Bagatur A Erdem, Yalcinkaya Merter, Atca Ali Onder
Department of Orthopaedic Surgery and Traumatology, Medicana International Istanbul Hospital, Istanbul, Turkey.
Orthopedics. 2013 Apr;36(4):e451-6. doi: 10.3928/01477447-20130327-21.
Carpal tunnel syndrome can be secondary in some patients, and vascular anomalies (usually a persistent median artery), median nerve variations, or both are among the etiologic factors. High division of the median nerve proximal to the carpal tunnel (known as a bifid median nerve) is a median nerve anomaly that has an incidence rate of 2.8%. This rare entity is often associated with various abnormalities that are clinically relevant, such as vascular malformations (persistent median artery), aberrant muscles, and carpal tunnel syndrome. The bifid median nerve is one cause of carpal tunnel syndrome because of its relatively higher cross-sectional area compared with a nonbifid median nerve. Obtaining magnetic resonance imaging and ultrasounds of bifid median nerves has helped surgeons avoid potential surgical hazards.This article describes 3 men with 4 bifid median nerves associated with a persistent median artery. Mean patient age was 38 years (range, 37-40 years). Mean follow-up was 7 years (range, 3-11 years). Patients were diagnosed with carpal tunnel syndrome and underwent open carpal tunnel release. To reveal a morphological etiology in patients in whom it the possibility of having idiopathic carpal tunnel syndrome is unlikely, preoperative imaging studies should be obtained. Bifid median nerves associated with a persistent median artery in the carpal tunnel are important to understand for their clinical and surgical significance. A secondary nature should be suspected in patients with unilateral symptoms, especially those with a history of symptoms and when the symptomatic hand shows severe neurophysiologic impairment but the contralateral hand is neurophysiologically intact. Inadvertent injury to the median nerve during carpal tunnel surgery can be minimized if the variations of the median nerve are recognized.
在一些患者中，腕管综合征可能是继发性的，血管异常（通常是持续存在的正中动脉）、正中神经变异或两者皆是病因。正中神经在腕管近端高位分支（称为双叉正中神经）是一种正中神经异常，发生率为2.8%。这种罕见情况常与各种具有临床相关性的异常有关，如血管畸形（持续存在的正中动脉）、异常肌肉和腕管综合征。双叉正中神经是腕管综合征的一个病因，因为与非双叉正中神经相比，其横截面积相对较大。获取双叉正中神经的磁共振成像和超声有助于外科医生避免潜在的手术风险。本文描述了3名男性患者，他们共有4条与持续存在的正中动脉相关的双叉正中神经。患者平均年龄为38岁（范围37 - 40岁）。平均随访时间为7年（范围3 - 11年）。患者被诊断为腕管综合征并接受了开放性腕管松解术。对于不太可能患有特发性腕管综合征的患者，为揭示其形态学病因，应进行术前影像学检查。了解腕管内与持续存在的正中动脉相关的双叉正中神经的临床和手术意义很重要。对于有单侧症状的患者，尤其是有症状病史且患侧手出现严重神经生理学损害而对侧手神经生理学正常的患者，应怀疑为继发性病因。如果能识别正中神经的变异，在腕管手术中可将正中神经的意外损伤降至最低。
