Hand & Wrist Surgery

The Hand and Wrist: Bones, Ligaments, and Their Functions

Structure of the Hand and Wrist

• The hand and wrist are intricate structures composed of bones, ligaments, and tendons that allow for a wide range of motion and dexterity. The wrist connects the hand to the forearm, essential for movements like gripping, lifting, and rotating.

Bones of the Hand and Wrist

• Carpal Bones: Eight small bones forming the wrist, arranged in two rows.
• Proximal Row: Scaphoid, Lunate, Triquetrum, Pisiform.
• Distal Row: Trapezium, Trapezoid, Capitate, Hamate.
• Metacarpal Bones: Five bones forming the middle part of the hand, each connected to a finger.
• Phalanges: Finger bones. Each finger has three phalanges (proximal, middle, distal), except for the thumb, which has two (proximal, distal).

Major Ligaments of the Wrist

• Radial Collateral Ligament: Stabilizes the wrist and prevents excessive side-to-side movement.
• Ulnar Collateral Ligament: Also stabilizes the wrist on the pinky side.
• Dorsal Radiocarpal Ligament: Controls wrist extension.
• Palmar Radiocarpal Ligament: Controls wrist flexion.

Wrist Movements

• Flexion: Bending the wrist forward.
• Extension: Bending the wrist backward.
• Radial Deviation: Moving the wrist towards the thumb side.
• Ulnar Deviation: Moving the wrist towards the pinky side.
• Pronation: Rotating the forearm so the palm faces downward.
• Supination: Rotating the forearm so the palm faces upward.

Finger Movements

• Flexion and Extension: Bending and straightening the fingers.
• Abduction and Adduction: Spreading the fingers apart and bringing them together.
• The Scaphoid Bone: Located near the base of the thumb, the scaphoid bone is commonly fractured and plays a crucial role in wrist stability and motion.
• The Lunate Bone: Situated in the center of the proximal row of carpal bones, the lunate bone is involved in wrist flexion and extension.
• The Triquetrum Bone: Found next to the lunate, the triquetrum helps stabilize the ulnar side of the wrist.
• The Pisiform Bone: A small, pea-shaped bone sitting on top of the triquetrum, serving as an attachment point for ligaments and tendons.
• The Trapezium Bone: Located near the base of the thumb, the trapezium allows for a wide range of thumb movements.
• The Trapezoid Bone: A small bone next to the trapezium, helping stabilize the base of the index finger.
• The Capitate Bone: The largest carpal bone, situated in the center of the wrist, is key for wrist motion.
• The Hamate Bone: Recognizable by its hook-like projection, the hamate bone is involved in the movement and stability of the ring and pinky fingers.
• The Role of Tendons: Tendons connect muscles to bones, enabling motion. The tendons in the wrist and hand control movements such as gripping and finger flexion/extension.