Anatomy of nerve injuries upper limb


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Anatomy of nerve injuries upper limb

  1. 1. MOB TCD Anatomy of Nerve Injuries Upper Limb Professor Emeritus Moira O’Brien FRCPI, FFSEM, FFSEM (UK), FTCD Trinity College Dublin
  2. 2. MOB TCD Anatomy of Nerve Injuries • • • • • • Dermatomes Myotomes Nerves entrapped Pierce muscle Pierce fascia Repetitive movements
  3. 3. MOB TCD Dermatomes • • • • • Skin Bones Muscles, tendons Nerves Blood vessels
  4. 4. MOB TCD Cutaneous Supply
  5. 5. MOB TCD Extrinsic Factors • External forces • Fibro-osseous tunnels tether the nerve • Oedema • Callus formation as a result of a fracture • External compression due to specific movements • Mechanical compression • The nerve is tender at the site of compression
  6. 6. MOB TCD Extrinsic Factors • • • • • Fibrous bands Accessory muscles Spurs Narrow notches Anatomical variations of the nerve itself • The most common symptom complex involves the lower trunk of the brachial plexus C8,T1 • With pain and paresthesia along the medial border of the limb
  7. 7. MOB TCD Extrinsic Factors Congenital and structural anomalies include: • Cervical ribs • Scalenus anterior syndrome • Fibrous or fibro-muscular bands
  8. 8. MOB TCD Extrinsic Factors • Costoclavicular, where it may also be • • • • due to anatomical anomalies or structural changes, e.g. shoulder girdle depression Between the pectoralis minor and the coracoid process The shoulder is very mobile and the neurovascular structures may change direction by a full 180° The coracoid process and the pectoralis minor act as a fulcrum for the change in direction This is a potential site of compression
  9. 9. MOB TCD Costoclavicular Compression • Costoclavicular compression is usually dynamic • If you elevate the arm, the clavicle rotates at the sternoclavicular and acromioclavicular joints, narrowing the costoclavicular space • This space will be further narrowed by retraction of the shoulders, particularly if you are carrying a heavy weight • Deep inspiration elevates the first rib; this narrows the space even further
  10. 10. MOB TCD Brachial Plexus • Roots arise from Anterior Primary Rami • C5 • C6 • C7 • C8 • T1 • Contribution from C4
  11. 11. MOB TCD Brachial Plexus • Roots unite to form trunks; posterior triangle of neck • C5, C6 form upper trunk • C7 middle trunk • C8,T1 form lowest trunk • Branches arise mainly from roots and cords • Only 1 from upper trunk
  12. 12. MOB TCD Brachial Plexus • Roots between scalenus anterior and scalenus medius • Trunks in the posterior triangle • Divisions behind clavicle • Cords in axilla to lower border of pectoralis minor
  13. 13. MOB TCD Brachial Plexus
  14. 14. MOB TCD Branches From Roots • Branch to phrenic nerve C5 • Nerve to rhomboids or dorsal scapular C5 • Nerve to subclavius C5,C6, accessory phrenic • Long thoracic nerve to serratus anterior C5, C6, C7 along the side wall of thorax • Kick or blow may affect rotation of scapula and winging of scapula
  15. 15. MOB TCD Brachial Plexus Entrapment • Compression of thoracic inlet • Cervical rib • Scalenus anterior or fibrous band • Back pack narrow costoclavicular
  16. 16. MOB TCD Suprascapular Nerve • Upper trunk of brachial plexus • C5, C6 in the posterior triangle • Passes through suprascapular foramen into the • Supraspinous fossa supplies suprascapular muscle • Passes through the spinoglenoid notch supplies infraspinatus muscle • Articular to shoulder joint
  17. 17. MOB TCD Blood and Nerve Supply • At spinoglenoid notch only infraspinatus affected √
  18. 18. MOB TCD Cords of Brachial Plexus • Outer border of first rib • Divisions unite to form cords • Lateral, medial and posterior cords, related to first and second parts of axillary artery • End at lower border of pectoralis minor
  19. 19. MOB TCD Lateral Cord of Brachial Plexus Lateral cord gives off: • Musculocutaneous • Lateral pectoral • Lateral root of median nerve
  20. 20. MOB TCD Medial Cord of Brachial Plexus • • • • • Medial cutaneous of arm Medial pectoral Medial cutaneous of forearm Medial root of median Ulnar
  21. 21. MOB TCD Posterior Cord of Brachial Plexus • Axillary nerve • Upper subscapular nerve • Lower subscapular nerve, subscapularis and teres major • Nerve to latissimus dorsi • Radial nerve
  22. 22. MOB TCD Musculocutaneous Nerve • Supplies and pierces coracobrachialis • Passes between brachialis and biceps supplying them • Continues as lateral cutaneous of forearm
  23. 23. MOB TCD Lateral Cord of Brachial Plexus • Lateral pectoral pierces the clavipectoral fascia and • Supplies pectoralis major • Gives off the lateral root of median nerve
  24. 24. MOB TCD Axillary Nerve • Posterior cord lower border of pectoralis minor • Quadrilateral space • Upper lateral cutaneous nerve of arm supplies skin over lower half of deltoid • Nerve to deltoid • Nerve to teres minor • Injury results in loss of sensation over the lower half of the deltoid • Weakness of the deltoid and the teres minor
  25. 25. MOB TCD Shoulder Relations Anterior • subscapularis Posterior • infraspinatus, teres minor Superior • long head of biceps • supraspinatus Inferior • axillary nerve In abduction • long head triceps
  26. 26. MOB TCD Shoulder Anterior Relations
  27. 27. MOB TCD Axillary Nerve
  28. 28. MOB TCD Axillary Nerve Compression • Dislocated shoulder • Quadrilateral space
  29. 29. MOB TCD Radial Nerve • In axilla • Posterior cord: lower border of pectoralis minor, posterior to axillary artery • Gives off posterior cutaneous nerve of arm • Supplies and then passes between long and medial head of triceps • Injury in axilla e.g. crutches, Saturday night paralysis
  30. 30. MOB TCD Radial Nerve • In spiral groove • Nerve to lateral and medial head of triceps • Posterior cutaneous nerve of forearm • Nerve to anconeus
  31. 31. MOB TCD Radial Nerve - Spiral Groove • Lies between brachioradialis and brachialis and the extensor carpi radialis longus • Pierces lateral intermuscular septum • Brachioradialis and lateral border of brachialis supplies them • Extensor carpi radialis longus • Divides into superficial branch • Posterior interosseus nerve
  32. 32. MOB TCD Posterolateral • Lies below head of radius • Below lateral epicondyle • Deep or posterior interosseous supplies and then passes between two heads of supinator • Supplies the extensor carpi radialis brevis • Extensors from the lateral epicondyle and all the deep extensors of forearm
  33. 33. MOB TCD Posterior Relations • Superficial lies lateral to radial artery in upper two thirds of forearm • Passes posterior to dorsum • Pierces deep fascia • Supplies posterior aspect of forearm • Skin of dorsum posterior aspect of radial three and half fingers
  34. 34. MOB TCD Radial Nerve in Forearm • Deep or posterior interosseus nerve supplies and then pierces supinator • Muscles of posterior compartment of forearm
  35. 35. MOB TCD Radial Nerve • Extensor digitorum communis, extensor digiti minimi extensor carpi ulnaris • Abductor pollicis longus • Extensor pollicis brevis • Extensor pollicis longus • Extensor indicis
  36. 36. MOB TCD Elbow Nerve Compression • Radial tunnel syndrome • Posterior interosseous nerve syndrome • Cubital tunnel syndrome • Pronator syndrome • Anterior interosseous nerve syndrome Behr & Altchek, 1997
  37. 37. MOB TCD Tennis Elbow Extensor Muscles • Extensor carpi radialis brevis in most cases • Anterior edge of extensor digitorum communis 30% less frequently • Extensor carpi radialis longus • Extensor carpi ulnaris Nirschl, 1993
  38. 38. MOB TCD Posterior Relations of Elbow • • • • Triceps Anconeus Olecranon bursa Ulnar nerve posterior to medial epicondyle • Common extensor origin
  39. 39. MOB TCD Posterior Interosseous
  40. 40. MOB TCD Deep Branch of Radial Nerve Posterior Interosseus • Supplies and then enters forearm between the two heads of supinator • Extensor carpi radialis brevis • Extensor digitorum communis • Extensor indicis • Extensor digiti minimus • Extensor carpi ulnaris • Extensor pollicis longus and brevis • Abductor pollicis longus
  41. 41. MOB TCD Radial Nerve in Forearm and Hand
  42. 42. MOB TCD Radial Nerve in Forearm and Hand
  43. 43. MOB TCD Anatomical Snuffbox Medial • Abductor pollicis longus • Extensor pollicis brevis • Both involved in De Quervain’s syndrome Posterior • Extensor pollicis longus Floor • Distal end of radius and scaphoid • Radial artery Superficial • Radial nerve
  44. 44. MOB TCD Nerves in Forearm • • • • • • Posterior interosseus nerve Supinator Median nerve Pronator teres Ulnar nerve Flexor carpi ulnaris
  45. 45. MOB TCD Median Nerve Median nerve • Lower border of pectoralis minor • Union of the two roots of median • Anterior to axillary artery at first • Then lateral and medial to brachial artery • Passes behind bicipital aponeurosis • No branches in arm • Pronator teres
  46. 46. MOB TCD Median Nerve in Forearm • Median gives off branches to flexor tendons • Pronator teres, flexor carpi radialis • Pronator teres • Flexor digitorium superficialis • Passes between two heads of pronator teres
  47. 47. MOB TCD Median Nerve
  48. 48. MOB TCD Median Nerve • Passes deep to flexor digitorum superficialis • Gives off • Anterior interosseous, supplies flexor pollicis longus • Radial one or two tendons of flexor digitorum profundus • Pronator quadratus
  49. 49. MOB TCD Median Nerve • Median passes deep to flexor digitorum superficialis • At wrist, posterolateral to palmaris longus • Gives off the superficial palmar branch • Passes superficial to flexor retinaculum • Main nerve goes deep to retinaculum
  50. 50. MOB TCD Carpal Tunnel • No loss of sensation over skin of palmar aspect of thenar eminence • Loss over palmar aspect radial 3.5 fingers • Wasting of thenar eminence particularly abductor pollicis brevis
  51. 51. MOB TCD Wrist and Carpal Tunnel
  52. 52. MOB TCD Wrist and Carpal Tunnel • Median distal border gives off motor branch to abductor pollicis brevis • Flexor pollicis brevis • Opponens pollicis • Unipennate lumbricals • Cutaneous branches to radial three and half and skin over the dorsum of corresponding fingers
  53. 53. MOB TCD Injury at Elbow • Loss of sensation over skin of palmar aspect of thenar eminence • Palmar aspect of radial three and half fingers • Wasting of thenar eminence • Weakness of superficialis and one or two of profundus tendons
  54. 54. MOB TCD Median Nerve Lesion
  55. 55. MOB TCD Compartment Syndrome • Forearm is the most common site of compartment syndrome • Anterior compartment of the forearm may compress median nerve • Posterior compartment • Mobile wad may be altered sensation over the dorsum
  56. 56. MOB TCD Compartment Syndrome • Windsurfing may cause compartment syndrome in flexor compartment • Compression of median nerve
  57. 57. MOB TCD Blood and Nerve Supply
  58. 58. MOB TCD Ulnar Nerve • Lower border of pectoralis minor from medial cord • Medial to brachial artery • Midway down • Pierces medial intermuscular septum, into posterior compartment • Passes between two heads of flexor carpi ulnaris • Behind medial epicondyle to enter anterior compartment of forearm • No branches in the arm
  59. 59. MOB TCD Ulnar Nerve
  60. 60. MOB TCD Ulnar Nerve • Supplies and then runs between flexor carpi ulnaris and flexor digitorum profundus • Supplying medial two or three tendons of flexor digitorum profundus • 5 cm above wrist gives off the dorsal cutaneous branch skin of medial one and half fingers
  61. 61. MOB TCD Ulnar Nerve • Passes superficial to flexor retinaculum with artery on lateral side, Guyons’ tunnel • Supplies palmaris brevis • Muscles of hypothenar eminence • Bipennate lumbricals • Palmar and dorsal interossei • Ends in adductor pollicis
  62. 62. MOB TCD Ulnar Nerve
  63. 63. MOB TCD Ulnar Nerve
  64. 64. MOB TCD Ulnar Nerve Compression at wrist affects skin over palmar small finger, half of the ring finger and hypothenar muscles, not skin over the dorsal aspect.
  65. 65. MOB TCD Ulnar Nerve Injury • Rounded elbow in throwing sports • Javelin • Discus puts tension on ulnar nerve at elbow • Electric shock along course of nerve • Late result of supracondylar fracture
  66. 66. MOB TCD Hamate • Hook of hamate may fracture if palm hits a wall • Damage deep branch of ulnar • Wasting of adductor pollicis • 1st dorsal interossei
  67. 67. MOB TCD Ulnar Nerve Paradox • More deformity with an injury at wrist than elbow • Wasting of first web and guttering due to wasting of interossei and bilateral lumbricals • Hyperextension of metacarpophalangeal joints • Flexion of proximal and distal interphalangeal joints
  68. 68. MOB TCD Grips
  69. 69. MOB TCD Test for Ulnar Neuritis • Tap ulnar nerve on posteromedial aspect of medial epicondyle • Completely flex elbow and hold for five minutes • Positive is tingling along nerve Anderson & Hall, 1995
  70. 70. MOB TCD Test for Medial Epicondylitis • • • • Stabilise flexed elbow Palpate medial epicondyle Slowly supinate the forearm Extend wrist and elbow, while patient resists Anderson & Hall, 1995
  71. 71. MOB TCD Elbow • • • • • Biceps brachii Brachialis Triceps Pronator teres Supinator Anderson & Hall, 1995 Musculocutaneous C5,C6 Musculocutaneous C5,C6 Radial C6, C7, C8 Median C6,C7 Posterior interosseous C5,C6
  72. 72. “BMJ Publishing Group Limited (“BMJ Group”) 2012. All rights reserved.”