Texas Scottish Rite Hospital for Children, Dallas, TX 75219, USA.
J Bone Joint Surg Am. 2011 Jan 5;93(1):49-56. doi: 10.2106/JBJS.I.01557.
The oxygen cost of walking by adults with an amputation has been well described, but few studies have focused on this parameter in children who have had an amputation. Children with a transtibial amputation have been reported to maintain walking speed at a 15% higher oxygen cost than able-bodied children. The purpose of this study was to determine if the level of amputation in children has a differential impact on the self-selected speed of walking and the oxygen cost, and how the performance of these children compares with that of a group of able-bodied children.
Seventy-three children who had had an amputation participated in this study. Oxygen consumption was measured with a Cosmed K4b2 oxygen analysis telemetry unit (Rome, Italy) as the participants walked overground for ten minutes at a self-selected speed. One minute of steady-state data were reduced, averaged, and standardized to control values. Children with a unilateral amputation were grouped according to the level of the amputation; there were twenty-nine Syme, thirteen transtibial, fourteen knee disarticulation, five transfemoral, and five hip disarticulation amputations. Seven children had had a bilateral amputation, and they were considered as a separate group. Comparisons were made among the five amputation groups and between all children who had undergone amputation and control subjects. The variables that were analyzed were resting VO(2) rate (mL/kg/min), resting heart rate (beats per minute [bpm]), walking VO(2) rate (mL/kg/min), walking VO(2) cost (mL/kg/m), walking heart rate (bpm), and self-selected walking velocity (m/min).
Unilateral transfemoral and hip disarticulation amputations resulted in significantly reduced walking speed (80% and 72% of normal, respectively) and increased VO(2) cost (151% and 161% of normal, respectively), while the heart rate was significantly increased in the hip disarticulation group (124% of normal). Compared with the controls, the children with a bilateral amputation walked significantly slower (87% of normal), with an elevated heart rate (119% of normal) but a similar energy cost. Children with a Syme amputation, transtibial amputation, or knee disarticulation walked with essentially the same speed and oxygen cost as did normal children in the same age group.
Children with an amputation through the knee or distal to the knee were able to maintain a normal walking speed without significantly increasing their energy cost. Only when the amputation is above the knee do children walk significantly slower and with an increased energy cost.
成人截肢者行走的耗氧量已得到充分描述，但很少有研究关注截肢儿童的这一参数。有研究报道，与健全儿童相比，胫骨截肢儿童以 15%更高的耗氧量维持行走速度。本研究旨在确定儿童截肢的水平是否对其自主选择的行走速度和耗氧量有不同的影响，以及这些儿童的表现与健全儿童的表现相比如何。
73 名截肢儿童参与了这项研究。参与者以自主选择的速度在地面上行走十分钟，用 Cosmed K4b2 氧分析遥测单元（意大利罗马）测量耗氧量。对 1 分钟的稳态数据进行了简化、平均和标准化处理，以控制值。根据截肢水平，单侧截肢儿童分为 29 例 Syme 截肢、13 例胫骨截肢、14 例膝关节离断截肢、5 例股骨截肢和 5 例髋关节离断截肢。7 例儿童进行了双侧截肢，将其视为一个单独的组。对 5 个截肢组之间以及所有截肢儿童与对照组之间进行了比较。分析的变量包括静息 VO2 率（mL/kg/min）、静息心率（bpm）、行走 VO2 率（mL/kg/min）、行走 VO2 消耗（mL/kg/m）、行走心率（bpm）和自主选择的行走速度（m/min）。
单侧股骨截肢和髋关节离断截肢导致行走速度明显下降（分别为正常的 80%和 72%）和耗氧量增加（分别为正常的 151%和 161%），而髋关节离断组的心率明显增加（正常的 124%）。与对照组相比，双侧截肢儿童的行走速度明显较慢（正常的 87%），心率较高（正常的 119%），但能量消耗相似。Syme 截肢、胫骨截肢或膝关节离断的儿童的行走速度和耗氧量与同龄正常儿童基本相同。
膝关节以下或更远部位截肢的儿童能够以正常行走速度行走，而不会显著增加能量消耗。只有当截肢部位高于膝关节时，儿童的行走速度才会显著减慢，能量消耗也会增加。
