Abstract：
BACKGROUND: In total hip arthroplasty via the direct anterior approach, appropriate exposure is critical to allow preparation of the femur. The objective of this study was to explore the optimal soft tissue releases needed to allow broaching of the femur through a combination of experimental tests and computer simulations.
METHODS: Fourteen full-body cadaveric specimens were included in this study. Total hip arthroplasty was performed via the direct anterior approach with the femur at 20° adduction and 20°extension. Soft tissue releases were performed sequentially, namely, the transverse iliofemoral ligament, descending iliofemoral ligament, ischio-femoral ligament, conjoint tendon, and obturator externus. After each release, the femur mobility was assessed by applying a 6 Nm external rotation torque and a 120 N distraction force. Subsequently, using specimen-specific models and models of the broach and handle, the broach passage after each release was simulated, and the release that allowed broach passage was analyzed.
RESULTS: The average external rotation after releasing the transverse and descending iliofemoral ligaments increased by 14.1° ± 6.1° and 13.8° ± 5.3°. With subsequent soft tissue releases, the rotational mobility increased incrementally, though the impact decreased. Impingement between the broach passage and the pelvis was mainly at the anterior superior iliac spine and the anterior inferior iliac spine. The volume of impingement decreased from 4.8 ± 4.5 cm3 after resection of the femoral head to 1.8 ± 1.6 cm3 and 1.2 ± 1.9 cm3 after release of the transverse and descending iliofemoral ligament, respectively.
CONCLUSIONS: With sequential soft-tissue releases, the femur mobility increased incrementally. However, the number of releases needed for each femur varied extensively between specimens. Most (10/14) femurs became accessible after the release of the ilio-femoral or ischio-femoral ligament.
METHODS: Fourteen full-body cadaveric specimens were included in this study. Total hip arthroplasty was performed via the direct anterior approach with the femur at 20° adduction and 20°extension. Soft tissue releases were performed sequentially, namely, the transverse iliofemoral ligament, descending iliofemoral ligament, ischio-femoral ligament, conjoint tendon, and obturator externus. After each release, the femur mobility was assessed by applying a 6 Nm external rotation torque and a 120 N distraction force. Subsequently, using specimen-specific models and models of the broach and handle, the broach passage after each release was simulated, and the release that allowed broach passage was analyzed.
RESULTS: The average external rotation after releasing the transverse and descending iliofemoral ligaments increased by 14.1° ± 6.1° and 13.8° ± 5.3°. With subsequent soft tissue releases, the rotational mobility increased incrementally, though the impact decreased. Impingement between the broach passage and the pelvis was mainly at the anterior superior iliac spine and the anterior inferior iliac spine. The volume of impingement decreased from 4.8 ± 4.5 cm3 after resection of the femoral head to 1.8 ± 1.6 cm3 and 1.2 ± 1.9 cm3 after release of the transverse and descending iliofemoral ligament, respectively.
CONCLUSIONS: With sequential soft-tissue releases, the femur mobility increased incrementally. However, the number of releases needed for each femur varied extensively between specimens. Most (10/14) femurs became accessible after the release of the ilio-femoral or ischio-femoral ligament.
摘要：
背景：在直接前路全髋关节置换术中，适当的暴露对于股骨的准备至关重要。这项研究的目的是通过实验测试和计算机模拟的结合，探索允许拉削股骨所需的最佳软组织释放。
方法：本研究包括十四个全身尸体标本。全髋关节置换术是通过直接前入路进行的，股骨内收20°和延伸20°。依次进行软组织释放，即,髂股横韧带,髂股降韧带,坐骨-股韧带,关节肌腱,和外部闭塞器。每次发布后，通过施加6Nm的外部旋转扭矩和120N的牵引力来评估股骨的活动性。随后，使用特定样本的模型和拉刀和手柄的模型，模拟每次释放后的拉刀通道，并分析了允许拉刀通过的释放。
结果：释放横向和下行髂股股韧带后的平均外旋增加了14.1°±6.1°和13.8°±5.3°。随着随后的软组织释放，轮换流动性逐渐增加，虽然影响有所下降。拉刀通道和骨盆之间的撞击主要在前上髂棘和前下髂棘。撞击体积从股骨头切除后的4.8±4.5cm3减少到释放横韧带和降韧带后的1.8±1.6cm3和1.2±1.9cm3。分别。
结论：对于连续的软组织释放，股骨活动能力逐渐增加。然而,每个股骨所需的释放次数在标本之间差异很大。大多数（10/14）股骨在lio股或坐骨股韧带释放后变得容易进入。
方法：本研究包括十四个全身尸体标本。全髋关节置换术是通过直接前入路进行的，股骨内收20°和延伸20°。依次进行软组织释放，即,髂股横韧带,髂股降韧带,坐骨-股韧带,关节肌腱,和外部闭塞器。每次发布后，通过施加6Nm的外部旋转扭矩和120N的牵引力来评估股骨的活动性。随后，使用特定样本的模型和拉刀和手柄的模型，模拟每次释放后的拉刀通道，并分析了允许拉刀通过的释放。
结果：释放横向和下行髂股股韧带后的平均外旋增加了14.1°±6.1°和13.8°±5.3°。随着随后的软组织释放，轮换流动性逐渐增加，虽然影响有所下降。拉刀通道和骨盆之间的撞击主要在前上髂棘和前下髂棘。撞击体积从股骨头切除后的4.8±4.5cm3减少到释放横韧带和降韧带后的1.8±1.6cm3和1.2±1.9cm3。分别。
结论：对于连续的软组织释放，股骨活动能力逐渐增加。然而,每个股骨所需的释放次数在标本之间差异很大。大多数（10/14）股骨在lio股或坐骨股韧带释放后变得容易进入。
