螺钉与钢板固定骨质疏松患者后踝骨折在模拟正常步态周期中的生物力学研究  

Biomechanical study of screw and plate fixation of a posterior malleolar fracture for osteoporosis patients in a simulation of the normal gait cycle

作　　者：王旭[1] 尹建文[1] 耿翔[1] 王晨[1] 陈立[1] 张超[1] 黄加张[1] 马昕[1] 

机构地区：[1]复旦大学附属华山医院,上海200040

出　　处：《中华骨科杂志》2017年第22期1407-1415,共9页Chinese Journal of Orthopaedics

基　　金：上海市科委科研计划项目（152R1405500）;国家自然科学基金项目（81572176）

摘　　要：目的 利用模拟步态周期的疲劳加载系统与空间运动捕捉系统,通过比较螺钉与钢板固定的骨质疏松患者后踝骨折的生物力学强度,为骨质疏松患者后踝骨折的内固定选择提供理论依据.方法 72具骨质疏松下肢标本,通过后踝截骨获得Haraguchi Ⅰ型后踝骨折模型,随机分成应用两枚4.0 mm钛合金半螺纹空心螺钉平行自后向前固定组（螺钉组）和应用后踝解剖钢板固定组（钢板组）,每组36具.根据矢状位骨折块面积与胫骨远端关节面总面积的比值S,每组又分为3个小组分别记为螺钉A组、钢板A组、螺钉B组、钢板B组、螺钉C组、钢板C组;S螺钉A组·钢板A组=1/4,S螺钉B组-钢板B组=l/3,S螺钉c组-钢板C组=l/2.根据后踝骨折块的高度H,每组再分为a、b两组,HA组=19.3 mm,Hb组=39 mm.模拟步态周期中4种踝关节位置进行力学加载：①背伸12°,3.2倍体重;②背伸5°,3倍体重;③中立位,3.6倍体重;④跖屈15°,4.5倍体重.疲劳加载系统反复加载,利用空间运动捕捉系统测量加载终末期骨折块的位移.结果 模拟踝关节背伸12°与跖屈15°位置,螺钉组和钢板组模型无论后踝骨折块大小与高度,位移均存在统计学差异,且螺钉组位移大于钢板组.而在踝关节背伸5°位置加载,螺钉Ca组和钢板Ca组骨折块位移分别为（0.47±0.11） mm和（0.51±0.07） mm,两者间无统计学差异;螺钉Ab组和钢板Ab骨折块位移分别为（0.76±0.13） mm和（0.63±0.10） mm,两组间无统计学差异,其余各组均存在统计学差异,且螺钉组位移大于钢板组.在中立位,螺钉Bb组和钢板Bb组加载后骨折块位移分别为（1.46±0.16） mm和（1.58±0.18） mm,两者间无统计学差异,其余各组均存在统计学差异,且螺钉组位移大于钢板组.结论 对于大部分骨质疏松患者的后踝骨折,后侧解剖钢板可以提供更坚强的固定;但骨折块面积或高度过大时,两种固定方法均不能提供坚强的固定.Objective Purpose of this research is to biomechanically compare the screw-fixed and plate-fixed posterior malleolus fracture in osteoporosis patients with fatigue loading system and space motion system in simulation gait cycle,and to give a theory evidence on how to choose an internal fixation in osteoporosis patients with posterior malleolus fracture.Methods 72 osteoporotic cadaveric lower limbs were prepared to simulate Haraguchi Ⅰ posterior malleolus fracture and randomized into 2 groups with 36 each.Screw group were fixed with 2 paralleled 4.0 mm titanium partial thread cancellous screws from posterior to anterior.Plate group were fixed with plate.Based on the ratio of fracture area on sagittal plane to distal tibial articular surface （S）,the two groups were subdivided into three subgroups,named as screw group A,plate group A,screw group B,plate group B,screw group C,plate group C.S （screw group A,plate group A）=l/4;S （screw group B,plate group B）=1/3;S （screw group C,plate group C）=1/2.According to the height of fracture fragments,these 6 subgroups were further divided into subgroup ＂a＂ with height 19.3mm and subgroup ＂b＂ with height 39 mm.Furthermore,4 different conditions of gait cycle were simulated as follows：1） specimen was loaded with 3.2 body weight （BW） at dorsiflexion angle of 12°;2） Start-up phase：dorsiflexion angle of 5°,3 BW;3） neutral position,3.6 BW;4） maximum plantar flexion,angle of 12°,4.5 BW.At the end of repeated loading,the displacement of fracture fragment was measured with space motion system.Results At dorsiflexion 12° and plantar flexion 15°,there was a significant difference of displacement between screw and plate group with a larger displacement in screw group,whatever S or H was.When ankle was at dorsiflexion of 5°,the displacement showed significant difference between screw group Aa and plate group Aa,screw group Ba and plate group Ba,screw group Bb and plate group Bb,screw group Cb and plate group Cb,with a larger displacement in s

关 键 词：踝损伤 骨质疏松 骨折固定术 内 生物力学 

分 类 号：R580[医药卫生—内分泌] R687.3[医药卫生—内科学]