BACKGROUND The purpose of this study was to assess the results of elbow flexion strength fatigue, rather than the maximal power of strength, after brachial plexus re-innervation with phrenic and spinal accessory nerves. We designed a simple but specific test to study whether statistical differences were observed among those two donor nerves. METHOD We retrospectively reviewed patients with severe brachial plexus palsy for which either phrenic nerve (PN) or spinal accessory nerve (SAN) to musculocutaneous nerve (MCN) transfer was performed. A dynamometer was used to determine the maximal contraction strength. One and two kilograms circular weights were utilized to measure isometrically the duration of submaximal and near-maximal contraction time. Statistical analysis was performed between the two groups. RESULTS Twenty-eight patients were included: 21 with a PN transfer while 7 with a SAN transfer for elbow flexion. The mean time from trauma to surgery was 7.1 months for spinal accessory nerve versus 5.2 for phrenic nerve, and the mean follow-up was 57.7 and 38.6 months, respectively. Statistical analysis showed a quicker fatigue for the PN, such that patients with the SAN transfer could hold weights of 1 kg and 2 kg for a mean of 91.0 and 61.6 s, respectively, while patients with transfer of the phrenic nerve could hold 1 kg and 2 kg weights for just a mean of 41.7 and 19.6 s, respectively. Both differences were statistically significant (at p = 0.006 and 0.011, respectively). Upon correlation analysis, endurances at 1 kg and 2 kg were strongly correlated, with r = 0.85 (p < 0.001). CONCLUSIONS Our results suggest that phrenic to musculocutaneous nerve transfer showed an increased muscular fatigue when compared with spinal accessory nerve to musculocutaneous transfer. Further studies designed to analyze this relation should be performed to increase our knowledge about strength endurance/fatigue and muscle re-innervation.

中文翻译：

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在臂丛神经损伤中使用不同的供体时，强度疲劳的差异。

背景技术本研究的目的是评估用bra神经和脊柱副神经支配臂丛神经后肘屈肌力量疲劳的结果，而不是最大力量。我们设计了一个简单但具体的测试来研究在这两个供体神经之间是否观察到统计学差异。方法我们回顾性分析了重度臂丛神经麻痹的患者，这些患者均进行了PN神经（PN）或脊柱副神经（SAN）向肌皮神经（MCN）的转移。用测力计确定最大收缩强度。用一公斤和两公斤的圆形砝码等距地测量次最大和接近最大收缩时间的持续时间。两组之间进行统计分析。结果共纳入28例患者：21例行PN转移，而7例行SAN转移以屈肘。脊柱副神经从创伤到手术的平均时间为7.1个月，phr神经为5.2个月，平均随访时间分别为57.7和38.6个月。统计分析显示，PN较快疲劳，SAN转移患者的体重分别为1 kg和2 kg，平均分别为91.0和61.6 s，而with神经转移患者的体重为1 kg和2 kg。 2 kg的重量分别平均为41.7和19.6 s。两种差异均具有统计学意义（分别为p = 0.006和0.011）。经过相关性分析，在1 kg和2 kg的耐力高度相关，r = 0.85（p <0.001）。结论我们的结果表明，与脊柱副神经向肌肉皮肤的转移相比，to向肌肉皮肤的神经转移显示出肌肉疲劳的增加。应该进行旨在分析这种关系的进一步研究，以增加我们对力量耐力/疲劳和肌肉再支配的认识。