Variations of Median Nerve in Carpal Tunnel and its Distribution in Hand

Aim of the study was to study the variations in the branching pattern of median nerve in the carpal tunnel and hand, which would form useful data for hand surgeons doing open/endoscopic carpal tunnel release. Median nerve and its branches were explored by dissection in fifty hands of twenty-five formalin fixed adult human cadavers over a period of three years. We found variations in 35 out of 50 hands. Based upon Lanz classification, frequency of variations in present series was variation in the course of thenar branch (58%), accessory branches at the distal portion of the carpal tunnel (34%), high divisions of the median nerve (8%) and accessory branches proximal to the carpal tunnel (nil). Rare variations including transligamentous median nerve and multiple thenar branches were also observed. Medial take off of thenar branch as observed in this series has special clinical significance in carpal tunnel release. Knowledge of the variable anatomy of median nerve would help to avoid incomplete decompression at operations for nerve entrapment and injury to thenar branch.