Department of Anatomy, All India Institute of Medical Sciences, Patna, India.
Department of Anatomy, All India Institute of Medical Sciences, Bathinda, India.
Clin Anat. 2022 Oct;35(7):946-952. doi: 10.1002/ca.23900. Epub 2022 May 9.
As the median nerve enters the carpal tunnel, it is a single nerve that soon bifurcates into lateral and medial branches into the hand. If the bifurcation is proximal to the carpel tunnel, a bifid median nerve (BMN) results. Carpal tunnel syndrome is often associated with a BMN with or without a persistent median artery. Individual keywords and MeSH phrases were searched in the Google Scholar, SCOPUS, and PubMed databases. Full texts were then collected and assessed for suitability. The prevalence of BMN at the wrist joint in normal and carpal tunnel syndrome wrists (precanal part) and the mean difference between groups were recorded. Only human data were used to test the findings. The pooled odds ratio (with minimal heterogeneity) was 1.50 [1.17-1.93, 95% CI]. The BMN cross-sectional area (CSA) was significantly greater than that of a solitary median nerve in normal wrists. The mean difference in CSA between the two was 1.50 mm [0.56-2.45 mm , 95% CI] without heterogeneity (i = 0). Sex and laterality distributions scarcely differed between the two types of wrists. Owing to the insufficiency of data, the relationships with mean height and weight were not examined. There was a 50% greater incidence of bifid median nerves in carpal tunnel syndrome patients than in normal subjects. A bifid median nerve increases the mean CSA at the wrist joint by 1.5 mm . These findings indicate that the bifid median nerve is an anatomical risk factor for carpal tunnel syndrome.
正中神经进入腕管时，是一条单一的神经，很快就在手部分为外侧和内侧分支。如果分支位于腕管近端，则会形成分叉正中神经（BMN）。腕管综合征常与 BMN 伴发或不伴固有正中动脉。在 Google Scholar、SCOPUS 和 PubMed 数据库中单独搜索关键词和 MeSH 短语。然后收集全文并评估其适用性。记录正常和腕管综合征手腕（管前部分）正中神经分叉处的 BMN 发生率和组间平均差异。仅使用人类数据来检验研究结果。汇总的优势比（最小异质性）为 1.50 [1.17-1.93，95%置信区间]。正常手腕中 BMN 的横截面积（CSA）明显大于单一正中神经。两者之间 CSA 的平均差异为 1.50mm [0.56-2.45mm，95%置信区间]，无异质性（i = 0）。两种类型手腕的性别和侧别分布差异不大。由于数据不足，未检查与平均身高和体重的关系。腕管综合征患者中 BMN 的分叉发生率比正常受试者高 50%。BMN 的分叉会使腕关节处 CSA 平均增加 1.5mm。这些发现表明，分叉正中神经是腕管综合征的解剖学危险因素。
