HRUS Examinations Of The Entrapment Sites Of The Ulnar Nerve At The Elbow

Objective:To provide individual figures and morphological bases for clinical diagnosis and treatment of Cubital Tunnel Syndrome .Methods:Study the bilateral ulnar nerves at the elbow of 36 persons with high-resolution ultrasonography(HRUS).The entrapment sites include: medial intermuscular septum of the arm , The Structhers arched tissue, arched ligment, cubital tunnel and the two heads of the flexor carpi ulnaris muscle. Measure the distance between the site where the ulnar nerve penetrating the medial intermuscular septum and the lower edge of medial epicondyle and the diameter of the ulnar nerve; Measure the distance between the site where the ulnar nerve penetrating Structhers arch tissue and the lower edge of medial epicondyle and the diameter of the ulnar nerve ; measure the square and perimeter of the cubital tunnel and the ulnar nerve in it (the datas were measured in the position of extension and flexion), calculate the ratio between the cross-section square of the ulnar nerve and the cubital tunnel ; measure the length, width and thickness of the arch ligment; measure the distance between the site where the ulnar nerve penetrating the two heads of flexor carpi ulnaris muscle and the olecranon; measure the diameters and the hemodynamic parameters of nourishing vasculars of the ulnar.Results:The distance between the site where the ulnar nerve penetrating the medial intermuscular septum and the lower edge of medial epicondyle is 11.20±1.35 cm and the diameter of the ulnar nerve is 0.26±0.02 cm,the square is 0.025±0.01 cm2 ,the perimeter is 0.65±0.09 cm; the distance between the site where the ulnar nerve penetrating Structhers arch tissue and the lower edge of medial epicondyle is 8.52±1.02 cm and the diameter of the ulnar nerve is 0.28±0.02 cm; the square and perimeter of the cubital tunnel are 0.55±0.06 cm2 , 3.90±0.21cm in the position of flexion, and the diameter of the ulnar nerve is 0.26±0.02 cm; the square and perimeter of the cubital tunnel are 0.63±0.05 cm2 , 4.02±0.11cm in the position of extension ,and the diameter of the ulnar nerve is 0.31±0.02 cm; the length ,width and thickness of the arch ligment are 1.55±0.01cm, 0.14±0.01cm, 0.075±0.01cm; the distance between the site where the ulnar nerve penetrating the two heads of flexor carpi ulnaris muscle and the olecranon is 1.27±0.14cm,and the diameter of the ulnar nerve is 0.30±0.01cm;the diameter of the Superior ulnar collateral artery is 0.12±0.01 and the hemodynamic parameters of the Superior ulnar collateral artery are below: PS=19.37±3.38,ED=3.38±1.43,R=I0.75±0.10,PI=2.30±0.31; the diameter of the inferior ulnar collateral artery is 0.16±0.02,and the hemodynamic parameters of the inferior ulnar collateral artery are below: PS=20.62±3.18,ED=3.52±1.26,PI=3.21±0.62,RI=1.03±0.13;the diameter of the Ulnar recurrent artery is 0.14±0.01,and the hemodynamic parameters of the ulnar recurrent artery are below: PS=20.42±3.22,ED=3.40±1.13,PI=2.86±0.53,RI=0.88±0.16.Conclusions:High-resolution ultrasound can clearly display the structural characters of the entrapment sites and the nourishing vasculars of the ulnar nerve at the elbow ,providing individual figures and morphological bases for surgery.