Background:

Although the femoral tunnel position is crucial to anatomic single-bundle anterior cruciate ligament (ACL) reconstruction, the recommendations for the ideal femoral footprint position are mostly based on cadaveric studies with small sample sizes, elderly patients with unknown ACL status, and 2-dimensional techniques. Furthermore, a potential difference in the femoral ACL footprint position and ACL orientation between ACL-ruptured and ACL-intact knees has not been reported in the literature.

Hypothesis:

The femoral ACL footprint position and ACL orientation vary significantly between ACL-ruptured and matched control ACL-intact knees.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

Magnetic resonance images of the knees of 90 patients with an ACL rupture and 90 matched control participants who had a noncontact knee injury without an ACL rupture were used to create 3-dimensional models of the femur and tibia. The ACL footprints were outlined on each model, and their positions (normalized to the lateral condyle width) as well as ACL orientations were measured with an anatomic coordinate system.

Results:

The femoral ACL footprint in patients with an ACL rupture was located at 36.6% posterior and 11.2% distal to the flexion-extension axis (FEA). The ACL orientation was 46.9° in the sagittal plane, 70.3° in the coronal plane, and 20.8° in the transverse plane. The ACL-ruptured group demonstrated a femoral ACL footprint position that was 11.0% more posterior and 7.7% more proximal than that of the control group (all P < .01). The same patients also exhibited 5.7° lower sagittal elevation, 3.1° higher coronal plane elevation, and 7.9° lower transverse plane deviation (all P < .01). The optimal cutoff value of the femoral ACL footprint position to prevent an ACL rupture was at 30% posterior and 12% distal to the FEA.

Conclusion:

The ACL femoral footprint position might be a predisposing factor to an ACL rupture. Patients with a >30% posterior and <12% distal position of the femoral ACL footprint from the FEA might have a 51.2-times increased risk of an ACL rupture.

中文翻译：

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前交叉韧带的股骨位置可能是非接触性前交叉韧带破裂的诱因。

背景：

尽管股骨隧道的位置对于解剖性单束前交叉韧带（ACL）的重建至关重要，但理想的股骨足迹位置的建议主要基于尸体研究，样本量小，ACL状态未知的老年患者和二维技术。此外，在文献中还没有报道过ACL破裂和ACL完整的膝盖之间的股骨ACL足迹位置和ACL方向的潜在差异。

假设：

股骨ACL足迹位置和ACL方向在ACL破裂的膝盖和与之匹配的对照ACL完整的膝盖之间明显不同。

学习规划：

横断面研究；证据水平3。

方法：

使用90例ACL破裂患者的膝盖的磁共振图像和90例无ACL破裂的非接触性膝关节损伤的对照参与者的膝部磁共振图像来创建股骨和胫骨的3维模型。在每个模型上都概述了ACL足迹，并使用解剖坐标系测量了它们的位置（标准化为the外侧宽度）以及ACL方向。

结果：

ACL破裂患者的股骨ACL足迹位于屈伸轴（FEA）的后方36.6％和远侧11.2％。ACL方向在矢状平面中为46.9°，在冠状平面中为70.3°，在横向平面中为20.8°。ACL破裂组的股骨ACL足迹位置比对照组多11.0％，近端多7.7％（所有P <.01）。这些患者的矢状面抬高降低了5.7°，冠状面抬高了3.1°，横切面偏离降低了7.9°（所有P <.01）。防止ACL破裂的股ACL足印位置的最佳截止值位于FEA的后方30％和远端12％。

结论：

ACL股骨足迹位置可能是ACL破裂的诱因。从FEA中获得股骨ACL足迹的位置> 30％且远端位置<12％的患者，ACL破裂的风险可能会增加51.2倍。