Background: Nowadays, the anterior cruciate ligament (ACL) injury has been one of the most common diseases of the knee joint. The relationships between the ACL injury and the anatomical structures are still controversial. This study aimed to identify the anatomical risk factors of ACL injury by magnetic resonance imaging (MRI) of the knee.
Methods: This was a retrospective study of 125 patients undergoing primary ACL reconstruction between July 2013 and May 2017. Another 125 patients without any organic knee joint injury were served as controls. The shape of intercondylar notch, the intercondylar notch width index, the intercondylar notch height index, the α angle, the β angle, and the medial and lateral tibial plateau slope were measured with MRI and compared. The data were compared by binary logistic regression to find the risk factors.
Results: The two groups differed in the proportion of male patients (70.4% vs. 52.0%, χ2 = 8.911, P = 0.003), but gender was excluded as a risk factor for ACL injury with regression analysis (odds ratio = 1.476, 95% confidence interval [CI]: 0.689-3.160, P = 0.317). The injured group was found to have a smaller notch width index (95% CI = 7.960E-23-2.154E-9, P < 0.001), a larger β angle (95% CI = 1.311-1.785, P < 0.001), and a larger lateral tibial plateau slope (95% CI = 1.201-1.683, P < 0.001). The cutoff values of notch width index, β angle, and the lateral tibial plateau slope were 0.252, 38.5°, and 7.5°, respectively.
Conclusions: In this study, a narrow intercondylar notch (intercondylar notch width index <0.252), a larger lateral tibial slope (>7.5°), and larger β angle (>38.5°) might be the factors associated with ACL injury.
Trial registration: ChiCTR-RRC-17014116; http://www.chictr.org.cn/showproj.aspx?proj=24119.
前交叉韧带断裂的解剖学危险因素 摘要 背景：随着时代的发展，前交叉韧带（anterior cruciate ligament， ACL）损伤已成为最为常见的膝关节损伤疾病之一。各个解剖学因素与ACL损伤之间的关系仍存在争议。本研究旨在通过磁共振研究评估各解剖学因素与ACL损伤之间的关系。 方法：此研究为一项回顾性研究，纳入2013年7月至2017年5月间行初次ACL重建的125位患者作为损伤组及另外125位无膝关节损伤病人作为对照组。通过磁共振图像测量和比较各解剖学指标包括髁间窝形态、髁间窝宽度系数、髁间窝高度系数、α角、β角及内外侧平台后倾角。研究方法采用回归分析确定各因素与ACL损伤之间的关系。 结果：两组男性患者比例存在明显差异（70.4% vs.52.0%, χ2=8.911, P =0.003），但回归分析显示性别并非导致 ACL损伤的危险因素(OR = 1.476, 95% CI:0.689-3.160, P=0.317)。损伤组患者相比于对照组有着较小的髁间窝宽度系数(95% CI =7.960E-23-2.154E-9，P＜0.001)、较大的β角(95% CI =1.311-1.785，P＜0.001)和较大外侧胫骨平台后倾角(95%CI=1.201-1.683, P＜0.001)，这三者各自的参考临界值为0.252, 38.5º和7.5º。 结论：本研究显示，较小的髁间窝宽度系数（＜0.252）、较大的外侧胫骨平台后倾角(＞7.5º) 以及较大的β角(＞38.5º)是导致ACL损伤的危险因素，同时β角可能成为评估ACL损伤最重要的危险因素。.
Keywords: Anatomy; Anterior Cruciate Ligament Injuries; Risk Factors.