Van Lenthe G H, de Waal Malefijt M C, Huiskes R
Biomechanics Section, Institute of Orthopaedics, University of Nijmegen, The Netherlands.
J Bone Joint Surg Br. 1997 Jan;79(1):117-22. doi: 10.1302/0301-620x.79b1.6808.
Inadequate bone stock is often found in revision surgery of femoral components of total knee replacements. Our aim was to test the hypothesis that these remodelling patterns can be explained by stress shielding, and that prosthetic bonding characteristics affect maintenance of bone mass. We made a three-dimensional finite-element model of an average male femur with a cemented femoral knee component. This model was integrated with iterative remodelling procedures. Two extreme prosthetic bonding conditions were analysed and gradual changes in bone density were calculated. The long-term bone loss under the femoral knee component resembled clinical findings which confirms the hypothesis that stress shielding can cause distal femoral bone loss. Our study predicts, contrary to clinical findings, that an equilibrium situation is not reached after two years, but that bone resorption may continue. This hidden bone loss may be so drastic that large reconstructions are needed at the time of revision.
在全膝关节置换股骨部件的翻修手术中，常常会发现骨量不足的情况。我们的目的是检验以下假设：这些重塑模式可以通过应力遮挡来解释，并且假体的粘结特性会影响骨量的维持。我们建立了一个带有骨水泥固定股骨膝关节部件的平均男性股骨的三维有限元模型。该模型与迭代重塑程序相结合。分析了两种极端的假体粘结情况，并计算了骨密度的逐渐变化。股骨膝关节部件下方的长期骨质流失与临床结果相似，这证实了应力遮挡会导致股骨远端骨质流失的假设。与临床结果相反，我们的研究预测，两年后不会达到平衡状态，而是骨吸收可能会继续。这种隐藏的骨质流失可能非常严重，以至于在翻修时需要进行大型重建。
