Clinic for Orthopedic and Trauma Surgery, University Hospital Heidelberg, Heidelberg, Germany.
Orthopedic University Hospital Friedrichsheim, Frankfurt/Main, Germany.
Dev Med Child Neurol. 2019 Jul;61(7):791-797. doi: 10.1111/dmcn.14097. Epub 2018 Nov 25.
To evaluate short-term (1y postoperatively; E1) and long-term (at least 4y postoperatively; E2) changes in hamstring muscle-tendon length (MTL) and lengthening velocity after hamstring lengthening in children with bilateral cerebral palsy (CP).
Three-dimensional gait analysis was performed in 19 children (16 males, 3 females; 36 limbs; mean age at surgery 9y [SD 3y]; range 6-10y) with flexed knee gait, preoperative ankle dorsiflexion lower than 20 degrees, and CP before bilateral hamstring lengthening (E0), at E1 and E2. Hamstring MTL (normalized by leg length) and velocity were assessed via OpenSim software.
MTL increased from E0 to E1 (p=0.004) and decreased from E1 to E2 (p<0.020). Hamstring lengthening velocity did not change. In the subgroup with short, not slow hamstrings, the increase in MTL was maintained at E2.
Hamstring lengthening is an efficient procedure to lengthen short and/or slow hamstrings short-term. The desired outcome with maintenance of the postoperative changes in hamstring MTL is only achieved for preoperatively short, not slow hamstrings.
Surgical hamstring lengthening can be confirmed via musculoskeletal modelling in OpenSim software. Surgical hamstring lengthening in cerebral palsy does not change hamstring lengthening velocity. Short, not slow hamstrings present a long-lasting muscle-tendon length (MTL) increase after hamstring lengthening. Changes in MTL after hamstring lengthening cannot be maintained for slow hamstrings. MTL does not change after hamstring lengthening for neither short nor slow hamstrings.
评估双侧脑瘫儿童（CP）行腘绳肌延长术后 1 年（E1）和至少 4 年（E2）时腘绳肌-肌腱长度（MTL）和延长速度的短期和长期变化。
对 19 名（男 16 名，女 3 名；36 条肢体；手术时平均年龄 9 岁[标准差 3 岁]；6-10 岁）膝关节弯曲步态、术前踝关节背屈小于 20 度且双侧腘绳肌延长术前有 CP 的儿童进行三维步态分析。腘绳肌 MTL（通过腿长归一化）和速度通过 OpenSim 软件进行评估。
MTL 从 E0 到 E1 增加（p=0.004），从 E1 到 E2 减少（p<0.020）。腘绳肌延长速度没有变化。在短而不慢的腘绳肌的亚组中，MTL 的增加在 E2 时保持。
腘绳肌延长术是一种有效延长短而慢的腘绳肌的短期方法。仅在术前短且不慢的腘绳肌中，才能达到维持术后腘绳肌 MTL 变化的理想效果。
手术腘绳肌延长术可以通过 OpenSim 软件中的肌肉骨骼建模来证实。CP 中的手术腘绳肌延长术不会改变腘绳肌延长速度。短而不慢的腘绳肌在腘绳肌延长后会出现持久的 MTL 增加。对于慢的腘绳肌，腘绳肌延长后 MTL 的变化无法维持。无论是短的还是慢的腘绳肌，腘绳肌延长后 MTL 都不会改变。
