INNERVATIONS OF PRONATOR TERES MUSCLE BY MEDIAN NERVE: A CADAVERIC STUDY

Abstract

Background: Median nerve innervates muscles of forearm & hand. Anatomical variations are found in its innervations to muscles, one of them is pronator teres. The knowledge of variation of median nerve in relation with Pronator teres muscle is very important for understanding of pronator teres syndrome, its accurate diagnosis and proper treatment, so as to avoid the injury to either nerve or Pronator teres muscle. Materials and methods: The study was carried out at the Department of the Anatomy, Bharati Vidyapeeth (deemed to be university) Medical College and Hospital, Sangli and GMC Miraj.100 formalin fixed specimens of upper limb from 50 adult cadavers (irrespective of sex and age 25-70 years), were dissected. After careful dissection, relation of median nerve with pronator teres muscle, number of branches innervating muscle, distance between intercondylar line and median nerve piercing Pronator Teres were noted and recorded. Data was analyzed by microsoft excel analysis. Observation and Results: In present study, in all the specimens (100%) the median nerve entered the forearm by passing between the two heads of Pronator teres muscle. Median nerve innervated Pronator teres by 2 branches in 75% specimens. Innervation by 3 branches was observed in 15% specimens and by only 1 branch in 15% specimens. One new parameter was introduced i.e. the distance from intercondylar line to a point where median nerve (trunk) pierced the pronator teres muscle.It was measured with the help of vernier caliper. The minimum distance observed was 23mm and maximum distance was 73mm. Conclusion:The study will add to the knowledge of variations in innervations of Pronator teres muscles by median nerve and can be of use in treatment of MN entrapment syndrome and surgical procedures.