Zhou X M, Walker P S, Robertson D D
Orthopedic Biomechanics Laboratory, Brigham and Women's Hospital, Harvard Medical School, Boston, MA.
J Arthroplasty. 1990 Mar;5(1):71-82. doi: 10.1016/s0883-5403(06)80013-6.
A photoelastic coating method was used to study the strain patterns on the surface of the femur, before and after insertion of femoral stems. The anatomically shaped stems were press-fit without a collar, press-fit with a collar, and press-fit with proximal cementing to approximate a bone ingrowth situation. The strain patterns of the intact femurs were consistent with bending. The pattern changed considerably after stem insertion, probably due to the stiffening effect of the stems. Nevertheless, the collarless press-fit stem preserved 64% of the magnitude of the proximal medial strain. The collar restored the average to normal, but the surface strains varied because of the localized regions of contact between the collar and the bone. Proximal cementing gave results similar to those of the collarless press-fit. The press-fit stems often showed local patches of high strain, probably reflecting local endosteal contact points. Local high stresses at the level of the distal tip were seen in only a few instances.
采用光弹性涂层法研究股骨柄植入前后股骨表面的应变模式。解剖形状的柄分别采用无领压配、有领压配和近端骨水泥固定以模拟骨长入情况。完整股骨的应变模式与弯曲一致。柄植入后模式发生了很大变化，可能是由于柄的强化作用。然而，无领压配柄保留了近端内侧应变大小的64%。有领设计使平均值恢复正常，但由于柄与骨之间的局部接触区域，表面应变有所不同。近端骨水泥固定的结果与无领压配相似。压配柄常常显示出局部高应变区域，可能反映了局部骨内膜接触点。仅在少数情况下观察到远端尖端水平的局部高应力。
