MOD 8 - Overview of Hand Nerve Injuries

Aug 11, 2024

Hand Pathologies Lecture Notes

Overview

  • Discussion of various hand pathologies focusing on nerve, muscle, tendon injuries, and bone fractures.

Median Nerve Palsy

  • Sensation: Affects the first three digits and half of the ring finger.
  • Motor: Innervates most extrinsic muscles and four intrinsic muscles (LOAF: Lumbricals 1 & 2, Opponens pollicis, Abductor pollicis brevis, Flexor pollicis brevis).
  • Symptoms:
    • Difficulty moving the thumb away from the hand (opposition and abduction issues).
    • Thumb is often found close to the other digits (Adductor pollicis still functioning).
    • Limited thumb function, often referred to as "Ape Hand".

Ulnar Nerve Palsy

  • Innervation: Most intrinsic muscles, hypothenar muscles, half of the lumbricals, and interossei muscles. Only a few extrinsic muscles (Flexor carpi ulnaris and half of Flexor digitorum profundus).
  • Sensation: Affects the last two digits (ring and little fingers).
  • Symptoms:
    • Atrophy of the intrinsic muscles.
    • MCP joints in hyperextension, PIP and DIP joints in flexion.
    • Often referred to as "Claw Hand".
    • Loss of motor and sensory function in the fourth and fifth digits.
    • Difficulty with power grip and precision activities.

Radial Nerve Palsy

  • Nerve Path: Radial nerve at upper arm; changes to Posterior Interosseous Nerve (PIN) after passing the elbow joint.
  • Sensation: Affects the dorsal side of the hand.
  • Motor: Extensors of the wrist and fingers.
  • Symptoms:
    • Difficulty with hand extension and making a fist (wrist drop).
    • Extensors are atrophied, flexors are unopposed.
    • Use of wrist splints to support the wrist in a functional position.
    • Common reference to "Drop Hand" or PIN syndrome when related to radial nerve issues.

Summary

  • Understanding the specific nerve involvements can help diagnose and manage various hand pathologies effectively.
  • Treatment often involves supportive splints and rehabilitation exercises to improve hand function.