D. J. Schuett, US Naval Hospital, Okinawa, Japan M. P. Wyatt, T. Kingsbury, N. Thesing, K. M. Kuhn, Naval Medical Center San Diego, San Diego, CA, USA D. M. Dromsky, Orthopedics Department, Conroe Regional Medical Center, Conroe, TX, USA.
Clin Orthop Relat Res. 2019 Apr;477(4):821-825. doi: 10.1007/s11999.0000000000000212.
Through-knee amputation is a common amputation level after battlefield injuries during the medical evacuation process. However, there are limited data comparing through-knee amputation with transfemoral amputation as a definitive amputation level in terms of gait parameters.
QUESTIONS/PURPOSES: (1) Does through-knee amputation result in improved gait velocity when compared with matched transfemoral amputees? (2) Do through-knee amputees have a faster gait cadence than matched transfemoral amputees? (3) Do through-knee amputees have a different stride length or stride width than matched transfemoral amputees? (4) Does through-knee amputation result in decreased work of ambulation when compared with matched transfemoral amputees?
Between January 2008 and December 2012, six male active-duty military patients who had undergone unilateral through-knee amputations as a result of trauma underwent gait studies at our institution. Of those, four of six underwent gait analysis after being able to walk for at least 3 months without assistive devices, and this group was studied here. Most through-knee amputees who were not included had elective revisions of their amputations from through-knee to a transfemoral amputation before completing 3-month gait data. Each of the amputees studied was matched to a transfemoral amputee based on height, body mass index, and contralateral amputation level resulting in a case-control study of active-duty military male amputee patients. Inclusion required complete gait data collected while walking at a self-selected pace wearing custom prosthetic devices. The through-knee amputees had a median (range) age of 32 years (23-41 years) and the transfemoral amputees had a median age of 24 years (22-27 years). Three-dimensional gait data were collected and analyzed. A power analysis found that to detect a clinically important difference (set at a change in work of ambulation of 1 J/kgm) with a p value of 0.05 and a β set to 0.2, a study population of 56 patients per group would be required; that being said, our results on a much smaller population must be considered exploratory.
With the numbers available, we found no differences in gait velocity when comparing through-knee (1.18 m/sec) and matched transfemoral amputees (1.20 m/sec, difference of medians = 0.02 m/sec; p = 0.964). Likewise, we found no differences in gait cadence when comparing through-knee with transfemoral amputees (104 versus 106 steps/min, respectively, difference of means 2 steps/min, p = 0.971). There was no difference in stride length or stride width when comparing through-knee (70 cm and 18 cm, respectively) with transfemoral amputees (70 cm and 19 cm, respectively; p = 0.948 and p = 0.440). With the numbers available, we did not identify a difference in the work of ambulation for through-knee amputees when compared with matched transfemoral amputees (8.3 versus 7.5 J/kg, respectively; p = 0.396).
Based on our findings, we are unable to demonstrate any functional advantages of knee disarticulation over transfemoral amputation. Although there are theoretical advantages for maintaining an intact femur during the medical evacuation and serial débridement process, we question the utility of knee disarticulation as a definitive amputation level; however, larger numbers of patients are needed to confirm these results.
Level III, therapeutic study.
在医疗后送过程中，经过战场受伤后的常见截肢水平是膝关节离断。然而，在步态参数方面，将膝关节离断与股骨截肢作为确定性截肢水平进行比较的相关数据有限。
问题/目的：（1）与匹配的股骨截肢患者相比，膝关节离断是否会导致步行速度提高？（2）膝关节离断患者的步频是否快于匹配的股骨截肢患者？（3）膝关节离断患者的步幅或步宽是否与匹配的股骨截肢患者不同？（4）与匹配的股骨截肢患者相比，膝关节离断是否会导致步行功减少？
2008 年 1 月至 2012 年 12 月，由于创伤导致单侧膝关节离断的 6 名现役男性军事患者在我院进行了步态研究。其中，6 名患者中有 4 名在至少 3 个月不使用辅助设备行走后进行了步态分析，本研究包括这 4 名患者。大多数未包括的膝关节离断患者在完成 3 个月的步态数据之前，由于 elective 修订了他们的截肢手术，将膝关节离断修订为股骨截肢。每个研究的截肢患者都根据身高、体重指数和对侧截肢水平与股骨截肢患者相匹配，从而对现役男性截肢患者进行了病例对照研究。纳入标准为穿着定制假体设备以自选择的速度行走时收集完整的步态数据。膝关节离断患者的中位（范围）年龄为 32 岁（23-41 岁），股骨截肢患者的中位年龄为 24 岁（22-27 岁）。收集并分析了三维步态数据。一项功率分析发现，为了检测具有临床意义的差异（设定为步行功的变化为 1 J/kgm），p 值为 0.05，β 设置为 0.2，每组需要 56 名患者的研究人群；话虽如此，我们在人数较少的情况下得出的结果必须被认为是探索性的。
根据现有的数据，我们发现膝关节离断（1.18 m/sec）和匹配的股骨截肢患者之间的步行速度没有差异（1.20 m/sec，中位数差异为 0.02 m/sec；p = 0.964）。同样，我们发现膝关节离断与股骨截肢患者的步频没有差异（分别为 104 步/分钟和 106 步/分钟，平均差异为 2 步/分钟，p = 0.971）。膝关节离断与股骨截肢患者的步幅（分别为 70cm 和 18cm）和步宽（分别为 70cm 和 19cm）没有差异（p = 0.948 和 p = 0.440）。根据现有的数据，我们没有发现膝关节离断患者与匹配的股骨截肢患者相比步行功有差异（分别为 8.3 与 7.5 J/kg，p = 0.396）。
根据我们的发现，我们无法证明膝关节离断在功能上优于股骨截肢。尽管在医疗后送和连续清创过程中保持股骨完整有理论上的优势，但我们质疑膝关节离断作为确定性截肢水平的实用性；然而，需要更多的患者数量来证实这些结果。
三级，治疗性研究。
