Department of Traumatology, University of Newcastle and John Hunter Hospital, 2310 Newcastle, NSW,
Eur Cell Mater. 2017 Sep 11;34:99-107. doi: 10.22203/eCM.v034a07.
Morbidity associated with femur fractures in polytrauma patients is known to be high. The many unsolved clinical questions include the immunological effect of the fracture and its fixation, timing of fracture fixation, management of fracture non-union, effect of infection and critical size of bone defects. The aim of this study was to establish a clinically-relevant and reproducible animal model with regards to histological, biomechanical and radiological changes during bone healing. A custom-designed intramedullary nail with interlocking system (RabbitNail, RISystem AG, Davos Platz, Switzerland) was used for fixation, following femur fracture. New Zealand White rabbits were assigned to two groups: 1. closed fracture model (CF; non-survival model: n = 6, survival model: n = 3) with unilateral mid-shaft femur fracture created by blunt force; 2. osteotomy model (OT; survival model: n = 14) with unilateral transverse osteotomy creating femur fracture. There were no intraoperative complications and full-weight bearing was achieved in all survival rabbits. Significant periosteal reaction and callus formation were confirmed from 2 weeks postoperatively, with a significant volume formation (739.59 ± 62.14 mm3) at 8 weeks confirmed by micro-computed tomography (µ-CT). 2 months after fixation, there was no difference between the osteotomised and contralateral control femora in respect to the maximum torque (3.47 ± 0.35 N m vs. 3.26 ± 0.37 N m) and total energy (21.11 ± 3.09 N m × degree vs. 20.89 ± 2.63 N m × degree) required to break the femur. The data confirmed that a standardised internal fixation technique with an intramedullary nail for closed fracture or osteotomy produced satisfactory bone healing. It was concluded that important clinically-relevant studies can be conducted using this rabbit model.
多发创伤患者股骨骨折的发病率较高，其相关的许多临床问题尚未解决，包括骨折及其固定的免疫学效应、骨折固定的时机、骨折不愈合的处理、感染的影响和临界骨缺损大小等。本研究旨在建立一种具有临床相关性和可重复性的动物模型，以研究骨愈合过程中的组织学、生物力学和影像学变化。使用一种带有交锁系统的特制髓内钉（RabbitNail，RISystem AG，Davos Platz，瑞士）进行固定，之后造成股骨骨折。将新西兰白兔分为两组：1. 闭合骨折模型（CF；非存活模型：n = 6，存活模型：n = 3），通过钝力造成单侧股骨中段骨折；2. 截骨模型（OT；存活模型：n = 14），造成单侧横断骨折。所有存活的兔子均无术中并发症，且可完全负重。术后 2 周即可确认明显的骨膜反应和骨痂形成，8 周时通过微计算机断层扫描（µ-CT）确认有显著的体积形成（739.59 ± 62.14 mm3）。固定后 2 个月，在最大扭矩（3.47 ± 0.35 N m 对 3.26 ± 0.37 N m）和断裂股骨所需的总能量（21.11 ± 3.09 N m × 度对 20.89 ± 2.63 N m × 度）方面，截骨侧和对侧对照股骨之间没有差异。数据证实，使用髓内钉闭合骨折或截骨的标准化内固定技术可获得满意的骨愈合。因此，可以使用这种兔模型进行重要的临床相关研究。
