Hand

• Scaphoid the most susptible to fracture
• hook of hamate fracture affects ulnar nerve
• lunate is the most dislocated
• Proximal bones

  Scaphoid lunate triquetrum pisiform

  Distal bones

  Trapezium trapezoid capitate hamate
• The radiocarpal joint is an ellipsoid biaxial joint
• 2 articular surfaces

  1. Proximal >inferior surface of radius and triangular disc of inferior radioulnar joint (concave)
  2. Distal articular surface > proximal surfaces of scaphoid triquetral and lunate bones (convex)
• Ligaments of Wrist joint

  1. Joint capsule
  2. Palmar radiocarpal > radius to two rows of carpals > supination
  3. Dorsal radiocarpal > pronation
  4. Ulnar collateral ligament > ulnar styloid to triquetrum
  5. Radial collateral > radial stylod to scaphoid
• Flexion of wrist

  Flexor carpi radialis and ulnaris + palmaris longus
• Adduction of Joint

  Flexor carpi ulnaris and extensor carpi ulnaris
• Extension of wrist

  Extensor carpi raidalis longus + brevis and extensor carpi ulnaris
• Abduction of wrist

  Flexor carpi radialis

  Extensor carpi raidlias longus and brevis

  Abductor pollicis longus
• Articular surfaces of radiocarpal joint: distal surface of radius and articular disc, proximal surfaces of scaphoid, lunate and triquetral of the proximal row of carpal bones
• Midcarpal joint is a complex synovial joint
• Articular surfaces of midcarpal joint: distal surfaces of scaphoid, lunate and triquetral with proximal surfaces of trapezium, trapezoid, capitate and hamate
• Ligaments of midcarpal joint

  Palmar and dorsal intercarpal

  Radial and ulnar collateral
• Blood supply of scaphoid is in distal half
• Carpometacarpal joints - 1st joint metcarpal and trapezium (saddle joint) allows thumb to do

  1. adduction - abduction
  2. Opposition- reposition
• Metacarpophalangeal joints

  They are condyloid (ellipsoid joints) for

  1. Flextion - extension
  2. Abduction- adduction
  3. circumduction
• Interphalangeal joints (thumb) > synovial hinge joints allow only flexion and extension surrounding ligaments prevent other movements
• Dupuytrens Contracture > localised fibrosis and shortening of the palmar aponeurosis which pulls the MP and PIP joint of 4th finger and sometimes 5th into flextion (DIP not involved!) caused by constant vibration
• Flexor retinaculum attached

  1. laterally to scaphoid and trapezium
  2. Medially hook of hamate and pisiform

  Contains median nerve and (4 FDP and 4 FDS) and flexor pollicis longus
• Flexor synovial sheaths

  4 digital synovial sheaths

  2 bursas in palm

  3 seperate synovial sheaths at the wrist

  2nd 3rd and 4th are not connected to main synovial sheath
• Synovial cysts flexion makes the cyst larger
• Hand infections little finger and thumb can carry infection to forearm due to the synovial sheaths being connected
• Long flexor Tendons > FDP (Distal phalanges) + FDS (middle phalanges) are attached to phalanges
• FDS flexes the PIP joints
• FDP flexes the DIP
• Flexion of interphalangeal joints by

  1. FDS> PIP
  2. FDP > DIP
• Extension of Interphalangeal joints

  1. Extensor digitorum
  2. Lumbricals
  3. Interossei
  4. Extensors indicis
  5. Extensor digit minimi
• Mallet Finger

  1. DIP joint bein forced into extreme hyperflexion of distal phalanges
  2. Extensor digitorum gets ruined > cant extend DIP joint
• Thenar muscles (recurrent branch of the median nerve C8-T1)

  A) Opponens pollicis

  B) Adductor pollicis

  C) Flexor pollicis brevis

  D) Abductor pollicis brevis

  
• Adductor pollicis muscle is supplied by deep branch of ulnar C8-T1
• Hypothenar muscles > deep branch of the ulnar nerve(C8-T1)

  A) Abductor digiti minimi

  B) Flexor digiti minimi

  C) Opponens digiti minimi

  
• Short muscles of the hand (Lumbricals)

  1. Flex digits at the MCP and extends at PIP and DIP
  2. Nerve supply: -lateral 2 median side
• Z movements - lumbricals

  Flexs digits at MCP joints adn extend at PIP and DIP
• Palmar interossei muscles (3) > ADDUCT > deep branch of ulnar

  Dorsal interossei muscles (4) > ABDUCT > Ulnar too
• Dermatomes of hand

  C6 - Thumb

  C7 - Middle finger

  C8 - Little finger
• Digital nerves (median)

  Supply skin of lateral 2.5 and nail beds
• Palmar branch doesnt enter carpal tunnel as it supplies the skin of the palm
• bendiction hand (supracondylar fracture) > median nerve damage

  1. loss of flexion and oppostion, weak abduction of thumb, loss of flexion at MCP joints
  2. 3 Digits cant flex