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.     

MR IMAGING OF DISPLACED MENISCAL TEARS OF THE KNEE: Importance of a "disproportional posterior horn sign"

Purpose: Meniscal tears associated with displaced fragments are clinically significant. We propose the "disproportional posterior horn sign" as a supportive criterion to identify a posterocentrally displaced meniscal fragment on MR imaging studies. If the meniscal posterior horn in the central portion appears larger than that in the peripheral section, it is considered positive for "disproportional posterior horn sign".Material and Methods: MR images obtained in 42 patients with 43 lesions, confirmed to have displaced meniscal tears, were included in this study. The MR images were retrospectively evaluated for the presence of the "disproportional posterior horn sign", as well as the other known signs.Results: The "disproportional posterior horn sign" was seen in 9 (20.9%) of 43 lesions, including 1 lateral discoid meniscal tear, 5 lateral meniscal tears and 3 medial meniscal tears. Five of them also had other signs of a displaced meniscal fragment. However, the remaining 4 cases only exhibited the "disproportional posterior horn sign". For the other MR signs, the "absent bow tie sign" was detected in 40 (93%) of 43 lesions, the "flipped meniscus sign" in 27 (62.8%) of 43 lesions, the "double posterior cruciate ligament sign" in 17 (39.5%) of 43 lesions and the "notch fragment sign" in 22 (51.2%) of 43 lesions.Conclusion: The "disproportional posterior horn sign" is helpful in demonstrating a posterocentrally displaced meniscal fragment, especially when other characteristic signs are unremarkable or absent.     

MRI对膝关节半月板桶柄样撕裂的诊断价值

目的　评价MRI诊断膝关节半月板桶柄样撕裂的应用价值。方法　经关节镜证实的 2 1例的桶柄样撕裂患者及 11例非桶柄样撕裂患者。采用百胜公司的关节专用磁共振成像系统进行扫描。观察以下 4种MRI征象 ,双前角征 ,双后交叉韧带征 ,髁间碎片征及领结消失征。结果　 3 2例患者中 ,出现双前角征的有 10例 ,双后交叉韧带征 5例 ,髁间碎片征 2 0例 ,领结消失征 2 5例。结论　MRI是诊断半月板桶柄样撕裂的有效手段 ,内侧半月板桶柄样撕裂的敏感性及特异性较外侧高 ,髁间碎片征是诊断内侧半月板桶柄样撕裂最有价值的征象     

Bucket-handle meniscal tears of the knee: sensitivity and specificity of MRI signs

OBJECTIVE: To determine the sensitivity and specificity of reported MRI signs in the evaluation of bucket-handle tears of the knee. DESIGN AND PATIENTS: A retrospective analysis of 71 knee MR examinations that were read as displaying evidence of a bucket-handle or "bucket-handle type" tear was performed. We evaluated for the presence or absence of the absent bow tie sign, the coronal truncation sign, the double posterior cruciate ligament (PCL) sign, the anterior flipped fragment sign, and a fragment displaced into the intercondylar notch. Sensitivity and specificity were calculated relative to the gold standard of arthroscopy. RESULTS: Forty-three of 71 cases were surgically proven as bucket-handle tears. The absent bow tie sign demonstrated a sensitivity of 88.4%. The presence of at least one of the displaced fragment signs had a sensitivity of 90.7%. A finding of both the absent bow tie sign and one of the displaced fragment signs demonstrated a specificity of 85.7%. The double PCL sign demonstrated a specificity of 100%. The anterior flipped meniscus sign had a specificity of 89.7%. CONCLUSIONS: Bucket-handle tears of the menisci, reported in about 10% of most large series, have been described by several signs with MRI. This report gives the sensitivity and specificity of MRI for bucket-handle tears using each of these signs independently and in combination. MRI is shown to be very accurate for diagnosing bucket-handle tears when two or more of these signs coexist.     

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.     

The flipped meniscus sign

Meniscal fragments may be difficult to detect on magnetic resonance (MR) imaging and yet are clinically significant. This paper describes and illustrates the MR appearance of an easily overlooked meniscal fragment. Ten knees, each appearing to show an abnormally large anterior meniscal horn (8 mm or more in height) were prospectively identified on MR images. In each case demonstrable large tears of the ipsilateral posterior horns were present (same meniscus as had large anterior horns). The lateral meniscus was involved in nine cases and the medial in one. Two of the ten patients imaged had surgically proven bucket-handle meniscal tears as well as meniscal fragments overlying the ipsilateral anterior horn. In one case previous MR imaging at our institution had demonstrated the affected anterior horn to be of normal caliber. The striking MR appearance of an abnormally enlarged anterior meniscal horn in association with a tear of the ipsilateral posterior horn suggests the presence of a meniscal fragment or of a posteriorly detached bucket-handle tear of the posterior horn of the meniscus.Presented at the Fifteenth Annual Skeletal Symposium of the Hospital of the University of Pennsylvania at Sun Valley, Idaho, USA, on 3 March 1992     

半月板下表面撕裂的MRI影像学表现

目的 探讨半月板下表面撕裂(meniscus lower surtace tear,MLST)的MRI影像学表现及与半月板撕裂传统分型的差异.方法 以"桶柄状撕裂""水平撕裂""复杂撕裂"为关键词,检索2018-06至2021-06在医院影像归档系统(picture archiving and communicatio...     

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.     

Hemi-bucket-handle tears of the meniscus: appearance on MRI and potential surgical implications

Objectives

To describe a type of meniscus flap tear resembling a bucket-handle tear, named a “hemi-bucket-handle” tear; to compare its imaging features with those of a typical bucket-handle tear; and to discuss the potential therapeutic implications of distinguishing these two types of tears.

Materials and methods

Five knee MR examinations were encountered with a type of meniscus tear consisting of a flap of tissue from the undersurface of the meniscus displaced toward the intercondylar notch. A retrospective analysis of 100 MR examinations prospectively interpreted as having bucket-handle type tears yielded 10 additional cases with this type of tear. Cases of hemi-bucket-handle tears were reviewed for tear location and orientation, appearance of the superior articular surface of the meniscus, presence and location of displaced meniscal tissue, and presence of several classic signs of bucket-handle tears.

Results

A total of 15/15 tears involved the medial meniscus, had tissue displaced toward the notch, and were mainly horizontal in orientation. The superior surface was intact in 11/15 (73.3%). In 1/15 (6.7%) there was an absent-bow-tie sign; 6/15 (40%) had a double-PCL sign; 14/15 (93.3%) had a double-anterior horn sign.

Conclusion

We describe a type of undersurface flap tear, named a hemi-bucket-handle tear, which resembles a bucket-handle tear. Surgeons at our institution feel this tear would likely not heal if repaired given its predominantly horizontal orientation, and additionally speculate the tear could be overlooked at arthroscopy. Thus, we feel it is important to distinguish this type of tear from the typical bucket-handle tear.     

MR imaging of displaced bucket-handle tear of the medial meniscus

A bucket-handle tear of the meniscus is a vertical or oblique tear with longitudinal extension toward the anterior horn in which the inner fragment is frequently displaced toward the intercondylar notch with resultant mechanical locking of the knee joint. A precise MR diagnosis requires identification of the centrally displaced fragment because the peripheral nondisplaced component may have only a subtle truncated or foreshortened appearance that may escape detection. Eighteen consecutive cases of displaced bucket-handle tears of the medial meniscus diagnosed by MR had a characteristic low-signal band extending across the joint and projecting over the medial tibial eminence. The posterior portion was parallel and beneath the posterior cruciate ligament on both sagittal and coronal images. Arthroscopy confirmed the presence and location of the displaced fragment in all 18 cases. Awareness of this characteristic MR finding may increase the sensitivity of MR imaging in the diagnosis of bucket-handle tears of the medial meniscus.     

The double ACL sign: an unusual bucket-handle tear of medial meniscus

Several characteristic magnetic resonance imaging (MRI) signs of meniscal bucket-handle tears are well known and widely used. This case report presents a new MRI sign of a meniscal bucket-handle tear. A 17-year-old boy visited our hospital because of the pain in his left knee. Preoperative MRI on sagittal view showed a tear in the anterior horn of the medial meniscus and a displaced fragment of the medial meniscus in front of the original anterior cruciate ligament (ACL), which looks like another ACL. Under arthroscopic examination, the bucket-handle medial meniscus displaced parallel to the ACL was observed. A longitudinal tear was extended from the anterior horn to the posterior horn of medial meniscus. To our knowledge, this new MRI sign of bucket-handle tear, “the double ACL sign”, has not been previously reported. Level of evidence V.     

MRI诊断膝关节半月板桶柄状撕裂

目的:总结分析半月板桶柄状撕裂的MRI征象和诊断价值.方法:回顾性分析146个经关节镜证实的膝关节MR图像,其中28个膝关节存在半月板桶柄状撕裂,记录如下5种MRI征象:碎块内移征、外周残半月板征、双PCL征、空领结征及双前角征,并分别计算每种征象诊断半月板桶柄状撕裂的敏感度、特异度、准确度、阳性预测值和阴性预测值.结...     

Abnormal superior popliteomeniscal fascicle and posterior pericapsular edema: indirect MR imaging signs of a lateral meniscal tear

OBJECTIVE. Because MR diagnosis of lateral meniscal tears can be difficult, indirect signs may be useful when a tear is suspected. We studied whether an abnormality of the superior popliteomeniscal fascicle or pericapsular edema was associated with lateral meniscal tears and thus may be an indirect MR imaging sign of a lateral meniscal tear. MATERIALS AND METHODS. We identified 59 consecutive patients who underwent both knee MR imaging examinations and knee arthroscopy. Thirty patients had lateral meniscal tears, and 29 had intact lateral menisci. We reviewed paired sagittal proton density- and T2-weighted MR images from these 59 patients for abnormal superior popliteomeniscal fascicles and edema surrounding the posterolateral capsule. RESULTS. The superior popliteomeniscal fascicles were abnormal in nine of the 30 patients with torn lateral menisci but were normal in all 29 patients with intact menisci (p = 0.001). Abnormal fascicles were apparent only when the lateral meniscal tear involved the posterior horn. Posterior pericapsular edema was seen in 10 patients with a torn posterior horn and in one patient with an anterior horn tear of the lateral meniscus, but in only two patients with intact menisci (p = 0.006). CONCLUSION. The presence of superior popliteomeniscal fascicle abnormalities and of posterior pericapsular edema is significantly associated with a tear of the lateral meniscus, most commonly in the posterior horn. Noting the presence of these findings may help improve the accuracy of MR diagnosis of lateral meniscal tears.     

Sagittal MR images of the knee: a low-signal band parallel to the posterior cruciate ligament caused by a displaced bucket-handle tear

A low-signal band parallel and anterior to the posterior cruciate ligament has been noted on sagittal MR images of the knee in some patients with other evidence for medial meniscal tears. It was hypothesized that this low-signal band represented the mesially displaced fragment of a bucket-handle tear. To verify this, we retrospectively reviewed MR and arthroscopic findings in 54 consecutive patients. Arthroscopy showed a bucket-handle tear of the medial meniscus in seven patients and was considered diagnostic. Sagittal MR images were reviewed without knowledge of the arthroscopic results. The presence of a curvilinear low-signal band above the tibial cortex anterior, inferior, and parallel to the posterior cruciate ligament was identified on MR images in all seven of the patients in whom the presence of a bucket-handle medial meniscal tear was confirmed by arthroscopy. Our findings suggest that a low-signal band anterior and parallel to the posterior cruciate ligament on sagittal MR images of the knee is caused by a mesially displaced bucket-handle tear of the medial meniscus.     

Reversed double PCL sign: unusual location of a meniscal fragment of the knee observed by MR imaging

A 36-year-old woman with tears of the anterior cruciate ligament and medial meniscus received a meniscectomy. The MR images obtained prior to the partial meniscectomy showed a bucket-handle meniscal tear with centrally displaced fragment lying anterior to the posterior cruciate ligament (PCL), representing a "double PCL sign"; however, after the meniscectomy, MR images demonstrated a fragment in the space posterior to the PCL where no structure is generally recognized except for the ligament of Wrisberg. This article reports a "reversed" double PCL sign, caused by inadequate surgical clearance of a bucket-handle tear of the medial meniscus.     

Reversed double PCL sign: unusual location of a meniscal fragment of the knee observed by MR imaging

A 36-year-old woman with tears of the anterior cruciate ligament and medial meniscus received a meniscectomy. The MR images obtained prior to the partial meniscectomy showed a bucket-handle meniscal tear with centrally displaced fragment lying anterior to the posterior cruciate ligament (PCL), representing a "double PCL sign"; however, after the meniscectomy, MR images demonstrated a fragment in the space posterior to the PCL where no structure is generally recognized except for the ligament of Wrisberg. This article reports a "reversed" double PCL sign, caused by inadequate surgical clearance of a bucket-handle tear of the medial meniscus.

     

Posterior double PCL sign: a case report of unusual MRI finding of bucket-handle tear of medial meniscus

Among the MRI signs of bucket-handle tears of medial meniscus, double posterior cruciate ligament (PCL) sign denotes a low signal band anterior and parallel to the PCL, which looks like another PCL in MR images. If the bucket-handle fragment subsequently tears at the anterior horn, the torn meniscal substance can be displaced to the posterosuperior region of the PCL, and looks like another PCL behind the original PCL. We propose the lesion be called the “posterior double PCL sign” in contrast to the ordinary double PCL sign. We present a case showing the posterior double PCL sign.     

MR imaging of meniscal malformations of the knee mimicking displaced bucket-handle tear

We report two cases of patients with lateral meniscal malformations of the knee that were found incidentally. Magnetic resonance imaging (MRI) of both cases showed a fragment-like meniscus structure located in the intercondylar notch, very similar to the "fragment in the intercondylar notch sign" observed in displaced bucket-handle tear. Arthroscopic examinations revealed a ring-shaped lateral meniscus in one case, and "flipped-over" lateral meniscus in the other. In the latter, a similar lateral meniscal malformation was observed contralaterally at MR arthrography.     

MR of the knee: the significance of high signal in the meniscus that does not clearly extend to the surface

On MR images of the knee it is sometimes impossible to determine with confidence if a focus of high signal in the meniscus is confined to the substance of the meniscus or if it extends to involve the surface. This is a critical differentiation because the latter represents meniscal tears that can be found and treated at arthroscopy, whereas the former represents degeneration, tears, or perhaps normal variants that cannot be detected or treated arthroscopically. We make an equivocal diagnosis of a tear when it is difficult to decide if signal in a meniscus involves the meniscal surface. We studied MR scans of the knee in 142 consecutive patients for the presence of such equivocal tears. Their prevalence was 14% (20/142); 17 were in the posterior horn of the lateral meniscus and three were in the posterior horn of the medial meniscus. In 13 cases with arthroscopy/arthrotomy correlation, no tears were found. In one of the 20 patients in whom the meniscus was removed during arthroplasty, histologic examination of the meniscus showed separation of collagen bundles, which was caused by meniscal degeneration confined to the substance of the meniscus. These results suggest that a meniscal tear is unlikely when MR scans show a focus of high signal in a meniscus that does not unequivocally extend to involve the surface of the meniscus.     

Meniscal gymnastics: common and uncommon locations of meniscal flip and flop

The majority of knee magnetic resonance imaging examinations are performed for meniscal evaluations. Displaced meniscal tears including free meniscal fragments are an important diagnosis as most of these tears are unstable and require surgical intervention. Magnetic resonance imaging can be an invaluable tool in the arthroscopic search for a free meniscal fragment. In addition to the commonly seen bucket-handle tears flipped into the intercondylar notch, it is important to be aware of less common locations where menisci may be displaced. First, we briefly summarize the basic meniscal anatomy and some of the more common tear patterns. We then investigate the broad range of meniscal migration.