This document summarizes injuries to the ulnar nerve at different locations. It describes the motor and sensory functions of the ulnar nerve and the effects of injuries to the ulnar nerve at the elbow or wrist. An injury to the ulnar nerve at the elbow can cause paralysis of hand muscles and clawing of the ring and little fingers. Sensory loss from an elbow injury affects the medial hand and 1.5 fingers. A wrist injury causes similar but less severe effects. Treatment options described include nerve stimulation, splinting, exploration and repair of any defects in the nerve.

1. Injury of ulnar nerve
HAMAD EMAD HAMAD DHUHAYR
10110067

2. Ulnar Nerve
Roots: C8 and T1.
Motor Functions: Innervates the muscles of the hand (apart from the thenar
muscles and two lateral lumbricals), flexor carpi ulnaris and medial half of flexor
digitorum profundus.
Sensory Functions: Innervates the anterior and posterior surfaces of the medial
one and half fingers, and associated palm area.

3. Injury to the Ulnar Nerve
(motor at elbow)
Flexor carpi ulnaris & medial half of flexor digitorum profundus are paralyzed
In a tightly clenched fist the tightening of the tendon of profundus is absent
Profundus tendon to the ring & little fingers will be functionless
Terminal phalanges of these fingers fail to flex properly

4. Injury to the Ulnar Nerve
(motor at elbow)
Flexion of wrist joint will result in abduction due to paralysis of flexor carpi
ulnaris.
Small muscles of hand will be paralyzed except the muscles of thenar eminence
and first 2 lumbricals.
Adductor pollicis longus is paralyzed so the adduction of thumb is not possible

5. Injury to the Ulnar Nerve
(motor at elbow)
Metacarpophalangeal joints become hyperextended due to the paralysis of
lumbrical and interosseous muscles
Interphalangeal joints are flexed due to the same reason as mentioned above
Dorsum of hand will show hollowing due to the wasting of dorsal interosseous
muscles

6. Injury to the Ulnar Nerve
(sensory at elbow)
Loss of skin sensation of anterior & posterior surfaces of the medial 3rd of the
hand and medial 1 & ½ fingers
The skin areas involved in sensory loss are warmer and drier than normal
Arteriolar dilatation and absence of sweating resulting from loss of sympathetic
control

7. Injury to the Ulnar Nerve
(motor at wrist)
Small muscles of the hand will be paralyzed
Claw hand is more obvious as flexor digitorum profundus is not
paralyzed
Marked flexion of the terminal phalanges occur

9. Injury to the Ulnar Nerve
(sensory at wrist)
The sensory loss is usually confined to the palmar surface of medial 3rd of the hand and the
medial 1 & ½ finger
Trophic changes are same as that injuries of ulnar nerve at elbow
Unlike median nerve injuries, lesions of ulnar nerve leave a relatively efficient hand
Pincer like action is good

11. a- Closed injury:-
- Expectant TTT for 6 m.
• Electric stimulation of m.
• Physiotherapy.
• Splint in position of best function.
!f no response:- -
• Exploration of nerve.
• Remove any neuroma, glioma or intervening T.
• Trim & anastomosis the ends.
lf wide gap:-
- N. graft or n. transposition (infront of med. Epicondyle)
b- Open injury:-
Only debridement (no 1ry repair)
Repair lf not infected) delayed '1ry repair (after 3 w.)
lf infected ) 2'Y reoair (after 6 w.