正常前交叉韧带前内侧束和后外侧束的MRI表现

目的:探讨MRI显示前交叉韧带(ACL)前内侧束(AMB)和后外侧束(PLB)的方法及其正常表现。材料和方法:对20例正常志愿者及40例经手术或膝关节镜证实无ACL损伤者行T2*WI对比的三维梯度回波多回波成像(3D-MEDIC)检查,通过多平面重建(MPR)显示ACL的AMB和PLB的形态。结果:(1)横轴面:ACL自股骨端向胫骨端走行过程中形态逐渐变化:近股骨附着层面呈带状;中部层面呈不对称的倒"V"形,PLB大于AMB;胫骨附着层面呈倒"U"字形。(2)平行ACL的斜冠状面:AMB和PLB呈"人"字形分布。(3)在斜冠状位平行ACL的斜矢状面:51例(85%)可区分出前内侧束(AMB)和后外侧束(PLB)。结论:利用高分辨三维MR成像多平面重建技术能够帮助显示ACL的主要AMB和PLB分支。     

前交叉韧带前内侧束或后外侧束损伤的MRI3D-MEDIC表现

目的 探讨前交叉韧带(anterior cruciate ligament,ACL)前内侧束(anteromedial bundle,AMB)或后外侧束(posterolateral bundle,PLB)撕裂的MRI表现.方法 本组41例,经膝关节镜或手术证实为ACL部分撕裂,其中AMB撕裂22例,PLB撕裂19例,使用MRI多回波数据组合(multipleecho data image combination sequence,MEDIC)三维梯度回波序列扫描,经斜矢状,横轴和斜冠状面图像重建,观察AMB或PLB撕裂后的MRI表现.结果 19例PLB撕裂和22例AMB撕裂,在MRI斜冠状位层面上显示ACL正常的"人"字形结构被破坏及在横轴层面显示正常的倒"V"字形结构被破坏;10例PLB撕裂表现为外侧束或外侧臂消失呈单束或单臂征;10例AMB撕裂表现为内侧束或内侧臂消失亦呈单束或单臂征.结论 MRI 3DMEDIC 三维梯度回波序列扫描可显示AMB或PLB撕裂.     

膝关节前交叉韧带撕裂MRI多征象分析

前交叉韧带（anterior cruciate ligament,ACL）起自股骨外侧髁内侧面的后部,由外上向内下旋转走行,止于胫骨髁间棘略前外侧。ACL的作用主要防止胫骨向前移位和内旋,并限制膝关节过伸和股骨内旋,是维持膝关节稳定的主要结构之一。ACL撕裂是膝关节创伤常见的并发症,MRI能直接显示撕裂的ACL,并能显示关节其他结构的继发改变,是检查ACL撕裂准确和有效的非侵蚀性方法。     

磁共振膝关节斜冠状位扫描对前交叉韧带的评价

目的　探讨磁共振膝关节斜冠状位扫描对前交叉韧带的显示价值。方法　对 3 0例正常膝关节均行常规横断、斜矢状、冠状扫描 ,扫描序列还包括在斜矢状图像基础上行平行于前交叉韧带FSE序列斜冠状薄层无间隔T2 扫描 ,分析斜冠状、斜矢状及冠状位对正常前交叉韧带的显示情况。结果　正常膝关节于 1幅图片上可清楚显示ACL全程者 ,斜冠状显示率为 10 0 % (3 0 3 0 ) ,斜矢状位显示率为 83 .3 % (2 5 3 0 ) ,而冠状位前交叉韧带呈节段状 ,不能在 1幅图像中显示完整的ACL。结论　斜冠状位可在 1幅图像上完整显示前交叉韧带起止附着区及中间纤维束 ,有利于对前交叉韧带显示及损伤后的评价     

MRI多征象分析对前交叉韧带损伤的诊断价值

目的：评价MRI对前交叉韧带（anterior cruciate ligament,ACL）损伤多种征象的诊断价值。方法：回顾分析了128个膝关节的MR图像。全部膝关节均行关节镜检查,其中52个膝关节的ACL损伤,另外76个膝关节的ACL显示完整。在不告知关节镜结果的前提条件下,2名影像科医生共同对ACL损伤的5个直接征象和10个间接征象进行评价,意见不一致时协商解决差异。结果：在评价的5个直接征象中,ACL不连续和ACL走行异常具有相对高的诊断敏感性和特异性;在评价的10个间接征象中,大多数具有相对高的特异性和低的敏感性,其中空髁间窝征、Notch征、外侧半月板后角裸露征、PCL指数、冠状面PCL单层显示等征象特异性较高。结论：ACL损伤的直接征象为诊断的主要依据,以ACL不连续和ACL走行异常具有较高的诊断价值;ACL损伤的间接征象具有辅助诊断意义,其中空髁间窝征、Notch征、外侧半月板后角裸露征、PCL指数、冠状面PCL单层显示等征象最具有诊断价值。     

膝关节前交叉韧带前内侧束和后外侧束的MR成像研究

目的 提高对膝关节前交叉韧带前内侧束和后外侧束的影像认识,并探讨其3.0T MR的理想常规成像显示平面.方法 回顾性分析149例正常膝关节的3.0TMR图像,采用x2分割法分析前交叉韧带、前内侧束和后外侧束双束结构及双束上、中、下各段在MR矢状面、冠状面、横断面各成像平面显示率的差异.结果 前交叉韧带前内侧束和后外侧束双束结构显示率,横断面(115/149,77.2％)与冠状面(103/149,69.1％)比较,×2=2.4606,P＞0.0125;横断面、冠状面分别与矢状面(21/149,14.1％)比较,x2值分别为119.5138、92.8695,P值均＜0.0125.前内侧束和后外侧束双束上段显示率,横断面( 104/149,69.8％)与冠状面(7/149,4.7％)、矢状面(0/149,0)及冠状面与矢状面分别比较,x2值分别为135.0813、159.7526、7.1684,P值均＜0.0125.前内侧束和后外侧束双束中段显示率,横断面(108/149,72.5％)与冠状面(94/149,63.1％)比较,x2=3.0120,P＞0.0125;横断面、冠状面分别与矢状面( 10/149,6.7％)比较,x2值分别为134.7454、104.2173,P值均＜0.0125.前内侧束和后外侧束双束下段显示率,横断面(103/149,69.1％)与冠状面(110/149,73.8％)比较,x2=0.8065,P＞0.0125;横断面、冠状面分别与矢状面(18/149,12.1％)比较,x2值分别为100.5300、115.9132,P值均＜0.0125.前交叉韧带双束各段在MRI各序列上均呈低信号,形态、走行正常.结论 3.0TMR常规扫描平面能够在一定程度上显示前交叉韧带的双束结构,横断面和冠状面是较为理想的显像平面.     

膝关节后外侧结构的解剖与MRI研究

目的 改进膝关节后外侧结构MRI定位方法，提高后外侧结构损伤的诊断准确率。方法 解剖膝关节标本，辨认后外侧各结构起止点及走行，明确它们之间的解剖关系。以注水的输液器缝合标记各结构进行MRI扫描，测量各结构在矢状面和冠状面上与腓骨颈长轴之间的夹角。按照这些角度定位扫描正常膝关节，观察各结构在MRI中完整显示的情况。结果 （1）测得矢状面上腓侧副韧带和胴肌腱关节囊内部分与腓骨颈长轴的夹角分别为（11．5±1.7）°和（39．5±6，4）°冠状面上胴肌腱关节囊外部分和胴腓韧带与腓骨颈长轴夹角为（39.5±3．9）°和（31．9±3．9）°。（2）腓侧副韧带在11°后斜冠状位1个层面上完整显示占90％，胴肌腱关节囊内部分在40°后斜冠状位1个层面上完整显示占80％，胭肌腱关节囊外部分在内斜40°矢状位1个层面上完整显示占90％，胭腓韧带在外斜30°矢状位1个层面上完整显示占90％。此外，胴腓韧带在11°后斜冠状位1个层面上完整显示的占75％，股二头肌腱和髂胫束在常规冠状面均能够很好显示.结论 选择完整显示腓骨茎突和腓骨颈的冠状面和矢状面为基准面，按照后外侧各结构与腓骨颈长轴所呈角度进行定位，层厚2mm的MR扫描能很好地显示膝关节后外侧解剖结构。     

膝关节外侧副韧带MRI定位方法研究

目的改进膝关节磁共振成像（MRI）中膝关节外侧副韧带的定位方法,提高膝关节外侧副韧带（1ateral col-1atera lligament,LCL）的全程显示率和诊断膝关节外侧副韧带损伤的正确率。方法2010年11月～2012年7月我院212例患者共217个膝关节随机人组研究,记录在膝关节MRI外侧矢状面测量所得的腓骨长轴与膝关节间隙平面之间的夹角度数。在正中矢状面以该夹角度数来完成膝关节MRI斜冠状面定位。获得与腓骨长轴平行的膝关节斜冠状面MRIT2WI图像,观察外侧副韧带在斜冠状面上的显示情况。I级为韧带在单一层面全程显示,Ⅱ级为韧带在两个连续层面显示,Ⅲ级为韧带在两个以上层面显示。运用SPSS16．0统计软件进行卡方检验,分析膝关节外侧副韧带显示结果与性别、年龄、左右侧及定位角度之间的关系。结果用与腓骨长轴平行的膝关节斜冠状面MRIT2WI来显示膝关节外侧副韧带,LCLI级显示203个,LCLⅡ级显示13个,LCLnl级显示1个,定位角度71°～88°,平均78．30°±3．87°;膝关节外侧副韧带I级显示率与性别（P=285）、年龄（P=0．065）、左右侧（P=0．277）及定位角度（P=0．433）相关性均无统计学意义。结论与腓骨长轴平行的膝关节MRI斜冠状面是显示膝关节外侧副韧带的最佳层面,利用腓骨长轴与关节间隙平面的夹角定位,方法简单、结果准确。     

膝关节低场MRI最佳检查方法的回顾分析

目的:探讨膝关节低场磁共振的最佳检查方法。方法:在76例77个膝关节MRI检查中,冠状面图像的第一定位线是在横断面图像上内、外侧髁后缘连线的平行线;第二定位线是在矢状面图像上以胫骨髁间隆起的上缘为中心做股骨-胫骨长轴的平行线。矢状面图像的第一定位线是在冠状面图像上内、外侧半月板中心连线的垂线向外上内下倾斜,第二定位线是在横断面上内、外侧髁后缘连线的垂线向内前外后倾斜。结果:冠状面显示半月板、侧副韧带最佳,矢状面显示半月板、交叉韧带最佳,矢状面第一定位线平均倾斜角度(-x±s)为6.9°±1.3°,第二定位线倾斜角度平均为5.8°±1.4°。结论:在做膝关节MRI检查时,矢状面扫描双定位线的角度和方向要做适当调整,以便清晰显示前交叉韧带。     

319例不同病程前交叉韧带断裂患者胫骨髁间棘几何形态比较

目的:了解不同病程前交叉韧带(ACL)断裂患者胫骨髁间棘几何形态的差异,探讨其对ACL传统单束重建和解剖双束重建的临床意义。方法:2005年5月24日至2008年2月27日,用GE Healthcare Centricity RIS/PACKS系统对319例ACL断裂患者的胫骨平台内、外侧髁间棘的几何形态进行了测量,测量指标包括内侧髁间棘垂直高度、外侧髁间棘垂直高度、内外侧髁间棘顶点连线中点处的垂直高度、胫骨平台的内外宽度和内外侧髁间棘基底宽度之和。比较病程分别为≤3个月、>3个月且≤6个月、>6个月且≤12个月和>12个月的各组ACL断裂患者髁间棘形态测量值的差异。结果:与病程≤3个月的ACL断裂患者相比,病程>3个月且≤6个月的患者髁间棘几何形态改变不明显,病程>6个月且≤12个月的患者外侧髁间棘高度显著增加,病程>12个月的患者内、外侧髁间棘高度均显著增加。结论:ACL断裂患者随病程延长髁间棘几何形态有所改变。对病程长于12个月的患者,应考虑其胫骨内、外侧髁间棘增高对ACL重建术中胫骨骨道定位和ACL重建术后增生的髁间棘对移植物的撞击的影响。     

Grading of anterior cruciate ligament injury. Diagnostic efficacy of oblique coronal magnetic resonance imaging of the knee

OBJECTIVE: This study was undertaken to evaluate the diagnostic efficacy of additional oblique coronal magnetic resonance (MR) imaging of the knee for the grading of anterior cruciate ligament (ACL) injury. METHODS: We retrospectively reviewed MR images of the knee in 169 patients. The MR examinations included routine sequences and oblique coronal T2-weighted images, which oriented in parallel to the course of the femoral intercondylar roof. Two independent readers evaluated the status of the ACL by routine knee MR imaging and then by additional oblique coronal imaging. The severity of the ACL injury was graded using a 4-point system from MR images, namely, intact, low-grade partial tear, high-grade partial tear, and complete tear, and results were compared with arthroscopic findings. Weighted kappa statistics were used to analyze the diagnostic accuracy of routine knee MR imaging with and without additional oblique coronal imaging. RESULTS: The weighted kappa scores (kappaws) were 0.752 (reader 1) and 0.784 (reader 2) by routine knee MR imaging only; with additional oblique coronal imaging, the kappaws increased to 0.809 (reader 1) and 0.843 (reader 2). Interobserver agreements for routine knee MR imaging and additional coronal imaging were considered to be "very good" (kappaw = 0.851, 0.868, respectively). CONCLUSION: Additional use of oblique coronal MR imaging of the knee improves diagnostic accuracy in the grading of ACL injury.     

Relationship between mucoid hypertrophy of the anterior cruciate ligament (ACL) and morphologic change of the intercondylar notch: MRI and arthroscopy correlation

OBJECTIVE: The purpose of this study was to evaluate the relationship between mucoid hypertrophy of the anterior cruciate ligament (ACL) and morphologic change of the intercondylar notch. MATERIALS AND METHODS: We retrospectively reviewed the 105 patients with knee magnetic resonance imaging (MRI) with or without knee arthroscopy [group 1: patients with arthroscopic notchplasty (N = 47), group 2: knee arthroscopy demonstrating intact ACL (N = 33), and group 3: patients with normal knee MRI but no arthroscopy (N = 25)]. Groups 2 and 3 served as an arthroscopic and MR control group, respectively. Two musculoskeletal radiologists reviewed all MR examinations. The intercondylar notch width, notch index (width of intercondylar notch/width of femoral condyle), transverse notch angle (TNA), sagittal notch angle (SNA), and notch area were recorded on axial and sagittal MR images at the midpoint of Blumensaat's line which was identified on sagittal images. The diameter of the ACL was recorded on coronal MR images at the posterior end of Blumensaat's line. RESULTS: The mean values of the intercondylar notch width, notch index, TNA, SNA, notch area, and ACL diameter for the three groups were 16.0 mm/0.2/50.3 degrees /36.5 degrees /249.0 mm(2)/7.7 mm (group 1); 19.3 mm/0.3/52.9 degrees /40.2 degrees /323.4 mm(2)/4.8 mm (group 2); and 20.3 mm/0.3/51.4 degrees /39.1 degrees /350.8 mm(2)/4.5 mm (group 3). The intercondylar notch width, notch index, SNA, and notch area were smaller, and ACL diameter was thicker in group 1 compared with the other groups (p < 0.05). CONCLUSION: Patients with mucoid ACL hypertrophy show a narrower notch, a steeper notch angle, and a smaller notch area than control groups.     

MR imaging,MR arthrography,and specimen correlation of the posterolateral corner of the knee: an anatomic study

OBJECTIVE: We sought to evaluate the anatomy of the posterolateral aspect of the knee with anatomic dissection, MR imaging, MR arthrography, and sectional anatomy. MATERIALS AND METHODS: We assessed the posterolateral corner of the knee during dissection of one gross anatomic specimen. MR imaging and MR arthrography were performed in seven additional knee specimens. T1-weighted spin-echo MR images were obtained in the standard imaging planes as well as in the coronal oblique plane. The specimens underwent T1-weighted spin-echo MR imaging after administration of intraarticular contrast material and were sectioned into planes corresponding to those of the MR images. RESULTS: At anatomic dissection, the following posterolateral structures were identified: the arcuate ligament (medial and lateral limbs), fabellofibular ligament, popliteofibular ligament, popliteus tendon and its two posterior attachments to the lateral meniscus, fibular collateral ligament, direct and anterior arms of the tendon of the long head of the biceps femoris muscle, and direct and anterior arms of the tendon of the short head of the biceps femoris muscle. Correlation of MR imaging and anatomic findings showed that the popliteofibular ligament and oblique popliteal ligament were found in 57% and 100% of specimens, respectively. At least one of the two limbs of the arcuate ligament was identified in 71% of specimens. The fabellofibular ligament was not identified on MR images in any of the specimens. The anteroinferior and posterosuperior popliteomeniscal fascicles were identified in all specimens. CONCLUSION: The posterolateral corner of the knee comprises complex and variable anatomic structures. Recognition of these variations is important in the assessment of MR images of the knee.     

Acute anterior cruciate ligament stump entrapment in anterior cruciate ligament tears: MR imaging appearance

PURPOSE: To describe the magnetic resonance (MR) imaging appearance of anterior cruciate ligament (ACL) stump entrapment in patients who presented with decreased knee extension after rupturing the ACL. MATERIALS AND METHODS: MR images in 15 patients who had presented with a block to terminal knee extension after sustaining an ACL tear were retrospectively reviewed. The MR imaging appearances of entrapped ACL stumps were defined and correlated with arthroscopic and histologic findings. RESULTS: The entrapped ACL stumps had two distinct appearances. Type 1 stumps (n = 11) were characterized by a nodular mass located at the anterior aspect of the intercondylar notch, interposed between the lateral femoral condyle and tibia. Type 2 stumps (n = 4) were characterized by a tonguelike free end and angulation of the stump. Histologic evaluation of the resected specimens showed distorted ACL fibers intermixed with variable fibrosis and inflammation. CONCLUSION: Entrapment of an ACL stump can limit knee extension. The two observed appearances of entrapped ACL stumps likely represent two points along a spectrum of appearances, which possibly includes the cyclops lesion.     

Grading Anterior Cruciate Ligament Graft Injury after Ligament Reconstruction Surgery: Diagnostic Efficacy of Oblique Coronal MR Imaging of the Knee

Objective

The purpose of this study was to evaluate the diagnostic efficacy of using additional oblique coronal MRI of the knee for grading anterior cruciate ligament (ACL) graft injury after ligament reconstruction surgery.

Materials and Methods

We retrospectively reviewed 51 consecutive MR knee examinations of 48 patients who underwent both ACL reconstruction and follow-up arthroscopy. The MR examinations included the orthogonal axial, sagittal, coronal images and the oblique coronal T2-weighted images, which were oriented in parallel with the course of the femoral intercondylar roof. Two radiologists independently evaluated the status of the ACL grafts with using the routine knee MRI and then with adding the oblique coronal imaging. The severity of ACL graft injury was graded using a 3-point system from MR images as intact, partial tear or complete tear, and the results were compared with the arthroscopic results. Weighted kappa statistics were used to analyze the diagnostic accuracies of the knee MRI with and without the additional oblique coronal imaging. For each evaluation, the observers reported a confidence level for grading the ACL graft injuries in the two imaging groups.

Results

The weighted kappa values according to the routine knee MRI were 0.555 (reader 1) and 0.515 (reader 2). The inclusion of additional oblique coronal imaging increased the weighted kappa values to 0.666 (reader 1) and 0.611 (reader 2). The mean confidence levels by each reader were significantly higher (p < 0.01, paired t-test) with the additional oblique coronal imaging than by using the routine knee MRI alone.

Conclusion

The additional use of oblique coronal MRI of the knee improves both the diagnostic accuracy and confidence for grading ACL graft injury.     

Anterior cruciate ligament bundle measurement by MRI

Objective

An accurate in vivo method of measuring dimensions of the anteromedial (AM) and posterolateral (PL) anterior cruciate ligament (ACL) bundles has not been established. The purpose of this study was to measure each individual bundle using double oblique axial MR imaging of the ACL, to compare this with cadaveric measurements, and to investigate the range of measurements seen in normal subjects.

Materials and methods

In five cadaveric knees, measurements obtained of the proximal, middle, and distal segments of each ACL bundle from double oblique axial MR images were compared with direct measurements following anatomical dissection. Thereafter, the size of both bundles from 24 normal knees was measured using an identical MR technique. Inter-observer variation was calculated using intraclass correlation.

Results

ACL bundle measurement in the cadaveric knees had a strong correlation (r?=?0.93) with measurements obtained following anatomical dissection. No significant difference existed between measurements obtained from cadaveric knees and living normal subjects (p?>?0.05). Interobserver correlation for MR measurements was excellent (R?=?0.92–0.93). Overall, the long and short axis of the AM bundle were significantly larger than those of the PL bundle (p?<?0.05). Also, men showed significantly larger AM and PL bundles than women (p?<?0.05). Bundle size was not related to age or knee dominance.

Conclusion

The individual ACL bundles can be accurately measured on double oblique axial MR imaging. The AM bundle is larger in caliber than the PL bundle. Both bundles are larger in men than in women and there is no significant side-to side difference.     

Contribution of thin slice (1 mm) oblique coronal proton density-weighted MR images for assessment of anteromedial and posterolateral bundle damage in anterior cruciate ligament injuries

Purpose

To evaluate the diagnostic efficacy of using additional oblique coronal 1 mm proton density-weighted (PDW) MR imaging of the knee for detection and grading anterior cruciate ligament (ACL), anteromedial bundle (AMB) and posterolateral bundle (PLB) injuries.

Materials and methods

We prospectively assessed preoperative MR images of 50 patients (36 men, 14 women; age range, 18–62 years). First, we compared the diagnostic performance of routine sagittal (3 mm) and additional oblique coronal images (1 mm) for ACL tears. Then, we compared the tear types (AMB or PLB) and grade presumed from oblique coronal MR imaging with arthroscopy.

Results

Arthroscopy revealed ACL tear in 24 (48%) patients. There was significant difference between sagittal images and arthroscopy results for ACL tear recognition (p < 0.001). No significant difference was detected for oblique coronal images when compared with arthroscopy results (p = 0.180). Sensitivity and specificity values for ACL tear diagnosis were 37.04% and 95.65% for sagittal images; 74.07% and 91.30% for oblique coronal images. There was no significant difference between arthroscopy and oblique coronal MR images in grading AMB and PLB injuries (p > 0.05).

Conclusion

Addition of thin slice oblique coronal images to conventional sequences could better contribute to better verifying the presence of ACL tear and in determining its grade.     

Oblique MR imaging of the anterior cruciate ligament based on three-dimensional orientation

PURPOSE: To investigate the three-dimensional (3D) course of the anterior cruciate ligament (ACL) and determine the optimum planes for oblique full-length MRI of the ligament. MATERIALS AND METHODS: Twenty-five healthy volunteers were examined. Axial proton density-weighted (PDw) images of the knees of 20 volunteers were obtained. 3D paths along the course of the ACL and corresponding tangents were constructed. Angles between these tangents and reference lines RFL-1 (the line connecting the posterior edges of the femoral condyles), RFL-2 (the line through the intercondylar joint space), and RFL-3 (the line connecting the anterior and posterior edge of the medial tibial condyle) were measured. These angles were used for oblique T2-weighted (T2w) MRI of the knees of the remaining five volunteers, and the number of slices that depicted the entire ACL was calculated. RESULTS: The mean angles to the ACL were 74.0 degrees for RFL-1, 79.9 degrees for RFL-2, and 70.4 degrees for RFL-3. Full-length visualization of the ACL was demonstrated by 1.4 slices using the sagittal oblique plane prescribed for RFL-1, 2.4 slices using the sagittal oblique plane prescribed for RFL-2, and 1.4 slices using the coronal oblique plane prescribed for RFL-3. CONCLUSION: The ACL is best depicted using a sagittal oblique imaging plane angled at 80 degrees from a line through the intercondylar joint space.     

2D and 3D 3-tesla magnetic resonance imaging of the double bundle structure in anterior cruciate ligament anatomy

For anterior cruciate ligament (ACL) surgery using the anatomic approach of the double bundle concept it is helpful to describe the anteromedial (AM) and posterolateral (PL) bundle using Magnetic Resonance Imaging (MRI), since this is the most important preoperative parameter next to the physical examination. The aim of this study was to distinguish both bundles in MRI. In a prospective study we evaluated the double bundle structure in ACL anatomy with a 3-T ultra-high-field strength MR imaging of cadaver knees, which allows faster imaging times, increased resolution and increased signal-to-noise ratio. Using oblique sagittal and oblique coronal planes, we were able to distinguish the double bundle structure in each knee. The following arthroscopic evaluation of the knees confirmed our MRI findings. Our study demonstrates the possibility of distinguishing the two bundles in the native ACL with 3T MRI. Following examinations must study the value for clinical application by describing different rupture patterns of the bundles and correlating this to arthroscopy. It would be advantageous to know the rupture pattern in advance. Presurgical planning could be improved by reconstructing only the torn and preserving the intact bundle.