普通加压钢板与锁定钢板内固定修复老年复杂性肱骨干中下段骨折的生物力学比较

Comparison of biomechanics of common compression plate and locking plate fixation for middle and lower complex humeral shaft fracture in the elderly

背景:肱骨干中下段骨折是临床常见上肢骨折,在老年人群中发生率及复发率都较高,然而目前缺乏疗效理想的修复方法。目的:对比分析普通加压钢板与锁定钢板内固定修复老年复杂性肱骨干中下段骨折的生物力学差异。方法:筛选30对防腐老年人肱骨标本,人工制造肱骨中下段骨折模型。将同一个体来源的2个肱骨完整取下随机分为2组,分别采用锁定钢板和普通加压钢板固定,并通过实验力学模型检测钢板和标本分别在压缩、弯曲和扭转3种不同负载方式下的位移值和扭转角度,分析并比较2组数据。结果与结论:1所有标本在排除相关因素影响后,选取其中骨密度高、质量优等的标本进行实验;2锁定钢板在轴向负荷为500 N,弯曲负荷为7.0 N·m,扭转负荷为3 N·m以内的压缩、弯曲、扭转等条件下,其应变均小于普通加压钢板组(P<0.05),锁定钢板组肱骨标本的相对位移在以上加载方式下也均小于普通加压钢板组(P<0.05);3以上数据表明,锁定钢板有较好的抗压、抗弯曲和抗扭转性能,能保证骨折连接处的稳定和一体性。

BACKGROUND：The lower and middle humeral shaft fractures are common upper limb fractures.Incidence rate and recurrence rate were high in the elderly population.However,there is a lack of a method with ideal curative effect.OBJECTIVE：To compare and analyze the biomechanical differences between common compression plate and locking plate fixation in the repair of middle and lower complex humeral shaft fracture in the elderly.METHODS：30 pairs of antiseptic elderly humerus specimens were selected to make models of middle and lower humeral shaft fracture.Two humeri from the same individual were randomly assigned to two groups,and subjected to locking plate and common compression plate fixation.Experimental mechanics models were used to determine displacement and torsion angle under compression,bending and torsion.Data were analyzed and compared between the two groups.RESULTS AND CONCLUSION：（1） After exclusion of relevant factors,specimens with high bone density and excellent quality were selected from all specimens.（2） Under axial load of 500 N,the bending load of 7.0 N·m and torsional load of 3 N·m or less,the strain was smaller in locking plate group than in common compression plate group under compression,bending and torsion（P〈 0.05）.Relative displacement under the above loading was smaller in locking plate group than in common compression plate group（P〈 0.05）.（3） Above data suggested that locking plate has good compressive,flexural and torsional rigidity,can ensure the stability and integrity of the fracture connection.