Background:

The biomechanical function of the anterolateral structure (ALS), which includes the anterolateral joint capsule and anterolateral ligament (ALL), remains a topic of debate.

Hypothesis:

The ALS contributes to knee joint stability during the Lachman test and the pivot-shift test in anterior cruciate ligament (ACL)–deficient knees.

Study Design:

Controlled laboratory study.

Methods:

Fourteen fresh-frozen hemipelvis lower limbs were used. For 7 specimens, the anterior one-third of the ALS and the residual ALS were cut intra-articularly with a radiofrequency device. Subsequently, the ACL was cut arthroscopically. For the other 7 specimens, the ACL was cut first, followed by the anterior one-third of the ALS and the residual ALS intra-articularly. During the procedures, the iliotibial band (ITB) was kept intact. At each condition, the anterior tibial translation (ATT) during the manual Lachman test and the acceleration of posterior tibial translation (APT) and the posterior tibial translation (PTT) during the manual pivot-shift test were measured quantitatively with an electromagnetic measurement system. The mean values of those parameters were compared among 6 groups (ACL intact, one-third ALS cut, all ALS cut, ACL cut, ACL/one-third ALS cut, and ACL/all ALS cut).

Results:

The mean ATTs during the Lachman test and the mean APTs and PTTs in the ACL-cut conditions (ACL cut, ACL/one-third ALS cut, and ACL/all ALS cut) were significantly larger than those under the ACL-intact conditions (ACL intact, one-third ALS cut, all ALS cut) (P < .01). However, no statistically significant differences were observed among the intact, one-third ALS–cut, and all ALS–cut conditions, within the ACL-intact or ACL-cut conditions.

Conclusion:

Intra-articular dissection of the ALS did not increase the ATT during the Lachman test or the APT and PTT during the pivot-shift test under the intact condition of the ITB, regardless of the integrity of the ACL. When the ITB is intact, the ALS does not have a significant role in either anterior or dynamic rotatory knee stability, while the ACL does.

Clinical Relevance:

Recent growing interest about ALL reconstruction or ALS augmentation may not have a large role in controlling either anterior or dynamic rotatory knee instability in isolated ACL-deficient knees.

中文翻译：

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膝关节前外侧结构不影响前交叉韧带损伤中的前和动态旋转稳定性：使用电磁测量系统进行定量评估。

背景：

前外侧结构（ALS）的生物力学功能，包括前外侧关节囊和前外侧韧带（ALL），仍然是一个争论的话题。

假设：

ALS在Lachman测试和前交叉韧带（ACL）缺陷型膝盖的枢轴移动测试期间有助于膝盖关节的稳定性。

学习规划：

对照实验室研究。

方法：

使用了十四个新鲜冷冻的半盆骨下肢。对于7个标本，用射频装置关节内切开ALS的前三分之一和残余ALS。随后，用关节镜切除ACL。对于其他7个标本，首先切开ACL，然后再切开ALS的前三分之一和关节内残留的ALS。在手术过程中，胫束带（ITB）保持完整。在每种情况下，使用电磁测量系统定量测量手动Lachman测试期间的胫骨前平移（ATT）和手动枢轴移位测试期间的胫骨后平移（APT）和胫骨后平移（PTT）的加速度。比较了6组的这些参数的平均值（完整的ACL，三分之一的ALS切割，所有ALS切割，ACL切割，

结果：

Lachman测试期间的平均ATT和ACL切割条件（ACL切割，ACL /三分之一ALS切割以及ACL /所有ALS切割）下的平均APT和PTT均显着大于ACL切割条件下的平均ATT（完整的ACL，三分之一的ALS切割，所有的ALS切割）（P <.01）。但是，在完整的ACL切割条件或ACL切割条件下，完整，三分之一的ALS切割条件和所有ALS切割条件之间均未观察到统计学上的显着差异。

结论：

不论ACL的完整性如何，在ITB完整的情况下，ALS的关节内解剖都不会在Lachman测试期间增加ATT或在枢轴移位测试期间增加APT和PTT。当ITB完好无损时，ALS在前或动态旋转膝关节稳定性中没有重要作用，而在ACL中则没有。

临床相关性：

最近对ALL重建或ALS增强的兴趣日益增长，在控制孤立的ACL缺陷型膝关节的前膝关节或动态膝关节不稳定性方面可能没有太大作用。