摘要
目的研究骨质疏松性骨折愈合过程中骨痂生物力学性能与显微三维结构、Ⅰ型胶原面积、骨密度的改变规律及相关性。方法采用双侧卵巢切除术(ovariectomy,OVX)建立大鼠骨质疏松模型(OVX组),假手术组(Sham组)作为对照。两组均于术后10周通过大鼠右后肢胫骨中段截骨建立骨折内固定模型;骨折内固定模型建立后4、6、8、12周进行大鼠右后肢胫骨中段骨密度测定,术后6周及12周进行骨痂生物力学强度、Ⅰ型胶原面积及显微三维结构测定。结果两组中骨密度测量值在骨折内固定术后6周高于术后12周(P<0.05),而生物力学强度、Ⅰ型胶原面积和结构模型参数(structure model index,SMI)值在骨折内固定术后第12周时高于术后6周(P<0.05)。组间比较显示,骨折内固定术后6周与12周时OVX组的SMI值均明显低于Sham组(P<0.05)。结论在骨折愈合过程中,骨矿含量峰值出现时间早于胶原量与生物力学强度峰值出现时间,胶原的累积程度可独立于骨的矿盐沉积程度作为预测骨生物力学强度的一个指标。
Objective To study the changes of biomechanical properties and microarchitecture in callus during the healing process of osteoporotie fracture. Methods Ovariectomy （OVX） was performed on SD rats to establish osteoporotie rat model. Osteotomy was performed on both groups of rats with OVX and sham operations to establish bone fracture. Bone mineral density （BMD）, area of type Ⅰ collagen, biomeehanieal properties, and microarchitecture of the fractured bones during healing process were measured. Results The BMD of both groups of rats were significantly lower at the 12^th week than at the 6^th week after fracture （P〈0.05）. Both groups of rats had significantly higher biomeehanieal strength and area of type I collagen at the 12^th week than at the 6th week after fracture （P〈0.05）. The OVX group of rats had significantly lower structure model index （SMI） values than the sham group at both 6^th and 12^th week after fracture （P〈0.05）. Higher values of SMI appeared at the 12^th week than at the 6^th week in both groups of rats （P〈0.05）. Conclusion During the healing of fracture, the BMD of the newly-formed bone reaches its peak value at the 6^th week after fracture, which is earlier than the occurrence of peak biomeehanieal strength, area of type Ⅰ collagen, and SMI. Although the collagen and aggravation of mineral determine the biomeehanical properties, BMD by itself may not be able to determine the biomeehanical strength because of the change of the 3-D structure of the callus. The combination of collagen and microarchitecture may act as a factor that determines the biomechanical strength of callus independent of BMD.
出处
《四川大学学报（医学版）》
CAS
CSCD
北大核心
2010年第6期1016-1020,共5页
Journal of Sichuan University(Medical Sciences)
基金
国家自然科学基金(批准号30600622)资助
关键词
骨质疏松
骨折
三维结构
生物力学
Osteoporosis Fracture Microarchitecture Biomechanical properties
