Tanikake Yohei, Hayashi Koji, Ogawa Munehiro, Inagaki Yusuke, Kawate Kenji, Tomita Tetsuya, Tanaka Yasuhito
Department of Orthopedic Surgery, National Hospital Organization, Nara Medical Center, Nara, Japan.
Department of Orthopedic Surgery and Rehabilitation, Otemae Hospital, Chuo-ku, Osaka, Japan.
Arthroplast Today. 2016 Sep 15;2(4):157-163. doi: 10.1016/j.artd.2016.05.006. eCollection 2016 Dec.
A 72-year-old male patient underwent mobile-bearing posterior-stabilized total knee arthroplasty for osteoarthritis. He experienced a nontraumatic polyethylene tibial insert cone fracture 27 months after surgery. Scanning electron microscopy of the fracture surface of the tibial insert cone suggested progress of ductile breaking from the posterior toward the anterior of the cone due to repeated longitudinal bending stress, leading to fatigue breaking at the anterior side of the cone, followed by the tibial insert cone fracture at the anterior side of the cone, resulting in fracture at the base of the cone. This analysis shows the risk of tibial insert cone fracture due to longitudinal stress in mobile-bearing posterior-stabilized total knee arthroplasty in which an insert is designed to highly conform to the femoral component.
一名72岁男性患者因骨关节炎接受了活动平台后稳定型全膝关节置换术。术后27个月，他发生了非创伤性聚乙烯胫骨衬垫圆锥体骨折。胫骨衬垫圆锥体骨折表面的扫描电子显微镜检查表明，由于反复的纵向弯曲应力，韧性断裂从圆锥体后部向前部发展，导致圆锥体前部疲劳断裂，随后胫骨衬垫圆锥体在圆锥体前部骨折，最终导致圆锥体底部骨折。该分析表明，在活动平台后稳定型全膝关节置换术中，由于纵向应力存在胫骨衬垫圆锥体骨折的风险，这种置换术的衬垫设计为与股骨部件高度贴合。
