Nerve Injuries upper limb

Question 1

Injury to radial nerve spiral groove humerus cause, what’s affected

Answer 1

Mid-shaft humeral fracture. Extension elbow normal nerve supply to triceps given before groove. Anconeus paralysed (minor role). Wrist and fingers flexed- paralysis of brachioradialis and extensor muscles of wrist and fingers ‘wrist drop’, pronated forearm. Posterior cutaneous nerve above spiral groove. Paraesthesia distribution surperif oak branch (dorsal hand on radial half and 3.5 radial fingers)

Question 2

High median nerve injury in arm how, effects

Answer 2

Above elbow- post supracondylar fracture of humerus paralyse muscles (pronator teres, flexor carpi radialis, palmaris longus, flexor digitorum superficialis). Forearm supinated, opposition and palmar abduction thumb absent. All DIPj paralysed. Make a fist- index and middle finger remain extended ‘hand of benediction’
LR thumb loss opponents pollicis. Wasting thenar eminence/ ape hand deformity. Sensory loss radial side of hand (thumb, 2nd, 3rd and half of ring palmar side, fingertips of 1st, 2nd, 3rd)

Question 3

Injury median nerve at wrist how, effects

Answer 3

Low median nerve injury- penetrating/ compression injury

Muscles paralysed = LOAF
Lumbricals index and middle, opponens pollicis, abductor pollicis brevis, flexor pollicis brevis

Ape hand deformity, thenar eminence flattened, thumb adducted and external,y rotated

Question 4

Ulnar nerve injury at wrist cause, effects

Answer 4

Low ulnar claw- laceration/ guyon’s canal impair: hypothenar eminence, adductor pollicis, flexor pollicis brevis, interossei, lumbricals ring and little, palmaris brevis, palmar 1.5 fingers ulnar up to DIPJ.

Long standing-> claw hand, ring and little extended MCPJ and flexed at IP joints

Guttering- wasting interossei- between metacarpals, atrophy adductor pollicis. Atrophy hypothenar eminence. Sensation lost palmar ulnar 1.5 and distal phalanges on dorsum.

Question 5

Injury ulnar nerve at elbow how, effects, paradox

Answer 5

Medial epicondyle fracture/ compression cubital tunnel

Paralysis flexor carpi ulnaris, ulnar half flexor digitorum profundus and loss sensation dorsal and palmar cutaneous branches- sensation lost dorsum and palmar ulnar 1.5 and onto hand.

Less pronounced clawing - no flexion of DIPj ring and little. Hyperextension MCPj and flexion PIPjs only.

‘Ulnar paradox’ more proximal injury = better outcome