肱骨髁上骨折张力带内固定的生物力学评价

Biomechanical evaluation of internal fixation on supracondylar fracture of humerus

目的为了解决肱骨髁上骨折治疗方法多样性和繁杂性,进行的生物力学测试及临床随访结果分析,寻找一种最佳治疗方案。方法采用经防腐处理的儿童离体上肢10具,制成肱骨髁上骨折模型,钢针张力带,交叉钢针,牵引固定,夹板固定,石膏固定,经纵向及偏轴加载后测出各种固定时骨折的稳定性及内固定物的抗弯及抗旋转强度;同时,总结1984/2003应用保守及手术治疗的肱骨髁上骨折患者648例,分析治疗效果及并发症的发生率。结果张力带钢针最稳定,承载最大,其次是交叉钢针、牵引、石膏夹板固定最差。在纵向加载(抗弯)能力中,钢针张力带内固定位移最小交叉钢针次之,经统计学检验,P<0.001,在偏轴加载(抗旋转)能力中,交叉钢针优于张力带钢针单明显优于其他固定P<0.001临床随访病例中张力带钢针优良率最高,达94.3%,其次是交叉钢针,牵引,石膏,夹板,此与力学结果相符。结论对于手术的患者,应首选钢针张力带内固定,因其结构稳固,具有加压作用,功能恢复和骨折愈合同步进行。闭式贯穿钢针内固定功能恢复时间较长,亦是首选的治疗方法,牵引,石膏夹板稳定性差,骨折易再移位,选择应慎重。

AIM:To solve the diversity and complicity of the therapy for supracondylar fracture of the humerus(SFH) by biomechanical study and retrospective analysis, in order to find the best therapy.METHODS:Ten embalmed child's arms were taken for SFH, which were made into the models of condyle of humerus and fixed with tension band pin, cross pin, splint, plaster and traction. All humerus were measured for vertical force and rotated force. Meanwhile, restrospective analysis on 648 cases of SFH was done for studying the therapentic effect and complication. RESULTS:Tension band pin was most stable with more bear, the following group was cross pin, traction. Plaster and splint was least unstable. The statistical results indicated that tension band provided more stability than cross pin(P< 0.001),but the rotation resistance of cross pin was stronger than tension band pin (P< 0.001).The follow up results indicated that the excellent good rate of the patients with tension band pin was the highest (94.3%), the following group was cross pin, traction plaster and splint, which was corresponded with biomechanical study. CONCLUSION: Tension band pin should be an initial choice for SFH,stable structure and compression are important for the recovery of function and the union. Percutaneous cross pin fixation can be a routine choice but need longer time for the recovery of founction. Because of the unstable and higher rate of redislocation, traction,plaster and splint should be selected cautiously for SFH.