Maisonneuve骨折下胫腓分离固定的生物力学研究

A biomechanical study of stabilization of the syndesmosis in the Maisonneuve fracture

目的 比较两孔锁定钢板固定下胫腓联合是否比传统螺钉固定更具生物力学优势.方法 选用12具防腐处理的小腿标本,模拟制造不稳定Maisonneuve骨折,随机分为两孔锁定钢板组和螺钉组.进行模拟步态的循环试验以及扭转失败的生物力学测试,测量下胫腓联合增宽、扭矩和角度.结果 两组内固定方法均能较好控制下胫腓联合增宽,钢板组稍占优势,但差异无统计学意义（0.07 mm比0.06 mm,P＞0.05）.钢板组和螺钉组的扭矩测量两组间差异有统计学意义,平均扭矩分别为40.48、20.17 Nm（P ＜0.05）.结论两孔锁定钢板比两枚3.5mm四皮质螺钉固定下胫腓联合作用强.

Objective To determine whether a two-hole locking plate has biomechanical advantages over conventional screw stabilizsation of the syndesmosis in this injury pattern.Methods Six pairs of embalmed human cadaver lower legs were prepared to simulate an unstable Maisonneyve fracture.Each limb had randomly selected to receive either a 3.5 mm distal fibula locking plate with two 3.5 mm screws,or two parallel quadricortical 3.5 mm screws.The limbs were then mounted on a servo-hydraulic testing rig and axially loaded for 1200 cycles.Each limb was then externally rotated until failure occurred.Fibula diastasis,torque and angle were measured.Results Both constructs effectively stabilized the syndesmosis during the cyclical loading （0.07 mm vs.0.06 mm,P ＞ 0.05）.However the locking plate group demonstrated greater resistance to torque than quadricortical screw fixation （40.48 Nm vs.20.17 Nm,P＜0.05）.Conclusion A two-hole locking plate provides significantly greater stability of the syndesmosis to torque than 3.5 mm quadricortical fixation.