Ivarsson I, Gillquist J
Department of Orthopaedic Surgery, University Hospital, Linkoping, Sweden.
Clin Orthop Relat Res. 1992 Jun(279):194-200.
The strain distribution in the proximal tibia in seven human autopsy specimens was investigated with strain-gauge rosettes attached on the medial proximal aspect of the tibia. The strains measured were about the same on the proximal bone and on the bone in the metaphysis. The direction of the minimal principal strain (compression) was about 45 degrees counterclockwise (left knee). After insertion of a unicompartmental prosthesis medially, a non-constrained prosthesis with a loose meniscus-bearing and a constrained prosthesis, the tensile strain was about four times higher in the most anteromedial gauge. No significant differences were found between prostheses. Tests were also performed with the two prostheses inserted into three plastic models. The constrained prosthesis was more sensitive to outward rotation of tibia versus femur, which made the femoral component climb up the slope of the tibial component and caused a marked change in the strain distribution compared to loading in the neutral position. With the other prosthesis, a malpositioning of the tibial component medially caused the meniscus bearing to lie close to the medial rim of the tibial component. An external rotation of tibia then made the system constrained and dramatically changes the strain distribution.
使用附着在胫骨近端内侧的应变片花环，对7个尸体标本的胫骨近端应变分布进行了研究。在近端骨和干骺端骨上测得的应变大致相同。最小主应变（压缩）方向逆时针约45度（左膝）。在内侧植入单髁假体、带松弛半月板的非限制性假体和限制性假体后，最前内侧应变片处的拉伸应变约高四倍。假体之间未发现显著差异。还对插入三个塑料模型中的两种假体进行了测试。与在中立位置加载相比，限制性假体对胫骨相对于股骨的向外旋转更敏感，这使得股骨部件爬上胫骨部件的斜坡，并导致应变分布发生显著变化。使用另一种假体时，胫骨部件向内侧的位置不当会导致半月板衬垫靠近胫骨部件的内侧边缘。胫骨的外旋随后使系统受到限制，并显著改变应变分布。
