- Discussion:
- ulnar nerve blocks are used for frxs of little finger ray & in along w/ median and radial sensory blocks for ring finger ray fractures;
- Anatomy:
- ulnar nerve has two sensory branches that provide sensory innervation to ulnar side of the hand;
- palmar branch
- found radial to FCU tendon at proximal crease;
- dorsal branch
- divides from palmar branch approx 4-5 cm proximal from wrist;
- courses under FCU tendon to dorsal ulnar side of the hand;
- ulnar nerve block at at elbow where nerve courses 0.5 cm below the skin between the medial epicondyle & olecranon;
- ulnar nerve is palpated between medial epicondyle & olecranon;
- inject 2-3 ml of anesthetic on either side of nerve but not directly into it;
- paresthesias indicate proximity, and therefore, the needle has to be moved slightly away from the nerve before injection;
- ulnar block nerve at wrist:
- ulnar nerve lies just under FCU tendon proximal to the wrist crease;
- aspiration is necessary prior to injection, as ulnar artery runs adjacent to the nerve;
- note that the ulnar artery lies superficial (volar) and radial to the ulnar nerve;
- to block dorsal sensory branch of ulnar nerve, the needle is passed subQ & directed dorsally toward the base of the fifth metacarpal