Liu Yang, Rui Jing, Gao Kaiming, Lao Jie
Department of Hand Surgery, Huashan Hospital, Fudan University, Shanghai, China.
Key Laboratory of Hand Reconstruction, Ministry of Health, Shanghai, China.
Ann Transl Med. 2020 Dec;8(23):1563. doi: 10.21037/atm-20-1466.
The first dorsal interosseous muscle (FDI) is usually innervated by the deep branch of the ulnar nerve. However, as was first noted by Sunderland in 1946, some individuals have variable innervation of the FDI. This study investigated the incidence of variable innervation of the FDI by using electrophysiological examination and further evaluated the relevance of this variation in patients with cubital tunnel syndrome (CuTS).
This study included 211 patients who underwent peripheral nerve surgery in Huashan hospital, Fudan University, between October, 2012 and February, 2014. The patients were divided into three groups: the carpal tunnel syndrome (CTS) group, the CuTS group and the control group. During surgery, electromyography was used to determine FDI variation, and a hand function instrument was employed to estimate the pinch strength between the thumb and index finger in both hands of the CuTS patients.
The electromyogram test showed that 22 of the patients enrolled had variable innervation of the FDI. Compared with the CTS group and the control group, the incidence of variable innervation of the FDI was much higher in the CuTS group (P<0.05). Patients under the age of 60 years old in the CuTS group were more likely to have the variation (P=0.043). A higher pinch strength ratio was significantly associated with variable innervation of the FDI in the CuTS patients (P=0.030).
Using electromyography, our study demonstrated that the variable innervation of the FDI could be innervated by the median nerve. In the CuTS patients, the higher incidence of FDI variation was possibly related to age. This variation might lead to a better prognosis for CuTS patients.
第一背侧骨间肌（FDI）通常由尺神经深支支配。然而，正如桑德兰于1946年首次指出的那样，一些个体的FDI存在变异支配情况。本研究通过电生理检查调查FDI变异支配的发生率，并进一步评估这种变异在肘管综合征（CuTS）患者中的相关性。
本研究纳入了2012年10月至2014年2月期间在复旦大学附属华山医院接受周围神经手术的211例患者。患者分为三组：腕管综合征（CTS）组、CuTS组和对照组。手术过程中，采用肌电图确定FDI变异情况，并使用手部功能仪器评估CuTS患者双手拇指与示指之间的捏力。
肌电图检查显示，纳入的患者中有22例存在FDI变异支配。与CTS组和对照组相比，CuTS组中FDI变异支配的发生率要高得多（P<0.05）。CuTS组中60岁以下的患者更有可能出现这种变异（P=0.043）。在CuTS患者中，较高的捏力比值与FDI变异支配显著相关（P=0.030）。
通过肌电图检查，我们的研究表明FDI的变异支配可能由正中神经支配。在CuTS患者中，FDI变异的较高发生率可能与年龄有关。这种变异可能会使CuTS患者预后更好。
