Compressive fatigue and fracture toughness behavior of injectable, settable bone cements.
Compressive fatigue and fracture toughness behavior of injectable, settable bone cements.
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DOI：
10.1016/j.jmbbm.2015.07.027
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发表时间：
2015-11
影响因子：
3.9
通讯作者：
Nyman JS
中科院分区：
文献类型：
--
作者：
Harmata AJ;Uppuganti S;Granke M;Guelcher SA;Nyman JS
用于修复负重胫骨平台骨折的骨移植物经常经历循环载荷，因此需要骨移植替代物来防止固定失败和随后的发病率。然而，可吸收移植物优化与天然骨的结构相容性所需的特定机械性能尚未确定。虽然准静态测试用于评估承重能力，但单独的抗压强度是体内性能的不良指标。在本研究中，我们研究了在重新屈服于与承重断裂相关的循环载荷的条件下，界面粘结对材料性能的影响。在生理相关应力（5-30 MPa）下，将由未改性（U-）或聚己内酯表面改性（PCL-）45 S5生物活性玻璃（BG）颗粒制成的聚氨酯（PUR）复合材料的动态压缩疲劳性能与市售硫酸钙和磷酸钙基（CaS/P）骨水泥进行了比较。在较高应力水平下，PCL-BG/聚合物复合材料的抗疲劳性上级U-BG和CaS/P的抗疲劳性，对于与模量、蠕变和最大位移相关的每个疲劳失效标准，与人骨小梁相当。稳态蠕变和损伤累积发生在PCL-BG/PUR和CaS/P骨水泥的疲劳寿命期间，而U-BG/PUR的蠕变主要发生在低载荷循环次数下。从裂纹扩展测试，断裂韧性或裂纹扩展阻力是显着高于PCL-BG复合材料比其他材料。最后，疲劳和断裂韧性性能介于松质骨和皮质骨之间。这些发现突出了PCL-BG/聚氨酯复合材料作为承重骨移植物的潜力。
Bone grafts used to repair weight-bearing tibial plateau fractures often experience cyclic loading, and there is a need for bone graft substitutes that prevent failure of fixation and subsequent morbidity. However, the specific mechanical properties required for resorbable grafts to optimize structural compatibility with native bone have yet to be established. While quasi-static tests are utilized to assess weight-bearing ability, compressive strength alone is a poor indicator of in vivo performance. In the present study, we investigated the effects of interfacial bonding on material properties under conditions that re-capitulate the cyclic loading associated with weight-bearing fractures. Dynamic compressive fatigue properties of polyurethane (PUR) composites made with either unmodified (U-) or polycaprolactone surface-modified (PCL-) 45S5 bioactive glass (BG) particles were compared to a commercially available calcium sulfate and phosphate-based (CaS/P) bone cement at physiologically relevant stresses (5–30 MPa). Fatigue resistance of PCL-BG/polymer composite was superior to that of U-BG and CaS/P at higher stress levels for each of fatigue failure criteria, related to modulus, creep, and maximum displacement, and was comparable to human trabecular bone. Steady state creep and damage accumulation occurred during the fatigue life of the PCL-BG/PUR and CaS/P cement, whereas creep of U-BG/PUR primarily occurred at a low number of loading cycles. From crack propagation testing, fracture toughness or resistance to crack growth was significantly higher for the PCL-BG composite than for the other materials. Finally, the fatigue and fracture toughness properties were intermediate between those of trabecular and cortical bone. These findings highlight the potential of PCL-BG/polyurethane composites as weight-bearing bone grafts.