Department of Orthopaedic Surgery, Cedars-Sinai Medical Center, Los Angeles, California, USA.
Orthopaedic Biomechanics Laboratory, Cedars-Sinai Medical Center, Los Angeles, California, USA.
Am J Sports Med. 2018 Jan;46(1):163-170. doi: 10.1177/0363546517732743. Epub 2017 Oct 19.
A hamstring autograft is commonly used in anterior cruciate ligament (ACL) reconstruction (ACLR); however, there is evidence to suggest that the tendons harvested may contribute to medial knee instability.
We tested the hypothesis that the gracilis (G) and semitendinosus (ST) tendons significantly contribute to sagittal, coronal, and/or rotational knee stability in the setting of ACLR with a concurrent partial medial collateral ligament (MCL) injury.
Controlled laboratory study.
Twelve human cadaveric knees were subject to static forces applied to the tibia including an anterior-directed force as well as varus, valgus, and internal and external rotation moments to quantify laxity at 0°, 30°, 60°, and 90° of flexion. The following ligament conditions were tested on each specimen: (1) ACL intact/MCL intact, (2) ACL deficient/MCL intact, (3) ACL deficient/partial MCL injury, and (4) ACLR/partial MCL injury. To quantify the effect of muscle loads, the quadriceps, semimembranosus, biceps femoris, sartorius (SR), ST, and G muscles were subjected to static loads. The loads on the G, ST, and SR could be added or removed during various test conditions. For each ligament condition, the responses to loading and unloading the G/ST and SR were determined. Three-dimensional positional data of the tibia relative to the femur were recorded to determine tibiofemoral rotations and translations.
ACLR restored anterior stability regardless of whether static muscle loads were applied. There was no significant increase in valgus motion after ACL transection. However, when a partial MCL tear was added to the ACL injury, there was a 30% increase in valgus rotation ( P < .05). ACLR restored valgus stability toward that of the intact state when the G/ST muscles were loaded. A load on the SR muscle without a load on the G/ST muscles restored 19% of valgus rotation; however, it was still significantly less stable than the intact state.
After ACLR in knees with a concurrent partial MCL injury, the absence of loading on the G/ST did not significantly alter anterior stability. Simulated G/ST harvest did lead to increased valgus motion. These results may have important clinical implications and warrant further investigation to better outline the role of the medial hamstrings, particularly among patients with a concomitant ACL and MCL injury.
A concurrent ACL and MCL injury is a commonly encountered clinical problem. Knowledge regarding the implications of hamstring autograft harvest techniques on joint kinematics may help guide management decisions.
腘绳肌腱自体移植物常用于前交叉韧带（ACL）重建（ACLR）；然而，有证据表明，所采集的肌腱可能导致内侧膝关节不稳定。
我们检验了这样一个假设，即在 ACLR 中同时伴有部分内侧副韧带（MCL）损伤的情况下，腘绳肌（G）和半腱肌（ST）肌腱对矢状面、冠状面和/或旋转膝关节稳定性有显著贡献。
对照实验室研究。
对 12 个人体尸体膝关节进行胫骨施加静态力，包括前向力以及内翻、外翻和内外旋转力矩，以在 0°、30°、60°和 90°的屈曲角度量化松弛度。对每个标本进行以下韧带条件测试：（1）ACL 完整/MCL 完整，（2）ACL 缺失/MCL 完整，（3）ACL 缺失/部分 MCL 损伤，以及（4）ACLR/部分 MCL 损伤。为了量化肌肉负荷的影响，对股四头肌、半膜肌、股二头肌、缝匠肌（SR）、ST 和 G 肌肉施加静态负荷。在各种测试条件下，可以添加或去除 G、ST 和 SR 的负载。对于每个韧带条件，确定加载和卸载 G/ST 和 SR 的响应。记录胫骨相对于股骨的三维位置数据，以确定胫骨股骨旋转和平移。
ACLR 恢复了前向稳定性，无论是否施加静态肌肉负荷。ACL 切断后，外翻运动没有明显增加。然而，当 ACL 损伤增加部分 MCL 撕裂时，外翻旋转增加了 30%（P<0.05）。当 G/ST 肌肉加载时，ACLR 恢复了接近完整状态的外翻稳定性。在没有 G/ST 肌肉负载的情况下加载 SR 肌肉可恢复 19%的外翻旋转；然而，它仍然明显不如完整状态稳定。
在伴有部分 MCL 损伤的膝关节中进行 ACLR 后，G/ST 无负载不会显著改变前向稳定性。模拟 G/ST 采集确实导致了外翻运动的增加。这些结果可能具有重要的临床意义，并需要进一步研究以更好地阐明内侧腘绳肌的作用，特别是在伴有 ACL 和 MCL 损伤的患者中。
同时发生 ACL 和 MCL 损伤是一种常见的临床问题。了解腘绳肌腱自体移植物采集技术对关节运动学的影响可能有助于指导管理决策。
