Mäkinen Tatu J, Dhotar Herman S, Fichman Simcha G, Gunton Matthew J, Woodside Mitchell, Safir Oleg, Backstein David, Willett Thomas L, Kuzyk Paul R T
Mount Sinai Hospital, Division of Orthopaedic Surgery, University of Toronto, 600 University Avenue, Toronto, Ontario, M5G 1X5, Canada,
Int Orthop. 2015 Sep;39(9):1737-42. doi: 10.1007/s00264-015-2764-0. Epub 2015 Apr 16.
The aim of this study was to determine the biomechanical properties of four fixation options for periprosthetic supracondylar femoral fractures.
Fourth-generation composite femurs were implanted with a posterior-stabilizing femoral component of total knee arthroplasty. All femurs were osteotomized to produce a AO/OTA 33-A3 fracture pattern and four different constructs were tested: (1) non-locking plate; (2) polyaxial locking plate; (3) intramedullary fibular strut allograft with polyaxial locking plate; (4) retrograde intramedullary nail. The composite femurs underwent non-destructive tests to determine construct stiffness in axial and torsional cyclic loading. The final testing consisted of quasi-static axial loading until failure.
Under cyclic torsional loading, the retrograde intramedullary nail was less stiff than non-locking plate, polyaxial locking plate and intramedullary fibular strut allograft with polyaxial locking plate (p = 0.046). No differences were detected in cyclic axial loading between the different constructs. During quasi-static axial loading to failure, the intramedullary nail achieved the highest axial stiffness while the non-locking plate showed the lowest (p = 0.036).
The intramedullary fibular strut allograft with polyaxial locking plate did not prove to be significantly better to the polyaxial locking plate only in a periprosthetic distal femur fracture model.
本研究旨在确定四种用于假体周围股骨髁上骨折固定方法的生物力学特性。
在第四代复合股骨上植入全膝关节置换的后稳定型股骨组件。所有股骨均行截骨术以形成AO/OTA 33-A3骨折模式，并测试四种不同的固定结构：（1）非锁定钢板；（2）多轴锁定钢板；（3）带多轴锁定钢板的同种异体腓骨髓内支撑物；（4）逆行髓内钉。对复合股骨进行无损测试，以确定轴向和扭转循环加载时固定结构的刚度。最终测试包括直至失效的准静态轴向加载。
在循环扭转加载下，逆行髓内钉的刚度低于非锁定钢板、多轴锁定钢板和带多轴锁定钢板的同种异体腓骨髓内支撑物（p = 0.046）。不同固定结构在循环轴向加载方面未检测到差异。在准静态轴向加载至失效过程中，髓内钉达到最高轴向刚度，而非锁定钢板最低（p = 0.036）。
在假体周围股骨远端骨折模型中，带多轴锁定钢板的同种异体腓骨髓内支撑物并不比单纯的多轴锁定钢板显著更好。
