Hand anatomy new


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Hand anatomy new

  1. 1. Wrist and Hand Anatomy Moderator: Dr. Asif Sultan Presented by: Qazi Manaan
  2. 2. Overview • The anatomy of the hand is complex, intricate, and fascinating. • Absolutely essential for our everyday functional living.
  3. 3. Bone Anatomy • Total of 27 bones in hand and wrist. • These are grouped into carpals, metacarpals, and phalanges. • The wrist is the most complex joint in the body. It is formed by 8 carpal bones grouped in 2 rows with very restricted motion between them.
  4. 4. • All carpal bones participate in wrist function o except for the pisiform. • The scaphoid serves as link between each row; therefore, it is vulnerable to fractures. • The distal row of carpal bones is strongly attached to the base of the second and third metacarpals, forming a fixed unit.
  5. 5. • The hand contains 5 metacarpal bone. • First Metacarpal articulates proximally with the trapezium. • The other 4 metacarpals articulate with the trapezoid, capitate, and hamate at the base. • The hand contains 14 phalanges.
  6. 6. JOINTS
  7. 7. • All 4 distal carpal bones articulate with the metacarpals at the carpometacarpal (CMC) joints. • At the metacarpophalangeal joints, lateral motion is limited by the collateral ligaments
  8. 8. • At the CMC joint, the volar plate is part of the joint capsule that attaches only to the proximal phalanx, allowing hyperextension. • At the interphalangeal joints:  extension is limited by the volar plate, which attaches to the phalanges at each side of the joint.  Radial and ulnar motion is restricted by collateral ligaments.
  9. 9. Muscles and Tendons
  10. 10. • The muscles of the hand are divided into: Intrinsic and Extrinsic group.
  11. 11. Extrinsic extensors • All extensors are extrinsic and supplied by radial nerve. • Except for the interosseous-lumbrical complex. • Group contains: 3 wrist extensors A larger group of thumb and digit extensors.
  12. 12. • The main extensors at wrist are:  The extensor carpi radialis brevis (ECRB)  extensor carpi radialis longus (ECRL)  extensor carpi ulnaris (ECU)
  13. 13. • At the digits, extension occurs due to: The extensor digitorum communis, extensor indicis proprius, and extensor digiti minimi
  14. 14. • Extension at the thumb is bought about by: The abductor pollicis longus, extensor pollicis brevis, and extensor pollicis longus
  15. 15. Extrinsic Flexors • 3 wrist flexors • A larger group of thumb and digit flexors • Innervated by the median nerve • Except for the FCU, and the FDP to the small and ring finger, which are innervated by the ulnar nerve.
  16. 16. • The main Flexors at the wrist joint are:  The flexor carpi radialis  the flexor carpi ulnaris and  the palmaris longus
  17. 17. • The digital flexors include: Flexor Digitorum Superficialis Flexor Digitorum Profundus Flexor Pollicis Longus
  18. 18. Intrinsics • Situated totally within the hand • Divided into 4 groups: the thenar, hypothenar, lumbrical, and interossei muscles.
  19. 19. • The thenar group consists of:  the abductor pollicis brevis,  flexor pollicis brevis,  opponens pollicis, and  adductor pollicis muscles.
  20. 20. • The hypothenar group consists of:  the palmaris brevis,  abductor digiti minimi,  flexor digiti minimi, and  opponens digiti minimi.
  21. 21. • The lumbrical muscles contribute to  the flexion of the MCP joints and  extension of the interphalangeal joints.
  22. 22. • The interossei group consists of:  3 palmar and  4 dorsal muscles • All innervated by the ulnar nerve.
  23. 23. Zones of the Hand
  24. 24. Flexor Zones
  25. 25. Extensor Zones
  26. 26. NERVES • 3 nerves:  Median  Ulnar  Radial
  27. 27. Median nerve • Crucial in the gripping mechanism by the thumb. • It originates from the lateral and medial cords of the brachial plexus (C5-T1). • In the forearm, the motor branches supply the pronator teres, flexor carpi radialis, palmaris longus, and flexor digitorum superficialis muscles. • The anterior interosseus branch innervates the flexor pollicis longus, flexor digitorum profundus (radial part), and pronator quadratus muscles.
  28. 28. • Palmar cutaneous branch provides sensation at the thenar eminence. Also sensory digital branches provide sensation to the radial three and a half fingers and corresponding palm area • As the median nerve passes through the carpal tunnel, the recurrent motor branch innervates the thenar muscles • It also innervates the index and middle finger lumbrical muscles
  29. 29. Signs of a Lesion: • Benediction Sign :
  30. 30. • Ape Thumb Deformity:
  31. 31. • Median Claw Hand:
  32. 32. Pen Test
  33. 33. Ulnar nerve • Controls fine movement of the fingers • It originates at the medial cord of the brachial plexus (C8-T1) • Sensory to the: hypothenar eminence The palmar and dorsal ulnar one and a half fingers
  34. 34. • The deep motor branch passes through the Guyon canal in company with the ulnar artery. It innervates the  hypothenar muscles  all interossei,  the 2 ulnar lumbricals,  the adductor pollicis, and  the deep head of the flexor pollicis brevis
  35. 35. Signs of a lesion: • Ulnar Claw Hand:
  36. 36. Froment’s Sign
  37. 37. Egawas’ Test
  38. 38. Card Test
  39. 39. Radial nerve • Innervates the wrist extensors. • Originates from the posterior cord of the brachial plexus (C6-8). • At the elbow, motor branches innervate the brachioradialis and extensor carpi radialis longus muscles.
  40. 40. • At the proximal forearm, the radial nerve divides into the superficial and deep branches. • The deep posterior interosseous branch innervates all the muscles in the extensor compartment. • The superficial branch provides sensation at the radial aspect of the dorsum of the hand, the dorsum of the thumb, and the dorsum of the radial three and a half digits proximal to the distal interphalangeal joints.
  41. 41. Signs of a lesion • Wrist Drop
  42. 42. • Loss of Supination:
  43. 43. Blood Supply • Complex and rich vascular network
  44. 44. Radial Artery • Course • A superficial branch arises at the level of the wrist and contributes to the superficial palmar arch. • In the palm it gives off:  Princeps pollicis artery and  Radialis Indicis artery, before terminating in the deep palmar arch.
  45. 45. Ulnar Artery • It travels into the hand through the Guyon canal, where it divides into: • the deep palmar branch and • the superficial palmar branch.
  46. 46. Superficial Palmar Arch • Lies directly deep to the palmar fascia. • It gives rise to the:  volar common digital arteries and  multiple branches to intrinsic muscles and skin. • Distally,the common digital arteries bifurcate into the proper digital arteries.
  47. 47. Deep Palmar Arch • Lies at the base of the metacarpals, deep to the flexor tendons. • From its convexity it gives off three palmar metacarpal arteries. • Dorsally it gives off three perforating arteries. • Recurrent branches arise from the concavity to supply the carpal bones
  48. 48. Dorsal Carpal Arch • Formed by:  the posterior interosseous artery and  a dorsal perforating branch of the anterior interosseous artery. • Dorsal metacarpal arteries arise from a dorsal carpal arch
  50. 50. Veins • Veins generally follow the deep arterial system as venae comitantes. • A superficial venous system also exists at the dorsum of the hand and contributes to the cephalic and basilic veins in the upper extremity.
  51. 51. Deep Fascia • The Flexor Retinaculum • The Palmar Fascia • Fibrous flexor sheaths in fingers • The Extensor Retinaculum
  53. 53. • The Palmar fascia consists of resistant fibrous tissue arranged in longitudinal, transverse, oblique, and vertical fibers. • The transverse fibers are concentrated in the mid palm and web spaces and serve as pulleys for the flexor tendons proximal to the digital pulleys.
  54. 54. •The digits contain 2 fascial bands of clinical importance: the Grayson ligament and the Cleland ligament
  55. 55. Pulley • The pulley system is critical to flexion of the finger. • The retinacular system for each of the fingers contains 5 annular pulleys and 3 cruciate pulleys.
  56. 56. • The thumb has 2 annular pulleys and 1 oblique pulley. • The system supplies mechanical advantage by maintaining the flexor tendons close to the joint's axis of motion. In doing so, the pulleys prevent bowstringing. .
  57. 57. Extensor Retinaculum and the 6 compartments
  58. 58. Compartments of the Hand • 10 separate osteofascial compartments: - dorsal interossei (4 compartments) - palmar interossei (3 compartments) - adductor pollicis - thenar and hypothenar • Typically can be released with carpal tunnel release and 2 dorsal incisions
  59. 59. SKIN
  60. 60. • The skin of the dorsum of the hand is thin and pliable. • It is attached to the hand's skeleton only by loose areolar tissue, where lymphatics and veins course. • explains why edema of the hand is manifested predominantly at the dorsum.
  61. 61. • The skin of the palmar surface of the hand is unique Thick Glabrous Less Pliable • This enhances skin stability for proper grasping function.
  62. 62. • The skin is most firmly anchored to the deep structures at the palmar creases. • Blood supply is through numerous small, vertical branches from the common digital vessels. • High concentration of sensory nerve organs essential to the hand's normal function.
  63. 63. Thank You