Dienst Michael, Schneider Guenther, Altmeyer Katrin, Voelkering Kristina, Georg Thomas, Kramann Bernhard, Kohn Dieter
Department for Orthopedic Surgery, University Hospital, Kirrberger Str. Geb. 37, Homburg/Saar, Germany.
Arch Orthop Trauma Surg. 2007 May;127(4):253-60. doi: 10.1007/s00402-006-0177-7. Epub 2006 Jun 21.
To correlate cross sections of the intercondylar notch to cross sections of the anterior cruciate ligament (ACL) and to analyze gender-related differences in notch and ACL morphometry with an attempt to explain the observation that a small intercondylar notch and the female gender predispose to a rupture of the ACL.
High resolution MR imaging was performed on a 1.5 T magnet using a dedicated extremity-coil in ten left and ten right knee joints of 20 volunteers (10 male, 10 female, mean age 25 years) with no history of knee abnormalities. Continuous axial T2-weighted MR images perpendicular to the longitudinal axis of the ACL were acquired. Cross-sectional areas of the ACL midsubstance at the contact area to the posterior cruciate ligament were measured. For imaging and evaluation of the osseous limits of the intercondylar notch a 3D-dataset of the knee was acquired. Anterior, middle and posterior planes of the intercondylar notch were calculated and analyzed for measurement of the notch area AN and notch width index NWI. The ratio of the ACL cross-sectional area of the ACL and the cross-sectional area of the notch was defined as the ACL notch index (ANI) and used as a standardized tool for evaluation. For statistical evaluation, linear regression analysis was performed. Mean values between male and female were compared using a t test. In addition, five matched pairs of male and female volunteers of same height were analyzed.
Mean cross-sectional size of the ACL at the crossing with the PCL was 54.4 +/- 20.4 mm2. Regression analysis showed a significant correlation (P < 0.05) of the ACL cross-sectional area to the notch areas on all three planes and NWI, respectively. Comparison between the sexes revealed that female participants had significantly smaller cross-sectional areas of the ACL, the notch areas, the NWI and ANI. This difference was found for both the complete study group and the matched pairs of same height.
The smaller the intercondylar notch the smaller the cross-sectional area of the ACL midsubstance. In addition to the impingement of the ACL at the anterior and posterior roof of the notch, a biomechanically weaker ACL may be the reason for disposition to an ACL rupture in patients with a small intercondylar notch. Women have a thinner ACL midsubstance than men of the same height which may be one of the critical etiologic factors that predispose women to an ACL rupture.
将髁间切迹的横截面与前交叉韧带（ACL）的横截面进行关联，并分析髁间切迹和ACL形态测量的性别差异，以试图解释髁间切迹小和女性性别易导致ACL断裂这一观察结果。
对20名志愿者（10名男性，10名女性，平均年龄25岁）的10个左膝关节和10个右膝关节，使用专用的肢体线圈在1.5T磁体上进行高分辨率磁共振成像，这些志愿者无膝关节异常病史。获取垂直于ACL纵轴的连续轴向T2加权磁共振图像。测量ACL中点在与后交叉韧带接触区域的横截面积。为了对髁间切迹的骨边界进行成像和评估，获取膝关节的三维数据集。计算并分析髁间切迹的前、中、后平面，以测量切迹面积AN和切迹宽度指数NWI。将ACL的横截面积与切迹的横截面积之比定义为ACL切迹指数（ANI），并用作标准化评估工具。进行线性回归分析以进行统计学评估。使用t检验比较男性和女性的平均值。此外，对五对身高相同的男性和女性志愿者进行了分析。
ACL与PCL交叉处横截面积的平均值为54.4±20.4mm²。回归分析表明，ACL横截面积与所有三个平面上的切迹面积以及NWI分别具有显著相关性（P<0.05）。性别比较显示，女性参与者的ACL横截面积、切迹面积、NWI和ANI明显较小。在整个研究组以及身高相同的配对组中均发现了这种差异。
髁间切迹越小，ACL中点的横截面积越小。除了ACL在切迹的前、后顶部受到撞击外，生物力学上较弱的ACL可能是髁间切迹小患者易发生ACL断裂的原因。与身高相同的男性相比，女性的ACL中点更薄，这可能是女性易发生ACL断裂的关键病因之一。
