摘要
背景:髓内钉内固定是最常使用的闭合性股骨骨折固定技术,但需要结合外固定器来稳定开放性骨折,以保持旋转稳定性。因为作用于骨折的负载和固定装置的稳定性决定了骨断端相对位移,所以这种装置可能会影响手术肢体的生理负荷,进而对愈合产生影响。目的:比较不同刚度外固定器对小鼠骨折愈合组织形成效果及稳定性的作用,以寻求有效进行骨折固定治疗的新思路。方法:使用刚性和柔性外固定器(轴向刚度分别为17.9 和0.76 N/mm)用于稳定C57B/6 小鼠股骨中的0.5 mm截骨间隙。在术后21 d,通过三点弯曲试验、μCT 和组织形态计量分析2 种外固定器对小鼠骨折愈合的影响。结果与结论:①术后21 d,刚性固定组的弯曲刚度与对照完整骨相比降低了28.1%,柔性固定组的弯曲刚度与对照完整骨相比降低了18.9%,差异无显著性意义(P > 0.05);②柔性组的整个愈伤组织的体积较刚性组增加了1 倍多,并且最大直径也显著增大(P < 0.05);而骨体积分数明显减少(P < 0.05);③组织学分析显示,柔性组愈伤组织中的编织骨、层状骨和软骨的数量较刚性组显著增多(P < 0.05);④提示具有不同刚度的刚性或柔性外固定器均能诱导小鼠骨折处愈合组织形成,但是在柔性固定下愈合出现延迟。
BACKGROUND: Internal fixation with intramedullary nails is the most commonly used technique for closed femoral fractures, but external fixators are needed to stabilize open fractures in order to maintain rotational stability. Because the load acting on the fracture and the stability of the fixator determine the relative displacement of the broken end of the bone, the device may affect the physiological load of the operative limb, and then affect the healing. OBJECTIVE: To compare the effects of different stiffness external fixators on the formation and stability of fracture healing tissues in mice, in order to find a new way of effective fracture fixation treatment. METHODS: We introduced such a model using rigid and flexible external fixators with considerably different stiffness (axial stiffness of 17.9 and 0.76 N/mm, respectively). Both fixators were used to stabilize a 0.5 mm osteotomy gap in the femur of C57B/6 mice. Three-point bending tests,μCT, and histomorphometry demonstrated a different healing pattern after 21 days. RESULTS AND CONCLUSION:(1) Flexural stiffness of the rigid group was significantly reduced by 28.1% compared with the control intact bone, while flexural fixation reduced the flexural rigidity to 18.9% of the intact bone with no significant difference between the two groups after 21 days (P > 0.05).(2) Compared with the rigid group, the volume of the whole callus of the flexible group was more than doubled, and the maximum diameter also significantly increased (P < 0.05);while the bone volume fraction significantly decreased (P < 0.05).(3) Histological analysis showed that the numbers of braided bone, laminar bone and cartilage in the callus in the flexible group were significantly higher than those of the rigid group (P < 0.05).(4) The selected rigid and flexible fixations with different stiffness both lead to callus formation, but healing is delayed under flexible fixation.
作者
李宏元
王亮
Li Hongyuan;Wang Liang(Department of Orthopedics, Harrison International Peace Hospital, Hengshui 053000, Hebei Province, China;Department of Emergency, the Affiliated Hospital of Southwest Medical University, Luzhou 646000, Sichuan Province, China)
出处
《中国组织工程研究》
CAS
北大核心
2019年第28期4510-4515,共6页
Chinese Journal of Tissue Engineering Research
基金
河北省青年科技课题(20150437),项目负责人:李宏元~~
关键词
骨折
小鼠
外固定器
刚度
柔性
骨折愈合
稳定性
编织骨
层状骨
软骨
fractures
mice
external fixators
stiffness
flexibility
fracture healing
stability
braided bone
layered bone
cartilage
