8. Anatomy of the hand Flashcards
What is a common fracture in the hand?
Scaphoid bone
- poor blood supply to proximal part: avascular necrosis- part of the bone dies away
- can take months to heal
Blood supply of the scaphoid bone
radial artery
Radiocarpal joint
Between radius/disc and first carpal row
Reinforced by ligaments
Movement limited by radial and ulnar styloid processes
Saddle joint
between trapezium and d1
enables opposition of thumb
Movements of thumb
extension, flexion, abduction, adduction, opposition, reposition
Carpal Bones
Scaphoid, Lunate, Triquetral, Pisiform, Trapezium, Capitate, Hamate
Metacarpophalangeal joints
Condylar joints
metacarpal bones and the proximal phalanges of the digits
knuckles
Interphalangeal joints
Hinge joints
PIPs, DIPs
Palmar aponeurosis
- Thickened deep fascia
- Triangular
- Continuous with palmaris longus (or flexor retinaculum)
Dupuytren’s contracture is fibrosis of the palmar aponeurosis
What does the Flexor retinaculum do?
prevents bowing of tendons
Contents of the Anatomical snuff box
- Abductor pollicis longus
- Extensor pollicis brevis
- Extensor pollicis longus
- radial artery
- scaphoid bone
- trapezium
Intrinsic muscles of the hand
-insertion
Lumbricals and interossei insert into the extensor hoods
Lumbricals
Link flexor to extensor tendons
- Extend interphalangeal joints and flex MCP joints
- Precision grip (hold pen / pinch)
Interossei
Interossei sit between the metacarpals
Palmer Interossei (3) adduct MCP joint (PAD)
Dorsal Interossei (4)- abduct MCP joint (DAB)
What is the origin of the thenar and hypothenar muscles?
flexor retinaculum and adjacent carpal bones
