Background:

Femoral tunnels that are not anatomically placed within the native anterior cruciate ligament (ACL) footprint during ACL reconstruction are associated with residual instability, graft rupture, and poor clinical outcomes. Although surgeons may intend to place their femoral tunnels within the native ACL attachment, this is not always achieved. This study assesses the variation between intended and achieved femoral tunnel positions in a large cohort of experienced ACL surgeons.

Hypothesis:

The accuracy with which experienced ACL surgeons achieve their intended femoral tunnel position is dependent on viewing portal, localization strategy, and drilling technique.

Study Design:

Controlled laboratory study.

Methods:

A total of 221 surgeons indicated their intended femoral tunnel location on a true lateral radiograph of a cadaveric knee specimen and a scaled photograph. Each surgeon then arthroscopically demonstrated the femoral tunnel on the specimen. The position was captured using fluoroscopy. The Euclidean distance (the straight-line distance between 2 points) between the intended and achieved tunnel positions, referenced to a grid applied to the lateral femoral condyle, was compared. Data were analyzed according to surgeons’ viewing portal (anteromedial [AM] or anterolateral [AL]), tunnel localization strategy (offset aimer, estimation from landmarks, ACL ruler, or C-arm fluoroscopy), and stated drilling technique (transtibial, AM portal, or outside-in).

Results:

Surgeons who viewed the lateral intercondylar notch wall through the AM portal were closer (mean distance, 9.5) to their intended position than those who viewed through the AL portal (mean distance, 15.1; P < .0001). By localization strategy, the mean distance between achieved and intended tunnel positions was greater for surgeons who used an offset aimer (14.5) and estimated the femoral tunnel position (12.9) than for those using a malleable ACL ruler (8.1; P < .0001) and fluoroscopy (4.3; P < .0001). Surgeons’ preferred drilling technique (AM portal, transtibial, or outside-in) had no effect on distance between intended and achieved positions. However, the mean achieved position was higher in the intercondylar notch for those using transtibial drilling (P < .042).

Conclusion:

Surgeons using the AM portal to view the femoral attachment site were closer to their intended tunnel position than those who viewed it with the arthroscope in the AL portal. Surgeons who used fluoroscopy to localize femoral tunnel position were the closest to their intended position. Those who used estimation or an offset aimer had the farthest distance between achieved and intended tunnel positions.

Clinical Relevance:

Although accurate tunnel placement can be achieved using any method, given the disparity between intended and achieved tunnel positions, it may be advisable, even for high-volume surgeons, to verify the placement of their tunnels using either fluoroscopy or a malleable ACL ruler to ensure that they achieve their intended position. Fluoroscopy may be particularly useful for cases where the native femoral stump is no longer visible and for revisions. Viewing through the AM portal is recommended to aid accuracy of tunnel placement.

中文翻译：

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前交叉韧带股骨隧道放置：221位国际大容量ACL外科医生的预期对位与已获位置的分析。

背景：

在ACL重建过程中未在解剖学上放置在天然前交叉韧带（ACL）足迹内的股骨隧道与残留的不稳定性，移植物破裂和不良的临床预后相关。尽管外科医生可能打算将股骨隧道放置在原始ACL附件内，但这并不总是可以实现的。这项研究评估了一大批有经验的ACL外科医生的预期和完成的股骨隧道位置之间的差异。

假设：

经验丰富的ACL外科医生达到其预期的股骨隧道位置的准确性取决于观察门，定位策略和钻孔技术。

学习规划：

对照实验室研究。

方法：

共有221位外科医生在尸体膝盖标本的真实侧面X光照片和比例照片上表明了他们预期的股骨隧道位置。然后，每位外科医生用关节镜在标本上显示股骨隧道。使用荧光检查法捕获位置。比较了预期的和已实现的隧道位置之间的欧几里得距离（两点之间的直线距离），该距离参考应用于股外侧lateral的网格。根据外科医生的观察门户（前内侧[AM]或前外侧[AL]），隧道定位策略（偏移瞄准器，地标估计，ACL标尺或C型臂透视）和陈述的钻探技术（胫骨，AM）分析数据门户或从外而内）。

结果：

与通过AL门户观察的外科医生（平均距离为15.1；P <.0001）相比，通过AM门观察的外侧con间切口壁的外科医生更接近其预期位置（平均距离为9.5 ）。通过定位策略，使用偏移瞄准器（14.5）并估计股骨隧道位置（12.9）的外科医生比使用可延展ACL尺的外科医生（8.1; P <.0001）达到和预期的隧道位置之间的平均距离更大。透视检查（4.3；P <.0001）。外科医生的首选钻孔技术（AM门，胫骨或由外而内）不会影响预期位置和实现位置之间的距离。但是，对于使用胫骨钻孔的患者，achieved间切口的平均达到位置更高（P <.042）。

结论：

与使用AL门户中的关节镜观察股骨附着部位的外科医生相比，使用AM门户来观察股骨附着部位的外科医生更接近其预期的隧道位置。使用荧光透视法定位股骨隧道位置的外科医生最接近其预期位置。那些使用估算或偏移瞄准器的人在已达到的隧道位置和预期的隧道位置之间的距离最远。

临床相关性：

尽管可以使用任何方法来实现准确的隧道布置，但考虑到预期的和已实现的隧道位置之间的差异，建议使用透视检查或可延展的ACL标尺，即使对于大批量的外科医生，也要验证其隧道的布置，以确保他们达到了预期的位置。透视检查对于股骨残端不再可见和翻修可能特别有用。建议通过AM门户进行查看以提高隧道布置的准确性。