Ulnar nerve

1. Ulnar nerve Dr s. bhat

3. Learning objectives • To know the origin, course and distribution of ulnar nerve. • To learn about common applied anatomy of ulnar nerve.

4. Ulnar nerve • Branch from medial cord of brachial plexus • Conveys fibers from C8 & T1 • Receives contribution from C7 through the median nerve for flexor corpi ulnaris

5. Brachial Plexus

6. Course and relations: In the axilla : • Runs along the medial side of third part of the axillary artery in the interval between axillary artery and vein

8. In the arm: • Accompanies the medial side of brachial artery in the proximal half of the arm • Pierces the medial inter-muscular septa in the middle of the arm • Descends superficial to the medial head of the triceps

11. Appears in the interval between medial epicondyle & olecranon process • Lodges in a groove on the dorsal surface of the medial epicondyle, here we can palpate the nerve

12. In the forearm: • Enters the forearm between two heads of flexor carpi ulnaris • Descends along the medial side of the forearm, lying on the flexor digitorum profundus • Proximally nerve is covered by flexor corpi ulnaris

13. distally lies lateral to the flexor carpi ulnaris muscle and is covered only by skin & fascia • Upper third of forearm, the nerve is distinct from ulnar artery, but distally lies close to the medial side of the artery

14. In the hand: • Enters in to the hand by passing deep to the superficial part of flexor retinaculum (in Guyon’s canal) • Deep to the palmaris brevis divide into superficial and deep terminal branches

17. Branches: • No branches in axilla and arm Branches in forearm Motor branches to the:- • flexor carpi ulnaris • medial half of the flexor digitorum profundus (to the tendons of the little & ring fingers)

18. Cutaneous branches:- Dorsal branch: arises 5 cm proximal to the wrist -Supplies skin of the dorsal aspect of medial one and a half of the fingers, excluding terminal phalanges of ring & little fingers Palmar branch: supplies skin of the medial side of the palm

21. In hand: Superficial branch: • Supplies palmaris brevis and medial palmar skin • Divides into two palmar branches, which can be palpated against the hook of the hamate • Proper digital nerve supplies the medial side of the little finger • Common digital nerve divides into two proper digital nerves to supply adjacent sides of the little and ring finger

24. Deep terminal branch: • Accompanies the deep branch of the ulnar artery • Passes between abductor digiti minimi and flexor digiti minimi • Pierces the opponens digiti minimi and turns laterally lodging in a groove below the hook of the hamate • Supplies to the: hypothenar muscles, 3rd and 4th lumbricals, palmar & dorsal interossei & adductor pollicis .

26. Articular branchesto the:- -elbow -intercarpal -carpometacarpal joints Vascular branches to the:- -ulnar -palmar arteries

28. Applied anatomy • Common sites of compression of ulnar nerve • at the elbow • in the cubital tunnel • at the wrist joint • in the hand • The effects of injury depends on the site of lesion

29. Effects of ulnar nerve injury at the elbow • Damaged by • Fracture of medical epicondyle of humerus

30. Cubital tunnel syndrome: • Due to the compression of nerve behind the medial epicondyle • Clinical manifestations:- -on attempting to flex the wrist, the hand is abducted due to the unopposed action of the flexor carpi radialis -medial four fingers cannot be adducted and abducted due to the paralysis of palmar & dorsal interossei -Claw hand is a condition seen in ulnar nerve injury in which medial two fingers are extended at MP joints and flexed at IP joints

31. -Thumb cannot be adducted due to paralysis of adductor pollicis -wasting of hypothenar muscles -loss of sensation of the medial one and a half digits and medial side of the hand

32. Ulnar tunnel syndrome:- -it is an entrapment neuropathy of the ulnar nerve as it passes through the Guyon’s canal symptoms: -pain in the hand or forearm -sensory changes in the palmar aspects of the little and ring fingers -weakness or wasting of the intrinsic muscles of the hand -clawing posture of the hand in extreme cases

33. Ulnar nerve division at the wrist:- Symptoms: -paralysis of all intrinsic muscles of the hand except 1st & 2nd lumbricals -loss of flexion at MP joints and extension at IP joints -unopposed actions of extensors and flexors causes the hand to assume a clawed appearance -sensory loss over the medial one and a half fingers

35. Handlebar neuropathy Cause:- -occurs in people who ride long distances on bicycles -hand grip put pressure on the hooks of their hamates, which compresses the ulnar nerves Symptoms:- -sensory loss on the medial side of the hand -weakness of the intrinsic hand muscles

36. Tests for ulnar nerve lesion:- 1.Patient will not be able to hold a sheet of paper between index and middle fingers 2.Wartenberg’s sign: - patient will not be able to adduct and abduct the four digits, while placing the flat hand on a table

47. Questions • Origin, course, distribution and applied anatomy of ulnar nerve. • Ulnar nerve in hand.

48. Thank you