed to assess the location and morphology of the meniscal tear, and to assess the status of the ACL. RESULTS: Nineteen peripheral vertical meniscal tears were identified in 17 patients, 14 of whom had acute ACL tears, prior ACL reconstruction, or chronic ACL deficiency. Three peripheral vertical tears were seen in the setting of a normal ACL. Of the 183 examinations with other types of meniscal tears, there were 17 cases with acute ACL tears, prior ACL reconstruction, or chronic ACL deficiency. The difference in the prevalence of ACL tear, reconstruction, or deficiency in knees with meniscal tears of the peripheral vertical type (82.4%) compared with the prevalence of ACL tear, reconstruction, or deficiency in knees with other types of meniscal tears (9.3%) was statistically significant (P < 0.001). The calculated specificity of the presence of peripheral vertical tear morphology in detecting an ACL injury in patients with meniscal tears was 98.2%. CONCLUSIONS: Peripheral vertical meniscal tears, particularly when involving the posterior horn, are highly associated with ACL tear, deficiency, or reconstruction. The finding of this type of tear on knee MR imaging should prompt close inspection of the ACL for evidence of acute or chronic injury, and its presence may help make the diagnosis of ACL tear in equivocal cases.     

Meniscal bucket handle tears: a retrospective study of arthroscopy and the relation to MRI

In this study, we aim to evaluate the arthroscopic findings of meniscal bucket handle tears and to correlate them with the proposed MR imaging signs of meniscal bucket handle tears suggested in the literature. Thirty-six patients who had a diagnosis of bucket handle tear in arthroscopy, in either medial or lateral meniscus, were included in our study (32 males and 4 females). Meniscal tears were evaluated in arthroscopy according to Dandys classification. The MRIs were retrospectively analyzed regarding the following findings: absence of bow tie sign, presence of double posterior cruciate ligament (PCL) sign, double anterior horn sign, flipped meniscus sign, disproportional posterior horn sign, and fragment within the intercondylar region. Locked types I and II fragment of medial meniscus and half-length, whole-width and whole length–half-width fragment of lateral meniscus in arthroscopy were basically correlated with fragment within the intercondylar notch and absent bow tie signs in MRI. We did not find the double PCL sign in any of the patients with a lateral meniscal bucket handle tear. The most common signs in MR images of meniscal bucket handle tears were the fragment in the notch sign and the absent bow tie sign. They were observed with equal frequency of 88.8%. The presence of double PCL sign, double anterior horn sign, flipped meniscus sign, disproportional posterior horn sign were less common (41.66, 33, 25, and 27.7%, respectively). We conclude that the presence of at least two of the six MRI signs should be regarded as highly suggestive for bucket handle tears of menisci.     

Medial and lateral meniscal tear patterns in anterior cruciate ligament-deficient knees. A prospective analysis of 575 tears

We used our database to evaluate the locations of meniscal tears associated with anterior cruciate ligament injuries. Five hundred seventy-five meniscal tears were seen in 476 patients. Each tear was categorized prospectively according to the side (medial/lateral), the radial zone of the tear, and the circumferential zone of the tear. The different tear locations were then compared for the medial and lateral menisci and evaluated for statistical significance. We found a nearly equal number of tears on the medial (305) and lateral (270) sides. A significantly greater number of tears on the medial side as compared with the lateral side were posterior (99.4% versus 87.8%) and peripheral (75.4% versus 44.1%). Peripheral posterior horn tears of the medial meniscus were the most common type of tear (230 of 575, 40%) by a statistically significant amount.     

外伤性膝关节前外侧韧带损伤的MR影像特征及相关性分析

目的探讨外伤所致膝关节前外侧韧带损伤病人的MR影像特征,并分析其与前交叉韧带撕裂、外侧半月板撕裂及骨挫伤的相关性,为深入研究前外侧韧带对膝关节稳定性的作用提供可靠依据。方法回顾性分析2016年1月—2017年2月间因外伤进行膝关节MRI检查的320例病人(共321膝)的影像资料。采用美国GE公司生产的Signa HDe 1.5 T MR扫描设备,分别行膝关节斜矢状面T1WI、质子密度加权成像(PDWI)和冠状面、横断面PDWI扫描。根据前外侧韧带的完整性和损伤部位对所有病人进行分类统计。采用独立性卡方检验对前外侧韧带撕裂与前交叉韧带撕裂、外侧半月板撕裂及骨挫伤的相关性进行分析。结果全部病人膝关节MR影像均可显示前外侧韧带,显示率为100%。151/321膝(47.0%;95%CI为41.6%~52.5%)存在前外侧韧带损伤,其中累及胫骨部、股骨部及半月板部的分别为97膝、96膝及65膝。前交叉韧带撕裂158膝,外侧半月板撕裂98膝,股骨外侧髁挫伤58膝,外侧胫骨平台挫伤71膝,分别与前外侧韧带撕裂具有相关性(均P0.001)。结论 MRI检查可以很好地显示前外侧韧带解剖及其损伤情况。膝关节前外侧韧带损伤与前交叉韧带撕裂、外侧半月板撕裂及膝外侧骨挫伤具有相关性。     

Three Tesla MRI for the diagnosis of meniscal and anterior cruciate ligament pathology: a comparison to arthroscopic findings

AIM: To assess the accuracy of 3T magnetic resonance imaging (MRI) in the evaluation of meniscal and anterior cruciate ligament (ACL) injury. MATERIALS AND METHODS: Sixty-one consecutive patients were identified who were referred for evaluation of suspected intra-articular pathology with a 3T MRI and who, subsequently, underwent an arthroscopic procedure of the knee were included for the study. Two musculoskeletal radiologists interpreted the images. The sensitivity, specificity, positive predictive value, and negative predictive value were then calculated for the MRI versus the arthroscopic findings as a reference standard. RESULTS: The sensitivity and specificity for the overall detection of meniscal tears in this study was 84 and 93%, respectively. The results for the medial meniscus separately were 91 and 93% and for the lateral 77 and 93%. The evaluation of ACL integrity was 100% sensitive and specific. The meniscal tear type was correctly identified in 75% of cases and its location in 94%. CONCLUSION: This study demonstrates good results of 3T MRI in the evaluation of the injured knee. Caution should still be given to the interpretation on MRI of a lateral meniscus tear, and it is suggested that the standard diagnostic criteria of high signal reaching the articular surface on two consecutive image sections be adhered to even at these higher field strengths.     

MR imaging of the knee at 0.2 and 1.5 T: correlation with surgery

OBJECTIVE: The purpose of this study was to compare the diagnostic efficacy of low- and high-field-strength MR imagers in the diagnosis of anterior cruciate ligament tears and meniscus tears. SUBJECTS AND METHODS: In 219 patients with suspected internal derangement of the knee, MR imaging at 0.2 and 1.5 T was performed with similar sequences. Only patients with surgically confirmed diagnosis (n = 90) were included in the statistical analysis. Radiologists were unaware of diagnosis and field strength. Sensitivity, specificity, diagnostic accuracy, and inter- and intraobserver variability were determined. RESULTS: There was excellent correlation between the field strengths in accuracy, sensitivity, and specificity for anterior cruciate ligament and meniscus tears. Accuracy for medial meniscus, lateral meniscus, and anterior cruciate ligament tears was 91-93%, 88-90%, and 93-96%, respectively, at 0.2 T and 91-94%, 91-93%, and 97-98%, respectively, at 1.5 T. Inter- and intraobserver variability values showed excellent correlation (kappa > 0.8). CONCLUSION: The level of diagnostic accuracy in anterior cruciate ligament tears and meniscus tears is comparable for low- and high-field-strength MR imagers.     

Pitfalls and limitations of Magnetic Resonance Imaging in bucket-handle tears of knee menisci

PURPOSE: The aim of the present study was to assess the accuracy of magnetic resonance imaging (MRI) in the diagnosis of bucket-handle tears of the knee menisci, determining the sensitivity and specificity of the imaging for each of the signs typical of these tears. MATERIALS AND METHODS: MR examinations of 495 patients suffering from knee traumas were assessed retrospectively. Forty-eight patients had arthroscopically-proven bucket-handle tears of the meniscus. MR examinations were performed using a 0.5-T superconducting magnet, with T1-weighted spin-echo (SE) and gradient-echo (GE) T2*-weighted sequences. Imaging findings used for the diagnosis were: a) double posterior cruciate ligament sign; b) flipped meniscus sign; c) presence of a displaced fragment of the meniscus in the intercondylar notch, visible in coronal and axial images; d) truncated triangular shape of the peripheral non-displaced portion of the meniscus, visible in coronal images. RESULTS: A total of 43 out of 48 bucket-handle tears of the meniscus were correctly diagnosed at MR, thus overall MR accuracy was 98%. In 12 (28%) cases three signs were present simultaneously the double posterior cruciate ligament (sensitivity 28%, specificity 99%, accuracy 93%) + the displaced fragment in the intercondylar notch (sensitivity 69.8%, specificity 98.7%, accuracy 96.2%) + the truncated triangular shape of the peripheral portion of the meniscus (sensitivity 74.4%, specificity 98%, accuracy 96%). In 18 (42%) cases two signs were present together the displaced fragment of the meniscus + the truncated triangular shape of the peripheral portion of the meniscus. In 13 (30%) cases only one sign was presenting two cases the truncated triangular shape of the peripheral portion of the meniscus and in 11 cases the flipped meniscus sign (sensitivity 25.6%, specificity 93.4%, accuracy 87.5%). No statistically significant differences were found comparing the results for tears of the medial meniscus with those for the lateral meniscus. CONCLUSIONS: MR imaging is highly accurate in diagnosing bucket-handle tears of the menisci due to its ability to identify a displaced fragment of the meniscus in the intercondylar notch or flipped over the anterior horn of the meniscus of origin. We speculate that bucket-handle tears not found by MR imaging are cases where the meniscus was displaced after MR examination.     

Healing potential of meniscal tears without repair in knees with anterior cruciate ligament reconstruction

BACKGROUND: Few previous studies have documented the healing potential of meniscal tears that are left to heal without repair. PURPOSE: To determine the healing rates of meniscal tears left without repair in knees with anterior cruciate ligament reconstruction. STUDY DESIGN: Prospective cohort study. METHODS: One hundred and ninety-two knees were evaluated at the time of anterior cruciate ligament reconstruction and repeat arthroscopy. The healing rates of 41 medial and 42 lateral torn menisci without repair were evaluated by the same 2 surgeons in an identical fashion. RESULTS: Of 41 medial torn menisci left without repair, 22 (56%) were considered completely healed, 3 (7%) were incompletely healed, 11 (24%) were unhealed, and 5 (10%) had expanded unhealed lesions. Of 42 lateral torn menisci, 31 (74%) were considered completely healed, 2 (5%) were incompletely healed, 6 (14%) were unhealed, and 3 (7%) had expanded unhealed lesions. The healing rate of a medial meniscal tear was length dependent and not related to reconstructed ligament stability. CONCLUSIONS: Stable meniscal tears at the time of anterior cruciate ligament reconstruction possibly could be left in situ. However, longer medial meniscal tears are thought to require additional stabilizing procedures.     

Effect of chondrocalcinosis on the MR imaging of knee menisci

OBJECTIVE: Our goal was to determine the influence of chondrocalcinosis on MR imaging in the detection of meniscal tears. MATERIALS AND METHODS: A retrospective review was performed of knee MR imaging and arthroscopy records from two university hospitals between 1996 and 1998. Seventy individuals had radiographic evidence of chondrocalcinosis and underwent knee MR imaging. Thirty-seven of these individuals had undergone arthroscopy for further evaluation of their symptoms. MR imaging sensitivity and specificity in the detection of medial and lateral meniscal tears were calculated in these 37 patients who had radiographic evidence of chondrocalcinosis and in a control group of 34 patients who underwent MR imaging and arthroscopy but did not have knee chondrocalcinosis. RESULTS: In the chondrocalcinosis group, MR imaging sensitivity, specificity, and accuracy for meniscal tear were 78%, 71%, and 78%, respectively, for the lateral meniscus, and 89%, 72%, and 81% for the medial meniscus. The control group showed sensitivity, specificity, and accuracy of 93%, 100%, and 97%, respectively, for the lateral meniscus and 100% in all cases for the medial meniscus. The MR imaging detection of meniscal tears in both the lateral and medial compartments combined is significantly poorer in the presence of chondrocalcinosis (p < 0.005). CONCLUSION: MR imaging sensitivity and specificity for detection of meniscal tear is decreased in the presence of meniscal chondrocalcinosis. Chondrocalcinosis appeared as a high-signal-intensity region on T1-weighted, intermediate-weighted, and inversion recovery sequences. The high signal of chondrocalcinosis on inversion recovery sequence is an interesting observation that to our knowledge has not been previously reported. Radiographic correlation with the MR imaging examination can help prevent overdiagnosing meniscal tears.     

MRI of meniscal bucket-handle tears

Objective. A meniscal bucket-handle tear is a tear with an attached fragment displaced from the meniscus of the knee joint. Low sensitivity of MRI for detection of bucket-handle tears (64% as compared with arthroscopy) has been reported previously. We report increased sensitivity for detecting bucket-handle tears with the use of coronal short tau inversion recovery (STIR) images. Design and patients. Three hundred and twenty-seven patients who had MRI of the knee between October 1994 and December 1996 and subsequently underwent arthroscopy were included in the study. We prospectively and retrospectively reviewed the MR examinations of the 30 patients with arthroscopically proven bucket-handle tears. Each of two observers examined each scan for the three traditional findings of bucket-handle tears: a double posterior cruciate ligament sign, a flipped meniscus sign and/or a fragment in the intercondylar notch. We also assessed STIR images in the coronal plane through the menisci looking for an area of increased signal within either meniscus with a displaced meniscal fragment. Results. By using four criteria for diagnosis of meniscal bucket-handle tears, our overall sensitivity compared with arthroscopy was 93% (28 of 30 meniscal bucket-handle tears seen at arthroscopy were detected by MRI). The meniscal fragment was well visualized in all 28 cases on coronal STIR images. The double posterior cruciate ligament sign was seen in 8 of 30 cases, the flipped meniscus was seen in 10 of 30 cases and a fragment in the intercondylar notch was seen in 18 of 30 cases. Conclusion. By using four criteria for diagnosis of bucket-handle tears, overall diagnostic sensitivity of MRI compared with arthroscopy increased from the previously reported 64% to 93%. Coronal STIR images are useful for detecting small meniscal bucket-handle tears.     

MR imaging of meniscal bucket-handle tears: a review of signs and their relation to arthroscopic classification

Our objective was to review the MR imaging signs of meniscal bucket-handle tears and assess the relevance of these signs to the arthroscopic classification of displaced meniscal tears. Forty-five menisci in 42 patients who had a diagnosis of bucket-handle tear either on MR imaging or on subsequent arthroscopy (in which Dandy's classification of meniscal tears was used) were retrospectively analyzed for MR imaging findings of double posterior cruciate ligament (PCL), fragment within the intercondylar notch, absent bow tie, flipped meniscus, double-anterior horn, and disproportional posterior horn signs. Arthroscopy, which was considered as the gold standard, revealed 41 bucket-handle tears (either diagnosed or not diagnosed by MR imaging) in 38 patients (33 males, 5 females). There was a stastistically significant male preponderance for the occurrence of meniscal bucket-handle tears. Overall, sensitivity and positive predictive value of MR imaging for the detection of meniscal bucket-handle tears were calculated as 90%. Common MR imaging signs of meniscal bucket-handle tears in arthroscopically proven cases of such tears were the fragment in the notch and absent bow tie signs (98% frequency for each). Double-PCL, flipped meniscus, double-anterior horn, and disproportional posterior horn signs, however, were less common (32, 29, 29, and 27%, respectively). An arthroscopically proven bucket-handle tear was found in all patients who displayed at least three of the six MR imaging signs of meniscal bucket-handle tears. The presence of three or more MR imaging signs of meniscal bucket-handle tears is highly suggestive of this condition. Electronic Publication     

Healing results of meniscal tears left in situ during anterior cruciate ligament reconstruction: a review of clinical studies

The presence of peripheral meniscal tears is common at the time of anterior cruciate ligament (ACL) reconstruction. Techniques to preserve the maximum amount of meniscal tissue include “non operative” management (tear left alone, without repair or removal), meniscus repair, partial meniscectomy. There is a lack of consensus guidelines about the management of peripheral stable meniscal tears. When to remove, let alone or repair? We performed an evidence-based review of the outcomes of stable meniscal tears left in situ during ACL surgery, in order to assess the effectiveness of this popular procedure. Clinical and anatomical results (arthrography or second look arthroscopy) were analyzed. Our literature search yielded ten relevant studies (9 level IV, 1 level III). The mean time of follow-up was 16 months. Pain or mechanical symptoms related to the medial tibiofemoral joint were reported in 0–66% of cases. Subsequent medial meniscectomy or repair were performed in 0–33% of cases. Pain or mechanical symptoms related to the lateral tibiofemoral joint were reported in 0–18% cases. Subsequent lateral meniscectomy or repair were performed in 0–22% cases. A complete healing occurred in 50–61% cases for the medial meniscus and in 55–74% cases for the lateral meniscus. No definite conclusion can be made with regard to these results. The conservative approach is more effective for lateral menisci. The rate of bad results for the medial meniscus remains high when a conservative treatment is used. For the medial meniscus, repair of stable peripheral tears may be always indicated to decrease the risk of postoperative pain or subsequent meniscectomy.     

Meniscal tears on knee arthrography: Patterns of arthrographic abnormalities

The presence or absence of a meniscal tear was established in 340 out of 475 consecutive patients who had double contrast knee arthrograms. The accuracy in these 340 cases was 95% for both the medial and lateral menisci although the specificity for lateral tears was only 0.64. Analysis of the pattern of arthrographic abnormalities revealed that both medial and lateral tears usually involved the posterior horn of the meniscus. Posterior horn abnormalities rarely caused a false positive diagnosis of a meniscal tear. In contrast, isolated blunting of the anterior horn of either the lateral or medial meniscus was an unreliable sign of a tear and accounted for many of the false positive diagnoses. It is concluded that careful attention to the posterior horn of each meniscus is essential for accurate arthrographic diagnosis of a meniscal tear.     

Analysis of meniscal and chondral lesions accompanying anterior cruciate ligament tears: relationship with age,time from injury,and level of sport

The purposes of this multi-center study were: (a) to document the location and type of meniscal and chondral lesions that accompany anterior cruciate ligament (ACL) tears, and (b) to test for possible relationships between these lesions and patient age, time from initial injury (TFI), and sports level (i.e., recreation, amateur, professional, and national). The cases of 764 patients with ACL tears who underwent arthroscopy for the first time were retrospectively analyzed. The group included 684 males and 80 females of mean age 27 years (range 14–59 years). The mean TFI was 19.8 months (range 0.2–360 months). Eighty-seven percent of the group engaged in regular sporting activity. Thirty-seven percent had medial meniscal tears, 16% had lateral meniscal tears, and 20% had tears of both menisci. The most common tear types were longitudinal tears in the posterior and middle horns of both menisci. Tears of the lateral meniscus were more centrally located than those of the medial meniscus. Incomplete tears and radial tears were significantly more common in the lateral meniscus. Nineteen percent of the knees had one or more chondral lesions. Sixty percent of the chondral lesions were located in the medial tibio-femoral compartment. Patient age was statistically associated with presence of a medial meniscal tear, presence of a grade 3 or 4 chondral lesion, and presence of a complex tear of the medial meniscus. Sports level was not statistically related to any of the parameters studied. The odds of having a medial meniscal tear at 2 to 5 years TFI were 2.2 times higher than the odds in the first year post-injury, and the odds at >5 years were 5.9 times higher than at 0 to 12 months TFI. The frequency of lateral meniscal tear remained fairly constant at 2 years TFI. The odds of having a grade 3 or 4 chondral lesion were 2.7 times greater at 2 to 5 years TFI than they were at 1 year post-injury, and these odds increased to 4.7 when patients at >5 years TFI were compared to those in the 2 to 5 years category. Multivariate analysis demonstrated that TFI and age were equally important predictors of lateral meniscal tears and of grade 3 or 4 chondral lesions; however, TFI was the better predictor of medial meniscal tear.This multi-center study was performed by the Turkish Society of Sports Traumatology, Arthroscopy and Knee Surgery. It was presented as a poster at the ESSKA 2000 Congress in London, UK     

MR imaging of anterior cruciate ligament tears: is there a gender gap?

Objective Clinically, females receive anterior cruciate ligament (ACL) tears more commonly than males. We explored whether gender differences exist in MR imaging patterns of ACL tears.Design and patients At 1.5T, two observers evaluated MR examinations of 84 consecutive age-matched patients (42 males, 42 females, aged 16–39) with ACL tears, for mechanism of injury, extent and type of tear, the presence of secondary signs and associated osseous, meniscal and ligamentous injuries.Results The most common mechanism of injury for both females and males was the pivot shift mechanism (67 and 60%, respectively). Females were more commonly imaged in the acute stage of tear than males (98 and 67%, respectively, p=0.001) and more commonly possessed the typical posterolateral tibial bone contusion pattern (88 and 62%, respectively, p=0.0131). Males exhibited a deeper femoral notch sign (2.7 and 2.0 mm, p=0.007) and medial meniscal, lateral collateral ligament and posterior cruciate ligament injuries more commonly than females (48 and 24%, p=0.009, 30 and 7%, p=0.035, 17 and 0%, p=0.035). There was no significant difference between genders for the presence of other secondary signs and contusion patterns, associated lateral meniscal tears, presence of O'Donoghue's triad or associated medial collateral ligament injuries.Conclusion Gender differences in MR imaging patterns of ACL tears exist: females are more commonly imaged in the acute stage and more commonly possess posterolateral tibial bone contusions; males have a more severe presentation than females, associated with more severe lateral femoral condyle and soft tissue injuries.     

0.2-Tesla magnetic resonance imaging of internal lesions of the knee joint: a prospective arthroscopically controlled clinical study

The results of magnetic resonance imaging (MRI) were compared with those of arthroscopy in a prospective series of 244 patients. A dedicated system for MRI of limbs and peripheral joints – the 0,2-T Artoscan (Esaote, Italy) – was used for imaging knee joint lesions. T1-weighted spin-echo sagittal images, T2-weighted gradient-echo coronal images, and axial views for lesions of the femoropatellar joint were acquired. Paraxial sagittal and oblique coronal views were obtained for imaging of the cruciate ligaments. This protocol allowed excellent visualization of the cruciate ligaments and medial and lateral meniscus in almost all patients. Compared with arthroscopy performed within 48 h after imaging, the sensitivity, specificity, and accuracy were respectively 93%, 97%, and 95% for tears of the medial meniscus; 82%, 96%, and 93% for tears of the lateral meniscus; 100%, 100%, and 100% for tears of the posterior cruciate ligament; 98%, 98%, and 97% for tears of the anterior cruciate ligament; and 72%, 100%, and 92% for full-thickness articular cartilage lesions. The examination can be performed within 30–45 min at lower cost than diagnostic arthroscopy. MRI with a 0.2-T magnet is a safe and valuable adjunct to the clinical examination of the knee and an aid to efficient preoperative planning. Received: 13 October 1997 Accepted: 3 March 1998     

Value of the coronal plane in MRI of internal derangement of the knee

Sagittal images usually receive the most scrutiny in the magnetic resonance evaluation of meniscal and anterior cruciate ligament tears. We assessed the relative contribution of the coronal view. All knee magnetic resonance examinations performed over a 2-year period that had surgical confirmation were reviewed with respect to the presence of meniscal and anterior cruciate ligament tears. The appearance of an attenuated but uninterrupted anterior cruciate ligament was also evaluated. The coronal and sagittal plane images were evaluated separately. The study included 68 medial menisci, 67 lateral menisci, and 71 anterior cruciate ligaments. The coronal view is especially useful in the evaluation of the lateral meniscus. An anterior cruciate ligament that appears attennated but uninterrupted should be considered intact. The anterior cruciate ligament may be evaluated on the coronal view. The coronal view should be regarded as similar to the lateral chest radiograph, which supplements, but does not replace, the frontal chest radiograph.Presented at the Annual Meeting of the Radiological Society of North America, December 2, 1992, Chicago, Illinois