OBJECTIVES To implement a functional electrical stimulation (FES) hand neuroprosthesis called the Freehand System in a growing child with spinal cord injury (SCI) using extra lead wire to accommodate limb growth, and to evaluate the performance of the Freehand System during the subject's maturation. SETTING Pediatric orthopedic hospital specializing in SCI rehabilitation. SUBJECT Ten-year-old female patient with a C5 level SCI. METHOD The Freehand System was implanted. Eight electrodes were implanted to targeted forearm and hand muscles to provide grasp and release function. The lead wire associated with each electrode was pathed subcutaneously up the arm with 4 cm of extra lead distributed throughout the path to accommodate expected limb growth. All leads were attached to a stimulator placed in the upper chest. Measures of lead unwinding, limb growth, stimulated muscle strength, and hand function were made at 6 and 16 months after implant. RESULTS By 16 months post implant, the upper limb growth plates were closed and humeral and radial bone growth combined was 2.7 cm from the time of surgery. For all eight leads, lead unwinding in the upper arm was approximately 1.2 cm and was comparable to humeral bone growth (1.4 cm). Lead unwinding in the lower arm was also measurable for the two electrodes in hand muscles. Six of eight electrodes maintained grade 3 or better stimulated muscle strength throughout the growth period according to a manual muscle test. Of the two other electrodes, one appeared to have lost function due to depletion of excess lead. However, hand function with FES was comparable at 6 and 16 months post implant suggesting that growth did not negatively impact performance with the FES system. Hand function with FES was improved over voluntary hand function as well. Using the Freehand System, a pinch force of approximately 15 N was achieved compared to 1.3 N of voluntary tenodesis pinch force. Scores on the Functional Independence Measure (FIM) increased by 9 points when FES was used as compared to voluntary function. Improvements occurred primarily in eating and grooming. Independence in writing was achieved only with FES. CONCLUSIONS For this child, hand function with the Freehand System was sustained over the growth period and was a significant functional improvement over voluntary hand function. By using excess lead wire, the Freehand System was successfully implemented before skeletal maturity, affording the child improved hand function earlier than would be otherwise indicated.

中文翻译：

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成长中的C5脊髓损伤儿童的植入式上肢神经假体。

目的在成长中的脊髓损伤（SCI）儿童中使用额外的导线来适应肢体生长，以实现称为Freehand系统的功能性电刺激（FES）手神经假体，并评估受试者成熟过程中Freehand系统的性能。设置专门从事SCI康复的儿科骨科医院。受试者一名C5级SCI的十岁女性患者。方法徒手系统被植入。八个电极被植入目标前臂和手部肌肉，以提供抓握和释放功能。将与每个电极关联的导线沿皮下路径穿过手臂，并在整个路径中分布4厘米的额外导线，以适应预期的肢体生长。所有导线都连接到放在上胸部的刺激器上。铅退绕的措施，植入后6个月和16个月，肢体生长，刺激的肌肉力量和手功能得以改善。结果植入后16个月，上肢生长板已关闭，距肱骨和radial骨的骨合并生长时间为手术时间2.7 cm。对于所有八根导线，上臂中的导线退绕约为1.2厘米，与肱骨长（1.4厘米）相当。对于下肢的两个电极，也可以测量下臂中的铅卷。根据人工肌肉测试，八个电极中的六个在整个生长期中保持3级或更高的刺激肌肉强度。在另外两个电极中，一个似乎由于多余的铅耗尽而失去了功能。然而，FES的手功能在植入后的6个月和16个月时具有可比性，这表明FES系统的生长不会对性能产生负面影响。FES的手功能也优于自愿手功能。使用Freehand系统时，可实现约15 N的压紧力，而自愿性腱固定压紧力为1.3N。与自愿功能相比，使用FES时功能独立性评估（FIM）得分提高了9分。改善主要发生在饮食和美容方面。只有FES才能实现书面独立。结论对于这个孩子，徒手系统的手部功能在整个成长过程中得以维持，并且比自愿手部功能有了重大改善。通过使用多余的导线，