Brown T D, Pedersen D R, Baker K J, Brand R A
Department of Orthopaedic Surgery, University of Iowa, Iowa City 52242-1008.
J Bone Joint Surg Am. 1993 Sep;75(9):1358-67. doi: 10.2106/00004623-199309000-00011.
We employed an anatomically realistic three-dimensional finite-element model to explore several biomechanical variables involved in coring or bone-grafting of a segmentally necrotic femoral head. The mechanical efficacy of several variants of these procedures was indexed in terms of their alteration of the stress:strength ratio in at-risk necrotic cancellous bone. For coring alone, the associated structural compromise was generally modest, provided that the tract did not extend near the subchondral plate. Cortical bone-grafting was potentially of great structural benefit for femoral heads in which the graft penetrated deeply into the superocentral or lateral aspect of the lesion, ideally with abutment against the subchondral plate. By contrast, central or lateral grafts that stopped well short of the subchondral plate were contraindicated biomechanically because they caused marked elevations in stress on the necrotic cancellous bone. Calculated levels of stress were relatively insensitive to variations in the diameter of the graft.
我们采用了一个解剖学上逼真的三维有限元模型，以探究与节段性坏死股骨头的钻孔或骨移植相关的几个生物力学变量。这些手术的几种变体的力学效能，根据其对高危坏死松质骨应力：强度比的改变来衡量。对于单纯钻孔而言，只要通道不延伸至软骨下骨板附近，相关的结构破坏通常较小。皮质骨移植对于股骨头可能具有很大的结构益处，即移植骨深入病变的中央上方或外侧，理想情况下与软骨下骨板贴合。相比之下，在软骨下骨板之前就终止的中央或外侧移植在生物力学上是禁忌的，因为它们会导致坏死松质骨上的应力显著升高。计算得出的应力水平对移植骨直径的变化相对不敏感。
