A morphometric study of variations in the innervation of pronator teres with its clinical implications

Background:The median nerve innervates the forearm and the hand muscles. Variations in its number of branches to pronator teres are frequently seen. The knowledge of its innervation to pronator teres is of utmost importance in understanding the several presentation of pronator teres syndrome, in investigating the median nerve lesions, to design satisfactory treatment, and to avoid iatrogenic injuries during operations. Hence, the aim of this study was to study the innervation of pronator teres muscle and its variations. Materials and Methods:The study was carried out on 24 cadaveric upper limbs. Dissection of the cubital fossa was done and branches of the median nerve to the pronator teres were identified and measured. The elbow articular line (interepicondylar line) was used as a reference point to measure the distance of various branches. Results:We found there were 1, 2, 3 and 4 branches in 5 (20.8%), 12 (50%), 5 (20.8%) and 2 (8.3%) specimens out of 24 upper limbs. In one specimen, we also found that musculocutaneous nerve was supplying the pronator teres muscle and that was arising 10.9 cm above the intercondylar line. Conclusion: This study will increase the knowledge of the anatomical distribution of nerves to pronator teres and therefore help in the treatment of pronator teres syndrome and in various surgical procedures.