Differential fracture healing resulting from fixation stiffness variability: a mouse model
Differential fracture healing resulting from fixation stiffness variability: a mouse model
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DOI：
10.1007/s00776-011-0051-5
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发表时间：
2011-05-01
影响因子：
1.7
通讯作者：
Silva, Matthew J.
中科院分区：
文献类型：
--
作者：
Gardner, Michael J.;Putnam, Sara M.;Silva, Matthew J.
局部力学环境和骨折愈合之间相互作用的机制尚不清楚。我们开发了一个小鼠股骨骨折模型，植入不同的刚度，并假设，差异骨折愈合将导致股骨干骨折在70只小鼠，并与髓内钉制成的钨（杨氏模量= 410 GPa）或铝（杨氏模量= 70 GPa）进行治疗。然后在2或5周时处死小鼠。使用标准microCT、组织学和生物力学方法分析骨折骨痂。2周时，铝组骨痂体积显著大于钨组（61.2 vs. 40.5 mm（3），p = 0.016），但两组骨痂内的骨体积无差异（13.2 vs. 12.3 mm（3））。钨组的骨痂在力学测试中更硬（18.7 vs. 9.7 N/mm，p = 0.01）。骨痂中的软骨百分比在铝组中为31.6%，在钨组中为22.9%（p = 0.40）。在5周时，任何愈合的股骨之间都没有差异。在这项研究中，不同刚度的骨折植入物导致小鼠骨折模型中不同的骨折愈合。用更硬的植入物治疗的骨折在2周时愈合更快，但仍通过骨痂形成愈合。虽然这一概念以前已经有了很好的记录，但这种特殊的模型可能是一种有价值的研究工具，用于研究改变固定刚度的愈合后果，这可能会深入了解骨折和骨不连的发病机制和理想治疗方法。
The mechanisms underlying the interaction between the local mechanical environment and fracture healing are not known. We developed a mouse femoral fracture model with implants of different stiffness, and hypothesized that differential fracture healing would result.Femoral shaft fractures were created in 70 mice, and were treated with an intramedullary nail made of either tungsten (Young's modulus = 410 GPa) or aluminium (Young's modulus = 70 GPa). Mice were then sacrificed at 2 or 5 weeks. Fracture calluses were analyzed using standard microCT, histological, and biomechanical methods.At 2 weeks, callus volume was significantly greater in the aluminium group than in the tungsten group (61.2 vs. 40.5 mm(3), p = 0.016), yet bone volume within the calluses was no different between the groups (13.2 vs. 12.3 mm(3)). Calluses from the tungsten group were stiffer on mechanical testing (18.7 vs. 9.7 N/mm, p = 0.01). The percent cartilage in the callus was 31.6% in the aluminium group and 22.9% in the tungsten group (p = 0.40). At 5 weeks, there were no differences between any of the healed femora.In this study, fracture implants of different stiffness led to different fracture healing in this mouse fracture model. Fractures treated with a stiffer implant had more advanced healing at 2 weeks, but still healed by callus formation. Although this concept has been well documented previously, this particular model could be a valuable research tool to study the healing consequences of altered fixation stiffness, which may provide insight into the pathogenesis and ideal treatment of fractures and non-unions.