Haberfehlner Helga, Jaspers Richard T, Rutz Erich, Harlaar Jaap, van der Sluijs Johannes A, Witbreuk Melinda M, van Hutten Kim, Romkes Jacqueline, Freslier Marie, Brunner Reinald, Becher Jules G, Maas Huub, Buizer Annemieke I
Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Amsterdam Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
Pediatric Orthopaedic Department, University Children's Hospital Basle, Basle, Switzerland.
PLoS One. 2018 Feb 6;13(2):e0192573. doi: 10.1371/journal.pone.0192573. eCollection 2018.
To improve gait in children with spastic paresis due to cerebral palsy or hereditary spastic paresis, the semitendinosus muscle is frequently lengthened amongst other medial hamstring muscles by orthopaedic surgery. Side effects on gait due to weakening of the hamstring muscles and overcorrections have been reported. How these side effects relate to semitendinosus morphology is unknown. This study assessed the effects of bilateral medial hamstring lengthening as part of single-event multilevel surgery (SEMLS) on (1) knee joint mechanics (2) semitendinosus muscle morphology and (3) gait kinematics. All variables were assessed for the right side only. Six children with spastic paresis selected for surgery to counteract limited knee range of motion were measured before and about a year after surgery. After surgery, in most subjects popliteal angle decreased and knee moment-angle curves were shifted towards a more extended knee joint, semitendinosus muscle belly length was approximately 30% decreased, while at all assessed knee angles tendon length was increased by about 80%. In the majority of children muscle volume of the semitendinosus muscle decreased substantially suggesting a reduction of physiological cross-sectional area. Gait kinematics showed more knee extension during stance (mean change ± standard deviation: 34±13°), but also increased pelvic anterior tilt (mean change ± standard deviation: 23±5°). In most subjects, surgical lengthening of semitendinosus tendon contributed to more extended knee joint angle during static measurements as well as during gait, whereas extensibility of semitendinosus muscle belly was decreased. Post-surgical treatment to maintain muscle belly length and physiological cross-sectional area may improve treatment outcome of medial hamstring lengthening.
为改善因脑瘫或遗传性痉挛性轻瘫导致痉挛性轻瘫儿童的步态，在骨科手术中，半腱肌常与其他腘绳肌内侧肌肉一同被延长。已有报告指出腘绳肌减弱和过度矫正对步态产生的副作用。这些副作用与半腱肌形态之间的关系尚不清楚。本研究评估了作为单事件多节段手术（SEMLS）一部分的双侧腘绳肌内侧延长对（1）膝关节力学、（2）半腱肌形态和（3）步态运动学的影响。所有变量仅对右侧进行评估。对六名因膝关节活动范围受限而被选进行手术的痉挛性轻瘫儿童在手术前及术后约一年进行了测量。术后，大多数受试者的腘窝角减小，膝关节力矩-角度曲线向膝关节更伸展的方向移动，半腱肌肌腹长度大约减少了30%，而在所有评估的膝关节角度下，肌腱长度增加了约80%。在大多数儿童中，半腱肌的肌肉体积大幅减少，表明生理横截面积减小。步态运动学显示站立期膝关节伸展增加（平均变化±标准差：34±13°），但骨盆前倾也增加（平均变化±标准差：23±5°）。在大多数受试者中，半腱肌肌腱的手术延长在静态测量以及步态过程中都有助于膝关节角度更伸展，而半腱肌肌腹的伸展性降低。术后维持肌腹长度和生理横截面积的治疗可能会改善腘绳肌内侧延长的治疗效果。
