Lecture Notes: Bones of the Hand

Overview

• Focus on the bones that make up the hand.
• The hand is divided into three major areas:
  • Carpus (wrist)
  • Metacarpus (palm)
  • Phalanges (fingers)

Carpus (Wrist)

• Common Misconception: Wristwatch is worn around the distal ends of the radius and ulna, not the wrist.
• Composed of 8 bones in two irregular rows.
• Proximal Row (lateral to medial, posterior view):
  • Scaphoid: Boat-shaped
  • Lunate: Moon-shaped
  • Triquetrum: Triangle-shaped
  • Pisiform: Pea-shaped (visible in anterior view only)
• Distal Row (lateral to medial):
  • Trapezium: Table-shaped
  • Trapezoid: Four-sided
  • Capitate: Head-shaped
  • Hamate: Hook-shaped

Mnemonic for Carpal Bones

• Proximal Row: "Sally Left The Party"
  • S: Scaphoid, L: Lunate, T: Triquetrum, P: Pisiform
• Distal Row: "To Take Cindy Home"
  • T: Trapezium, T: Trapezoid, C: Capitate, H: Hamate

Wrist Joint

• Formed by:
  • Scaphoid, Lunate, and Triquetrum
• Articulations:
  • Triquetrum articulates with the ulna head
  • Scaphoid and Lunate articulate with the radius
  • Radius and ulna articulate with each other

Metacarpus (Palm)

• Composed of 5 metacarpal bones (numbered I to V with Roman Numerals):
  • I corresponds to the thumb, V to the little finger
• Structure:
  • Base (articulates with carpal bones and adjacent metacarpals)
  • Shaft
  • Head (forms knuckles)
• Notable Feature:
  • Metacarpal I is more anterior and rotated, allowing thumb opposition.

Phalanges (Fingers)

• Numbered 1 through 5 (thumb to little finger)
• Structure:
  • Thumb (Pollex): 2 phalanges (proximal and distal)
  • Other Fingers: 3 phalanges (proximal, middle, distal)

Carpal Tunnel

• Anterior view of carpus is concave, forming the carpal tunnel.
• Contains ligaments, tendons, and the median nerve.
• Carpal Tunnel Syndrome:
  • Inflammation in this area can affect the median nerve, causing pain or tingling, especially at night.