Cloutier Luc P, Laflamme G Yves, Menard Jeremie, Petit Yvan
Mechanical Engineering Department, École de technologie supérieure, Montreal, Quebec, Canada; Laboratoire d'imagerie et d'orthopédie, Hôpital du Sacré-Cœur, Research Center, Montreal, Quebec, Canada.
Laboratoire d'imagerie et d'orthopédie, Hôpital du Sacré-Cœur, Research Center, Montreal, Quebec, Canada.
Clin Biomech (Bristol). 2014 Sep;29(8):930-5. doi: 10.1016/j.clinbiomech.2014.06.012. Epub 2014 Jun 26.
Greater trochanter fractures or osteotomies fixed with lateral plates still present high rates of complications. Unblocked greater trochanter anterior movement during hip extension might be a possible cause of failure. This study aimed to determine, under stair climbing conditions, the biomechanical behaviour of a greater trochanter fragment and the impact of an anterior locking plate on its migration.
Eighteen femurs paired from nine fresh frozen cadaveric specimens were tested on a quasi-dynamic stair climbing cycling test bench. Left and right sides with greater trochanter fractures were randomly fixed either with an antero-lateral locking plate or with a lateral locking plate. Migrations, defined as the remaining movements of the unloaded greater trochanter fragment, were measured for all 18 femurs.
During hip extension, multi-directional greater trochanter fragment movements occurred and showed a back-and-forth anterior rotation. The lateral locking plate failed due to greater trochanter fragment rotation around the superior axis and anterior translation. The antero-lateral locking plate significantly reduced greater trochanter anterior migration (-0.9 mm ± 1.6) compared to the lateral locking plate (9.6 mm ± 9.5).
Hip extension provides a plausible explanation for the high rate of post-operative failures of greater trochanter fixations. An antero-lateral locking plate represents an efficient surgical alternative counteracting the multi-directional greater trochanter movements occurring during hip extension.
用外侧钢板固定的大转子骨折或截骨术仍存在较高的并发症发生率。髋关节伸展时大转子向前移动不受阻碍可能是失败的一个潜在原因。本研究旨在确定在爬楼梯条件下，大转子碎片的生物力学行为以及前侧锁定钢板对其移位的影响。
从9个新鲜冷冻尸体标本中配对取出18根股骨，在准动态爬楼梯循环试验台上进行测试。大转子骨折的左右两侧随机用前外侧锁定钢板或外侧锁定钢板固定。测量所有18根股骨的移位情况，移位定义为卸载的大转子碎片的剩余移动量。
在髋关节伸展过程中，大转子碎片出现多方向移动，并表现出前后旋转。外侧锁定钢板因大转子碎片绕上轴旋转和向前平移而失效。与外侧锁定钢板（9.6 mm±9.5）相比，前外侧锁定钢板显著减少了大转子的前向移位（-0.9 mm±1.6）。
髋关节伸展为大转子固定术后高失败率提供了一个合理的解释。前外侧锁定钢板是一种有效的手术替代方案，可抵消髋关节伸展过程中发生的大转子多方向移动。
