摘要目的:观察三维步态分析技术结合OpenSim软件预测脑性瘫痪患儿马蹄足畸形的踝关节最佳背屈角度对其跟腱延长手术后步态的影响。方法:选取符合入选和排除标准的脑性瘫痪合并马蹄足畸形患儿9例，均给予跟腱延长术。术前完善9例患儿骨盆和下肢的CT重建图像，结合手术前的步态分析数据构建OpenSim模拟动图，在软件内模拟跟腱止点变化曲线图，通过曲线图，对9例患儿进行术前踝关节最佳背屈角度预测，然后依据该角度对其进行跟腱延长手术。手术前和跟腱延长手术12个月后(手术后)，应用三维步态分析系统对9例患儿进行三维步态分析，收集患儿的步态时空参数、运动学参数和动力学参数(患侧最大地面反作用力)，并记录手术前、后的踝关节最大背屈角度。结果:跟腱延长手术前，脑性瘫痪儿童马蹄足畸形预测踝关节最佳背屈角度8~12°，平均(10.1±1.2)°。手术后，患者的患侧步长、步幅长度、节奏、速度和患侧步时较手术前均显著改变，差异均有统计学意义( P<0.05)。手术后，患者的支撑相骨盆最大前倾角度、支撑相踝关节最大背屈角度和摆动相踝关节最大跖屈角度较手术前均显著改变，差异均有统计学意义( P<0.05)。手术12个月后，9例患儿均未见马蹄畸形复发和矫正过度并发症的发生。 结论:三维步态分析技术结合OpenSim软件可对脑性瘫痪儿童马蹄足畸形跟腱止点变化进行模拟，并在手术前预测其最佳的背屈角度进而指导手术，同时三维步态分析技术结合OpenSim软件还可对手术前和手术后进行量化评价，可为后续的康复治疗提供参考。

abstractsObjective:To observe any effect of ankle dorsiflexion angle on the gait of children with cerebral palsy (CP) after Achilles tendon lengthening surgery.Methods:Nine children with CP and equinus foot deformity were given Achilles tendon lengthening surgery. Reconstruction images of their pelvises and lower limbs were collected before the surgery and used to construct OpenSim simulations. Gait analysis data were also recorded before the surgery. The curve of changes to the Achilles tendon insertion was simulated in the software to determine the optimum angle of ankle dorsiflexion, and that guided the Achilles tendon extension surgery. The 3D gait analysis was repeated 12 months after the surgery to compare the spatiotemporal, kinematic and dynamic parameters (especially maximum ground reaction force on the affected side). The maximum dorsiflexion angles of the ankle joint before and after surgery were also recorded.Results:Before the surgery the dorsiflexion angles ranged from 8 to 12°, with an average of (10.1±1.2)°. After the surgery, significant changes were observed in the stride length, rhythm, speed and stride time of the affected side, as well as the maximum forward angle of the supported pelvis, the maximum dorsiflexion angle of the supported ankle and the maximum plantar flexion angle of the swinging ankle. Twelve months after the surgery, no recurrence of horseshoe malformation or over-correction complications were found in any of the 9 patients.Conclusions:3D gait analysis technology combined with OpenSim software can simulate the changes in Achilles tendon length needed by children with cerebral palsy. The optimum ankle dorsiflexion angle can be predicted pre-operatively and the simulation can also guide the operation. This technique also offers pre-and post-operative quantitative evaluation to provide references for subsequent rehabilitation treatment.