Anatomy And Clinical Study Of The Entrapment Of Median Nerve At Elbow

Objective:To provide anatomic basis for the entrapment of median nerve at elbow and for repair of important branches of the median nerve in the upper arm.Methods:10 upper limbs of cadavers were used. Microanatomical dissection of the median nerve was done to observe the compression factor of median nerve at elbow and the distribution of fascicular groups of the median nerve in the upper arm. And Anatomical analysis of 14 patients with the entrapment of median nerve at elbow were treated in our department.Results:In the relationships between bicipital aponeurosis (BA) and median nerve(MN),there are complete-covering type(2,in20%),partial-covering(1,in10%) and non-covering(7,in70%). The thickened fascia in the superficial layer of ulnar head was seen in 9 limbs (90%). The obvious intramuscular tendinous bundles in the humeral heads were observed in 2(20%). The reverse fascia were seen in 6 (60%).The structures of origin border between two heads of flexor digitorum superficialis(FDS) have three types, that is intramuscular tendinous bundle (1,in10%),fibrous arch (1,in10%), conjoined tendinous arch (8,in80%);In the upper arm, branches of the median nerve constantly formed three fascicular groups. The anterior part of nerve trunk hosted branches to the pronator teres (PT) and the flexor carpi radialis (FCR). The posterior part of nerve trunk contained the anterior interosseous nerve (AIN) and branches to the palmaris longus muscle (PL).the main trunk of the median nerve at the proximal forearm were grouped to form the middle part. Clinical data showed:14 patients presented with compression parts involving the lacertus fibrous (n=2), reverse fascia (n=4), The thickened fascia in the superficial layer of ulnar head (n=1), between the ulnar head and the humeral heads (n=2),and The structures of origin border between two heads of flexor digitorum superficialis (n=5).Some patients were followed up. Good to excellent recovery of motor function was achieved in 6 follow-up of patients. The average follow-up time of 2 years and 4 months.Conclusions:The shape of the median nerve, peripheral lacertus, thickened and tensive fascia at elbow are the anatomic basis of median nerve entrapment; By understanding the characteristics of three fascicular groups local orientation of the median nerve in the upper arm, there are important clinical significance for selectively repaired and partial transferred the median nerve.