Bobyn J D, Cameron H U, Abdulla D, Pilliar R M, Weatherly G C
Clin Orthop Relat Res. 1982 Jun(166):301-12.
To study the effects of dynamic loading on biologic fixation, an unconstrained type of prosthesis was designed for total replacement of the knee joint of dogs. The femoral component was fabricated from cast cobalt-based surgical alloy. The tibial component was fabricated from surgical grade, ultra-high molecular weight, high density polyethylene. Both components were designed for initial stabilization at surgery by mechanical interlock with bone. In addition, the bone-interfacing surface of the metal component was made porous and the stem of the polymer component was grooved to permit the subsequent ingrowth of tissue. Knee arthroplasty was performed on a total of six beagles. The prostheses were monitored for periods of 20 months and demonstrated an overall excellent stability and functionality. Each tibial component became stabilized by the formation of a thin, surrounding shell of osseous tissue. Interposed between this bone and the implant was usually a thin layer of fibrous tissue, suggesting micromovement during loading. Each femoral component became solidly fixed by bone growth into the porous surface. The altered stress state in the region of the implant eventually resulted in reactive bone modeling, with both bone formation and resorption occurring along the length of the implant.
为研究动态载荷对生物固定的影响，设计了一种无约束型假体用于犬膝关节的全置换。股骨部件由铸造钴基外科合金制成。胫骨部件由外科级超高分子量高密度聚乙烯制成。两个部件均设计为在手术时通过与骨的机械互锁实现初始稳定。此外，金属部件的骨界面表面制成多孔状，聚合物部件的柄部开有凹槽，以允许组织随后向内生长。总共对六只比格犬进行了膝关节置换术。对假体进行了20个月的监测，结果显示总体稳定性和功能性极佳。每个胫骨部件通过形成一层薄的周围骨组织壳而实现稳定。在该骨与植入物之间通常夹有一层薄的纤维组织，表明加载过程中存在微动。每个股骨部件通过骨长入多孔表面而牢固固定。植入物区域改变的应力状态最终导致反应性骨重塑，沿植入物长度同时发生骨形成和吸收。
