Kendal Joseph K, Clark Damian, Longino David, Marion Travis E, Buckley Richard, Schneider Prism S, Martin Ryan
Department of Surgery, Section of Orthopaedic Surgery, University of Calgary, Health Sciences Center, Northwest Calgary, Alberta, Canada.
Department of Orthopaedics, Southmead Hospital, Bristol, United Kingdom.
J Knee Surg. 2020 Feb;33(2):132-137. doi: 10.1055/s-0038-1676799. Epub 2019 Jan 24.
Posterolateral tibial plateau (PLTP) fractures are often associated with anterior cruciate ligament (ACL) incompetence, such as tibial eminence fractures. Both occur from a pivot shift like mechanism. Malreductions of the tibial plateau most frequently occur in the posterolateral quadrant. Acquiring adequate intraoperative visualization of the PLTP poses a challenge. We hypothesized that visualization of PLTP could be improved by positioning the knee at 110 degrees of flexion with the addition of a varus anterolateral rotatory vector. This position and maneuver take advantage of both the nonisometric nature of the lateral soft tissues and, when present, ACL incompetence. In this cadaveric study, we digitally quantified the percentage of the lateral tibial plateau visualized under different conditions after performing an anterolateral surgical approach with submeniscal arthrotomy. Four conditions were assessed for articular visualization: (1) 30 degrees of knee flexion, (2) 110 degrees of knee flexion, (3) 110-degrees of knee flexion plus varus anterolateral rotatory vector, (4) 110-degrees of knee flexion plus varus anterolateral rotatory vector with ACL sacrifice (ACL incompetence model). In the ACL competent models, maximal lateral tibial plateau exposure was obtained with the knee positioned at 110 degrees of flexion with a varus anterolateral rotatory vector (58.2%, range: 52.9-63.4%). Articular visualization was further improved with the ACL incompetent model (82.4%, range: 77.1-87.7%), modeling a tibial eminence fracture.
胫骨平台后外侧（PLTP）骨折常与前交叉韧带（ACL）功能不全相关，如胫骨髁间隆起骨折。两者均由类似轴移的机制引起。胫骨平台复位不良最常发生在后外侧象限。术中获得足够的PLTP可视化具有挑战性。我们假设，通过将膝关节置于110度屈曲位并增加内翻前外侧旋转向量，可以改善PLTP的可视化。这种位置和操作利用了外侧软组织的非等长特性，以及存在ACL功能不全的情况。在这项尸体研究中，我们在前外侧半月板下关节切开手术入路后，对不同条件下外侧胫骨平台可视化的百分比进行了数字量化。评估了四种关节可视化条件：（1）膝关节屈曲30度，（2）膝关节屈曲110度，（3）膝关节屈曲110度加内翻前外侧旋转向量，（4）膝关节屈曲110度加内翻前外侧旋转向量并牺牲ACL（ACL功能不全模型）。在ACL功能正常的模型中，膝关节置于110度屈曲位并伴有内翻前外侧旋转向量时，可获得最大的外侧胫骨平台暴露（58.2%，范围：52.9 - 63.4%）。在ACL功能不全模型（模拟胫骨髁间隆起骨折）中，关节可视化进一步改善（82.4%，范围：77.1 - 87.7%）。
