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Lower Extremity Regional Anesthesia
- 1. BFSA Slide by Brian F S Allen BFSA BFSA BFSA Slide by Brian F S Allen BFSA BFSA Lower Extremity Regional Anesthesia Brian Allen 09/2015
- 2. BFSA Slide by Brian F S Allen BFSA BFSA Scalp* (U,P){2} Interscalene (S,L){2} Transgluteal Sciatic (L,P){4,6} Paravertebral (U,L){4,6} Thoracic Epidural (U,L){4,6} Lumbar Plexusā (L){4,6} TAP (S){4} Superficial Cervical Plexus* (S){2} Axillary* (S,A){2} Infraclavicular (S,A){4} Supraclavicular (S){2} Lumbar Epidural (U,L){4,6} Infragluteal Sciatic (S,L,P){4,6} Ankle* (S){2} Lat Fem Cut* (S){2,4} Popliteal Sciatic (S,L,P){4} Femoral (S){2,4} Obturator* (S){4} Saphenous (S,P){4} HEENT*{2} Wrist* (S){2} Legend: * = Only Single Shot Bold = May Place Catheter Underline = uncommonly done ā = Nerve Stimulator always used Positioning ( ): S = Supine U = Sitting Up P = Prone L = Lateral Decubitus or Simms A = Arm Over Head Needle Length { in inches } Common Regional and Neuraxial Blocks Suprascapular* (U){2,4} Spinal (U,L){3.5,6} Parasacralā (L){4,6}
- 3. BFSA Slide by Brian F S Allen BFSA BFSA Lumbosacral PlexusLumbar Plexus Caudad to: Lumbosacral Plexus Cephalad to: Lumbar Plexus Lateral Femoral Cutaneous N. Ilioinguinal N. Iliohypogastric N. Femoral N. Obturator N. Sciatic N. L1 to L4 L4 to S3
- 4. BFSA Slide by Brian F S Allen BFSA BFSA Lumbar Plexus Parasacral Femoral Saphenous Lateral Femoral Cutaneous Obturator Ankle High Sciatic (Anterior, Transgluteal, Infragluteal) Popliteal Sciatic Tibial Peroneal
- 5. BFSA Slide by Brian F S Allen BFSA BFSA Lumbar Plexus Parasacral Femoral Saphenous Lateral Femoral Cutaneous Obturator Ankle High Sciatic (Anterior, Transgluteal, Infragluteal) Popliteal Sciatic Tibial Peroneal Hip, Thigh, Knee Thigh, Knee, Calf Foot Knee, Calf, Foot
- 6. BFSA Slide by Brian F S Allen BFSA BFSA Lumbar Plexus Parasacral Femoral Saphenous Lateral Femoral Cutaneous Obturator High Sciatic (Anterior, Transgluteal, Infragluteal) Popliteal Sciatic These blocks cover: Ā¾ of the Thigh Ā¼ of the Calf Ā¾ of the Calf Ā¼ of the Thigh
- 7. BFSA Slide by Brian F S Allen BFSA BFSA Lower Extremity Exam: 4 Pās Pinch Lateral Femoral Cutaneous N. Push Sciatic (Tibial) N. Pull Obturator N. Punt Femoral N.
- 8. BFSA Slide by Brian F S Allen BFSA BFSA Lower Extremity Dermatomes L2 L3 L4 L5 S1 S2 S3 S1 L5 L4 L4 L5 L5 L3 L2 L1 L3 S1 S2 L5 L5 L1
- 9. BFSA Slide by Brian F S Allen BFSA BFSA Lower Extremity Osteotomes Femoral N Obturator N Common Peroneal N Tibial N
- 10. BFSA Slide by Brian F S Allen BFSA BFSA Lumbar Plexus Surface Anatomy Palpate: Iliac Crest Draw: Intercristal Line
- 11. BFSA Slide by Brian F S Allen BFSA BFSA Lumbar Plexus Surface Anatomy Palpate: Spinous Processes Draw: Midline
- 12. BFSA Slide by Brian F S Allen BFSA BFSA Lumbar Plexus Surface Anatomy Palpate: PSIS Draw: Line thru PSIS parallel to midline
- 13. BFSA Slide by Brian F S Allen BFSA BFSA Lumbar Plexus Surface Anatomy Measure: 2/3rds distance from midline to PSIS line Mark: This site along intercristal line 5 cm
- 14. BFSA Slide by Brian F S Allen BFSA BFSA Lumbar Plexus Surface Anatomy Needle Insertion Site 3-4 cm
- 15. BFSA Slide by Brian F S Allen BFSA BFSA Transverse Process Lamina ObtN FN LFCN LFCN Fem N Ob N Quadratus Femoris Psoas Genitofemoral N Sympathetics ~2 cm Needle Insertion
- 16. BFSA Slide by Brian F S Allen BFSA BFSA Lumbar Plexus Side Effects, Complications Common ā¢ Epidural Spread +/- Hypotension Rare ā¢ Retroperitoneal Hematoma Contraindications ā¢ Anticoagulation ā¢ Observe same guidelines as with spinal or epidural
- 17. BFSA Slide by Brian F S Allen BFSA BFSA Lumbar Plexus Neurostimulation Neurostimulation ā goal 0.5-1.0 mA ā¢ Expected: Quadriceps (Rarely Obturator) ā¢ Unfavorable: ā Local Twitch = Paraspinous muscles ā Pelvic tilt = Quadratus Lumborum (Needle too lateral) ā Hip Flexion = Psoas (Needle too deep) ā Hamstrings twitch = L4, L5 root (Needle too medial or caudal) Joint Analgesia
- 18. BFSA Slide by Brian F S Allen BFSA BFSA Lumbar Plexus Block Success Weak/Numb in 3 nerves Pull - Obturator N. Pinch - LFCN Punt - Femoral N.
- 19. BFSA Slide by Brian F S Allen BFSA BFSA Parasacral Surface Anatomy Palpate: PSIS Mark: PSIS
- 20. BFSA Slide by Brian F S Allen BFSA BFSA Parasacral Surface Anatomy Palpate: Ischial Tuberosity Draw: Line from PSIS to Ischial Tuberosity
- 21. BFSA Slide by Brian F S Allen BFSA BFSA Parasacral Surface Anatomy Measure: 6 cm caudal to PSIS along line Mark: Needle insertion site 6 cm
- 22. BFSA Slide by Brian F S Allen BFSA BFSA Parasacral Neurostimulation Neurostimulation ā¢ Expected: Foot ā¢ Eversion or Dorsiflexion ā¢ Lateral aspect of N. ā¢ Inversion or Plantarflexion ā¢ Medial aspect of N. ā¢ Either pattern acceptable ā¢ Unfavorable: ā¢ Hamstring, Gluteus Max Joint Analgesia
- 23. BFSA Slide by Brian F S Allen BFSA BFSA Transgluteal Sciatic Surface Anatomy Palpate: PSIS Mark: PSIS
- 24. BFSA Slide by Brian F S Allen BFSA BFSA Transgluteal Sciatic Surface Anatomy Palpate: Greater Trochanter Draw: Line from PSIS to Greater Trochanter
- 25. BFSA Slide by Brian F S Allen BFSA BFSA Transgluteal Sciatic Surface Anatomy Measure: Ā½ distance along line Mark: Midpoint of line
- 26. BFSA Slide by Brian F S Allen BFSA BFSA Transgluteal Sciatic Surface Anatomy Draw: 4 to 5 cm Perpendicular line thru PSIS-GT line midpoint 4 to 5 cm Labat approach
- 27. BFSA Slide by Brian F S Allen BFSA BFSA Transgluteal Sciatic Surface Anatomy Palpate: Sacral Hiatus Draw: Line from Sacral Hiatus to Greater Trochanter
- 28. BFSA Slide by Brian F S Allen BFSA BFSA Transgluteal Sciatic Surface Anatomy Needle Insertion: Where lines intersect Winnie approach
- 29. BFSA Slide by Brian F S Allen BFSA BFSA Transgluteal Sciatic Neurostimulation ? Neurostimulation ā¢ Expected: Foot ā¢ Eversion or Dorsiflexion ā¢ Lateral aspect of N. ā¢ Inversion or Plantarflexion ā¢ Medial aspect of N. ā¢ Either pattern acceptable ā¢ Unfavorable: Proximal (hamstring), Gluteus Max (too superficial), Quad (too deep) Joint Analgesia
- 30. BFSA Slide by Brian F S Allen BFSA BFSA Infragluteal Sciatic Surface Anatomy Draw: Line between them Palpate: Ischial Tuberosity Palpate: Greater Trochanter
- 31. BFSA Slide by Brian F S Allen BFSA BFSA Infragluteal Sciatic Surface Anatomy Measure: Ā½ distance along line Mark: Midpoint of line
- 32. BFSA Slide by Brian F S Allen BFSA BFSA Infragluteal Sciatic Surface Anatomy 4 cm Draw: 4 to 5 cm Perpendicular line thru IT-GT line midpoint
- 33. BFSA Slide by Brian F S Allen BFSA BFSA Infragluteal Sciatic Surface Anatomy Confirmation: Needle insertion is 10 cm off midline Needle Insertion 10 cm
- 34. BFSA Slide by Brian F S Allen BFSA BFSA Infragluteal Sciatic Neurostimulation Neurostimulation ā¢ Expected: Foot ā¢ Eversion or Dorsiflexion ā¢ Lateral aspect of N. ā¢ Inversion or Plantarflexion ā¢ Medial aspect of N. ā¢ Either pattern acceptable ā¢ Unfavorable: Proximal (hamstring), Gluteus Max (too superficial), Quad (too deep) ? Joint Analgesia
- 35. BFSA Slide by Brian F S Allen BFSA BFSA High Sciatic Insertion Site Comparison Infragluteal Transgluteal Parasacral Sciatic Nerve
- 36. BFSA Slide by Brian F S Allen BFSA BFSA Femoral Surface Anatomy Quadriceps: Vastus Lateralis, Vastus Medialis Vastus Intermedius Rectus Femoris Inguinal Ligament
- 37. BFSA Slide by Brian F S Allen BFSA BFSA Femoral Surface Anatomy Iliopsoas Pectineus Sartorius
- 38. BFSA Slide by Brian F S Allen BFSA BFSA Femoral Surface Anatomy Acronym: NAVEL to the Navel Femoral N. Femoral A. Femoral V. Saphenous N.
- 39. BFSA Slide by Brian F S Allen BFSA BFSA Femoral Surface Anatomy Palpate Femoral Artery Needle Insertion 1 cm lateral to Femoral pulse for nerve stim approach
- 40. BFSA Slide by Brian F S Allen BFSA BFSA Femoral Surface Anatomy Ultrasound Probe
- 41. BFSA Slide by Brian F S Allen BFSA BFSA MedialLateral Femoral
- 42. BFSA Slide by Brian F S Allen BFSA BFSA FA Iliopsoas MedialLateral Femoral
- 43. BFSA Slide by Brian F S Allen BFSA BFSA Femoral FA Iliopsoas Fascia Lata MedialLateral Fascia Iliaca
- 44. BFSA Slide by Brian F S Allen BFSA BFSA FA MedialLateral Femoral
- 45. BFSA Slide by Brian F S Allen BFSA BFSA In Plane Needle Approach MedialLateral Femoral FA
- 46. BFSA Slide by Brian F S Allen BFSA BFSA In Plane Needle Approach Avoid Nerve, Pierce Fascia MedialLateral Femoral FA
- 47. BFSA Slide by Brian F S Allen BFSA BFSA Out of Plane Needle Approach MedialLateral Femoral FA
- 48. BFSA Slide by Brian F S Allen BFSA BFSA Out of Plane Needle Approach In Practice, Only Needle Tip Visible MedialLateral Femoral FA
- 49. BFSA Slide by Brian F S Allen BFSA BFSA Femoral Neurostimulation, Block Success Neurostimulation ā¢ Expected: Quad (Patella) ā¢ Unfavorable: ā¢ Sartorius (too medial or superficial ā¢ Adduction (too deep or Anterior Division of Fem N.) ā¢ Block Success: ā¢ Quad Weak ā¢ Punt Joint Analgesia
- 50. BFSA Slide by Brian F S Allen BFSA BFSA Saphenous Surface Anatomy Adductor Canal Adductor Canal Contents: Femoral Nerve, Artery, Vein sandwiched between Sartorius and Adductors
- 51. BFSA Slide by Brian F S Allen BFSA BFSA Saphenous Surface Anatomy Ultrasound Probe A block anywhere along Adductor Canal can be called: Subsartorial, Periarterial, or Adductor Canal Saphenous Block
- 52. BFSA Slide by Brian F S Allen BFSA BFSA MedialLateral
- 53. BFSA Slide by Brian F S Allen BFSA BFSA MedialLateral FA FV
- 54. BFSA Slide by Brian F S Allen BFSA BFSA MedialLateral FA Sartorius Adductor Longus Vastus Medialis
- 55. BFSA Slide by Brian F S Allen BFSA BFSA MedialLateral FA Saph N? Saph N?
- 56. BFSA Slide by Brian F S Allen BFSA BFSA MedialLateral FA
- 57. BFSA Slide by Brian F S Allen BFSA BFSA MedialLateral FA Ideal Periarterial Spread
- 58. BFSA Slide by Brian F S Allen BFSA BFSA Saphenous Surface Anatomy Femoral Artery penetrates dorsally thru Adductor Magnus, becoming the Popliteal Artery, marking the distal end of the adductor canal
- 59. BFSA Slide by Brian F S Allen BFSA BFSA Saphenous Surface Anatomy Descending Geniculate Artery
- 60. BFSA Slide by Brian F S Allen BFSA BFSA Saphenous Surface Anatomy A block distal to Adductor Canal is called: Subsartorial Saphenous Block NOT called Periarterial or Adductor Canal Block Ultrasound Probe
- 61. BFSA Slide by Brian F S Allen BFSA BFSA MedialLateral
- 62. BFSA Slide by Brian F S Allen BFSA BFSA MedialLateral Sartorius
- 63. BFSA Slide by Brian F S Allen BFSA BFSA MedialLateral Saph N. ?
- 64. BFSA Slide by Brian F S Allen BFSA BFSA MedialLateral Ideal Fascial Spread
- 65. BFSA Slide by Brian F S Allen BFSA BFSA Saphenous Neurostimulation, Block Success Neurostimulation ā not typically used ā¢ Expected: No motor response, only Medial Calf Paresthesia Block Success: ā¢ No motor weakness ā¢ Sensory only ?Joint Analgesia
- 66. BFSA Slide by Brian F S Allen BFSA BFSA Lateral Femoral Cutaneous Surface Anatomy Inguinal Ligament Anterior Superior Iliac Spine
- 67. BFSA Slide by Brian F S Allen BFSA BFSA Lateral Femoral Cutaneous Surface Anatomy Anterior Superior Iliac Spine LFCN Needle Insertion: 2 cm medial and caudal to ASIS Medial & superficial to Sartorius
- 68. BFSA Slide by Brian F S Allen BFSA BFSA Lateral Femoral Cutaneous Surface Anatomy Needle Insertion Needle Insertion: 2 cm medial and caudal to ASIS Medial & superficial to Sartorius
- 69. BFSA Slide by Brian F S Allen BFSA BFSA Lateral Femoral Cutaneous Surface Anatomy Ultrasound Probe Needle Insertion: 2 cm medial and caudal to ASIS Medial & superficial to Sartorius
- 70. BFSA Slide by Brian F S Allen BFSA BFSA LFCN Neurostimulation, Block Success Neurostimulation ā¢ Expected: No motor response, only Lateral Thigh Paresthesia Block Success: ā¢ No motor weakness ā¢ Sensory only
- 71. BFSA Slide by Brian F S Allen BFSA BFSA Obturator Surface Anatomy
- 72. BFSA Slide by Brian F S Allen BFSA BFSA Obturator Surface Anatomy Iliopsoas Pectineus Adductor Magnus
- 73. BFSA Slide by Brian F S Allen BFSA BFSA Obturator Surface Anatomy Iliopsoas Pectineus Adductor Brevis Adductor Magnus
- 74. BFSA Slide by Brian F S Allen BFSA BFSA Obturator Surface Anatomy Iliopsoas Pectineus Adductor Brevis Adductor Longus Adductor Magnus
- 75. BFSA Slide by Brian F S Allen BFSA BFSA Obturator Surface Anatomy ā¢3+ branches of Obturator Nerve (highly variable) ā¢Anterior ā runs between Brevis & Longus ā¢Posterior ā between Longus & Magnus ā¢Hip Branch ā¢Anterior Branch: Innervates Adductor Longus, Brevis, Gracilis ā¢Posterior Branch: Innervates Adductor Brevis, Magnus, Obturator Externus, Knee Joint ā¢Hip Branch: Innervates part of Hip Joint
- 76. BFSA Slide by Brian F S Allen BFSA BFSA Obturator Neurostimulation, Block Success Neurostimulation ā¢ Expected: Adduction Block Success: ā¢ Pull ā Obturator ā¢ Sensory highly variable ā¢ Only 50% have any detectable skin surface numbness Joint Analgesia 50%
- 77. BFSA Slide by Brian F S Allen BFSA BFSA Anterior Sciatic Surface Anatomy Greater Trochanter Lesser Trochanter Femur Anterior Superior Iliac Spine
- 78. BFSA Slide by Brian F S Allen BFSA BFSA Anterior Sciatic Surface Anatomy Pubic Tubercle Pubic Symphysis
- 79. BFSA Slide by Brian F S Allen BFSA BFSA Anterior Sciatic Surface Anatomy Sciatic Nerve Common Peroneal Tibial
- 80. BFSA Slide by Brian F S Allen BFSA BFSA Anterior Sciatic Surface Anatomy
- 81. BFSA Slide by Brian F S Allen BFSA BFSA Anterior Sciatic Surface Anatomy Draw: Line between ASIS & Pubic Tubercle
- 82. BFSA Slide by Brian F S Allen BFSA BFSA Anterior Sciatic Surface Anatomy Divide ASIS-PT line into thirds
- 83. BFSA Slide by Brian F S Allen BFSA BFSA Anterior Sciatic Surface Anatomy Draw: Line perpendicular from medial third of ASIS-PT line to GT line
- 84. BFSA Slide by Brian F S Allen BFSA BFSA Anterior Sciatic Surface Anatomy Draw: Line from Greater Trochanter parallel to ASIS-PT line
- 85. BFSA Slide by Brian F S Allen BFSA BFSA Anterior Sciatic Surface Anatomy Needle Insertion Beck Approach
- 86. BFSA Slide by Brian F S Allen BFSA BFSA Anterior Sciatic Surface Anatomy Needle Insertion Chelly Approach 8 cm
- 87. BFSA Slide by Brian F S Allen BFSA BFSA Anterior Sciatic Neurostimulation Neurostimulation ā¢ Expected: Foot ā¢ Eversion or Dorsiflexion ā¢ Lateral aspect of N. ā¢ Inversion or Plantarflexion ā¢ Medial aspect of N. ā¢ Either pattern acceptable ā¢ Unfavorable: Proximal (hamstring), Gluteus Max (too deep), Quad (too superficial) Joint Analgesia ?
- 88. BFSA Slide by Brian F S Allen BFSA BFSA Popliteal Sciatic Anatomy Popliteal Crease Ischial Tuberosity
- 89. BFSA Slide by Brian F S Allen BFSA BFSA Popliteal Sciatic Anatomy Semimembranosus Biceps Femoris, Short Head
- 90. BFSA Slide by Brian F S Allen BFSA BFSA Popliteal Sciatic Surface Anatomy Semitendinosus Biceps Femoris, Long Head Gastrocnemius
- 91. BFSA Slide by Brian F S Allen BFSA BFSA Popliteal Sciatic Surface Anatomy Popliteal Fossa
- 92. BFSA Slide by Brian F S Allen BFSA BFSA Popliteal Sciatic Surface Anatomy 7 cm proximal to popliteal crease 1 cm lateral to midpoint of popliteal crease Biceps Femoris Tendon Semitendinosus Tendon Needle Insertion for nerve stim approach
- 93. BFSA Slide by Brian F S Allen BFSA BFSA Popliteal Sciatic Surface Anatomy Probe location for Ultrasound approach 7 cm proximal to popliteal crease
- 94. BFSA Slide by Brian F S Allen BFSA BFSA Popliteal Sciatic Surface Anatomy Sciatic N. Common Peroneal N. Tibial N. Popliteal A. Popliteal V.
- 95. BFSA Slide by Brian F S Allen BFSA BFSA Popliteal Sciatic Surface Anatomy Probe location for Ultrasound approach
- 96. BFSA Slide by Brian F S Allen BFSA BFSA Image: Pedro Simoes Note difference in angle Popliteal Sciatic Surface Anatomy
- 97. BFSA Slide by Brian F S Allen BFSA BFSA Image: Pedro Simoes Popliteal Sciatic Surface Anatomy Ultrasound Probe
- 98. BFSA Slide by Brian F S Allen BFSA BFSA Image: Pedro Simoes Popliteal Sciatic Surface Anatomy Ultrasound Probe Biceps Femoris Vastus Lateralis
- 99. BFSA Slide by Brian F S Allen BFSA BFSA Image: Pedro Simoes Popliteal Sciatic Surface Anatomy Ultrasound Probe Biceps Femoris Vastus Lateralis Needle Insertion
- 100. BFSA Slide by Brian F S Allen BFSA BFSA MedialLateral Deep, Ventral Superficial, Dorsal
- 101. BFSA Slide by Brian F S Allen BFSA BFSA MedialLateral Deep, Ventral Superficial, Dorsal Biceps Femoris Semimembranosus
- 102. BFSA Slide by Brian F S Allen BFSA BFSA MedialLateral Deep, Ventral Superficial, Dorsal Sciatic Nerve
- 103. BFSA Slide by Brian F S Allen BFSA BFSA MedialLateral Deep, Ventral Superficial, Dorsal Common Peroneal Tibial
- 104. BFSA Slide by Brian F S Allen BFSA BFSA MedialLateral Deep, Ventral Superficial, Dorsal
- 105. BFSA Slide by Brian F S Allen BFSA BFSA Popliteal Neurostimulation, Block Success Neurostimulation ā¢ Expected: TIP (medial) or PED (lateral) ā¢ TIP ā Tibial N. = Inversion or Dorsiflexion ā¢ PED ā Peroneal N. = Eversion or Plantarflexion Block Success: weakness ā¢ Push - Tibial ā¢ Dorsiflexion - Peroneal Joint Analgesia
- 106. BFSA Slide by Brian F S Allen BFSA BFSA Ankle Block Surface Anatomy Medial Ankle Lateral AnkleImages: Phulvar
- 107. BFSA Slide by Brian F S Allen BFSA BFSA Ankle Block Surface Anatomy Medial Ankle Lateral AnkleImages: Phulvar Lateral Maleolus Medial Maleolus
- 108. BFSA Slide by Brian F S Allen BFSA BFSA Ankle Block Surface Anatomy Medial Ankle Lateral AnkleImages: Phulvar Superficial Nerves
- 109. BFSA Slide by Brian F S Allen BFSA BFSA Ankle Block Surface Anatomy Medial Ankle Lateral Ankle Saphenous N. Images: Phulvar Superficial Nerves Superficial Peroneal N. Sural N.
- 110. BFSA Slide by Brian F S Allen BFSA BFSA Ankle Block Surface Anatomy Medial Ankle Lateral AnkleImages: Phulvar Superficial Nerves Needle Insertion
- 111. BFSA Slide by Brian F S Allen BFSA BFSA Ankle Block Surface Anatomy Medial Ankle Lateral AnkleImages: Phulvar Superficial Nerves
- 112. BFSA Slide by Brian F S Allen BFSA BFSA Ankle Block Surface Anatomy Medial Ankle Lateral AnkleImages: Phulvar Lateral Maleolus Medial Maleolus Deep Nerves
- 113. BFSA Slide by Brian F S Allen BFSA BFSA Ankle Block Surface Anatomy Medial Ankle Lateral AnkleImages: Phulvar Flexor Digitorum Longus Tendon Tibialis Posterior Tendon Deep Nerves
- 114. BFSA Slide by Brian F S Allen BFSA BFSA Ankle Block Surface Anatomy Medial Ankle Lateral AnkleImages: Phulvar Posterior Tibial Artery Posterior Tibial Nerve Deep Nerves
- 115. BFSA Slide by Brian F S Allen BFSA BFSA Ankle Block Surface Anatomy Images: Phulvar Injection Site Deep Nerves Landmark Approach
- 116. BFSA Slide by Brian F S Allen BFSA BFSA Ankle Block Surface Anatomy Images: Phulvar Deep Nerves Ultrasound Approach Ultrasound Probe
- 117. BFSA Slide by Brian F S Allen BFSA BFSA Ankle Block Surface Anatomy Dorsum of the Foot Ankle Sprain
- 118. BFSA Slide by Brian F S Allen BFSA BFSA Ankle Block Surface Anatomy Dorsum of the Foot Extensor Hallucis Longus Tendon Extensor Digitorum Longus Tendon Deep Nerves
- 119. BFSA Slide by Brian F S Allen BFSA BFSA Ankle Block Surface Anatomy Dorsum of the Foot Deep Peroneal Nerve Dorsalis Pedis A. Deep Nerves
- 120. BFSA Slide by Brian F S Allen BFSA BFSA Ankle Block Surface Anatomy Dorsum of the Foot Injection Site Deep Nerves Landmark Approach
- 121. BFSA Slide by Brian F S Allen BFSA BFSA Ankle Block Surface Anatomy Dorsum of the Foot Deep Nerves Ultrasound Approach Ultrasound Probe
- 122. BFSA Slide by Brian F S Allen BFSA BFSA Ankle Block Success Block Success: ā¢ Numbness in 5 terminal nerve distributions
- 123. BFSA Slide by Brian F S Allen BFSA BFSA ā¢ Posterior Tibial ā¢ Plantar Foot ā¢ Deep Peroneal ā¢ Web space between 1st & 2nd toe ā¢ Superficial Peroneal ā¢ Dorsal Foot ā¢ Saphenous ā¢ Medial Calf ā¢ Sural ā¢ Lateral Calf
- 124. BFSA Slide by Brian F S Allen BFSA BFSA Lumbar Plexus Parasacral Femoral Saphenous Lateral Femoral Cutaneous Obturator Ankle High Sciatic (Anterior, Transgluteal, Infragluteal) Popliteal Sciatic Tibial Peroneal Hip, Thigh, Knee Thigh, Knee, Calf Foot Knee, Calf, Foot
- 125. BFSA Slide by Brian F S Allen BFSA BFSA Lumbar Plexus Effect Comparisons Saphenous Ankle ObturatorLat Fem CutFemoralLumbar Plexus 50 %
- 126. BFSA Slide by Brian F S Allen BFSA BFSA Sciatic Block Effect Comparisons ?? ? Popliteal Ankle Anterior SciaticInfraglutealTransglutealParasacral
- 127. BFSA Slide by Brian F S Allen BFSA BFSA Quiz Questions 1. All of the following nerves innervate part of the hip or knee joint EXCEPT: A. Obturator B. Lateral Femoral Cutaneous C. Sciatic D. Saphenous 2. Which nerve, blocked during an ankle block, is a terminal branch of the femoral nerve? A. Sural B. Deep Peroneal C. Saphenous D. Posterior Tibial
- 128. BFSA Slide by Brian F S Allen BFSA BFSA Quiz Questions 3. The most proximal approach to to the sciatic nerve is called what? A. Popliteal sciatic block B. Transgluteal sciatic block C. Parasacral block D. Anterior sciatic block 4. The adductor canal is surrounded by all of the following muscles EXCEPT: A. Vastus medialis B. Rectus femoris C. Adductor longus D. Sartorius
- 129. BFSA Slide by Brian F S Allen BFSA BFSA References ā¢ LE Lecture References by Slide ā¢ Slide 3 ā¢ Clinical Anesthesia 7th Edn. P. G. Barash, B. F. Cullen and R. K. Stoelting (editors). Published by Lippincott, Williams and Wilkins, Philadelphia, USA. 2013 ā¢ ā¢ Slide 7 & 39 ā¢ Enneking F, Chan V, GREGER J, Hadzic A, LANG S, Horlocker T. Lower-extremity peripheral nerve blockade: Essentials of our current understanding. Reg Anesth Pain Med. 2005;30(1):4-35. ā¢ ā¢ Slide 10 ā¢ Capdevila X, Macaire P, Dadure C, et al. Continuous psoas compartment block for postoperative analgesia after total hip arthroplasty: new landmarks, technical guidelines, and clinical evaluation. Anesth Analg. 2002;94(6):1606-1613. ā¢ ā¢ Slide 14 ā¢ Heller AR, Fuchs A, Rƶssel T, et al. Precision of traditional approaches for lumbar plexus block: impact and management of interindividual anatomic variability. Anesthesiology. 2009;111(3):525-532. ā¢ ā¢ Slide 15 ā¢ Ilfeld BM, Loland VJ, Mariano ER. Prepuncture Ultrasound Imaging to Predict Transverse Process and Lumbar Plexus Depth for Psoas Compartment Block and Perineural Catheter Insertion. Anesth Analg. 2010;110(6):1725-1728. ā¢ ā¢ Slide 16 ā¢ Gadsden JC, Lindenmuth DM, Hadzic A, Xu D, Somasundarum L, Flisinski KA. Lumbar plexus block using high-pressure injection leads to contralateral and epidural spread. Anesthesiology. 2008;109(4):683-688. ā¢ ā¢ Slide 21 ā¢ Ripart J, Cuvillon P, Nouvellon E, Gaertner E, Eledjam J. Parasacral approach to block the sciatic nerve: A 400-case survey. Reg Anesth Pain Med. 2005;30(2):193-197. ā¢ ā¢ Slide 21 ā¢ OŹ¼Connor M, Coleman M, Wallis F, Harmon D. An Anatomical Study of the Parasacral Block Using Magnetic Resonance Imaging of Healthy Volunteers. Anesth Analg. 2009;108(5):1708-1712. ā¢ ā¢ Slide 28 ā¢ Brown, D.L. (2010). Sciatic Block in 4th Ed. Atlas of Regional Anesthesia. (pp. 101-110) Philadelphia. Elsevier. ā¢ ā¢ Slide 7 & 39 ā¢ Enneking F, Chan V, GREGER J, Hadzic A, LANG S, Horlocker T. Lower-extremity peripheral nerve blockade: Essentials of our current understanding. Reg Anesth Pain Med. 2005;30(1):4-35. ā¢ ā¢ Slide 49 ā¢ Anns JP, Chen EW, Nirkavan N, McCartney CJ, Awad IT. A Comparison of Sartorius Versus Quadriceps Stimulation for Femoral Nerve Block. Anesth Analg. 2011;112(3):725-731. ā¢ ā¢ Slide 50 ā¢ Jaeger P, Nielsen ZJK, Henningsen MH, Hilsted KL, Mathiesen O, Dahl JB. Adductor canal block versus femoral nerve block and quadriceps strength: a randomized, double-blind, placebo-controlled, crossover study in healthy volunteers. Anesthesiology. 2013;118(2):409-415. ā¢ ā¢ Slide 54 ā¢ Lund J, Jenstrup MT, Jaeger P, SĆørensen AM, Dahl JB. Continuous adductor-canal-blockade for adjuvant post-operative analgesia after major knee surgery: preliminary results. Acta Anaesthesiol Scand. 2010;55(1):14-19. ā¢ ā¢ Slide 60 ā¢ Marian AA, Ranganath Y, Bayman EO, Senasu J, Brennan TJ. A Comparison of 2 Ultrasound-Guided Approaches to the Saphenous Nerve Block. Reg Anesth Pain Med. 2015;40(5):623-630. ā¢ ā¢ Slide 67 ā¢ Brown, D.L. (2010). Lateral Femoral Cutaneous Block in 4th Ed. Atlas of Regional Anesthesia. (pp. 121-124) Philadelphia. Elsevier. ā¢
Editor's Notes
- This talk will cover the essentials of lower extremity regional anesthesia, from an anatomic focus to practical tips about ultrasound or nerve stimulator guided regional anesthesia. It is an extremely broad topic. Some depth will, of necessity, be excluded.
- This reference slide demonstrates the blocks that arte included in this lecture. It also suggests positioning, needle length selection, and whether the block is amenable to catheter placement.
- Innervation of the lower extremity derives from L1 to S3 spinal roots. These roots branch, coalesce, and can be divided for teaching purposes into the lumbar plexus and the lumbosacral plexus. Nerves derived from L1, L2, L3, and L4 comprise the lumbar plexus. The lumbar plexus contains ilioinguinal, iliohypogastric, genitofemoral, femoral, obturator, and lateral femoral cutaneous nerves. The lumbosacral plexus is made of L4, L5, S1, S2, and S3 spinal roots. Most of the lumbosacral plexus coalesces into the sciatic nerve. Small branches form the pudendal nerve and posterior cutaneous nerve of the thigh. Other branches of the lumbosacral plexus or high branches off the sciatic nerve go to the hamstrings, gluteal muscles, and other muscles of the high posterior thigh. The sciatic nerve is composed of two sets of nerve fibers which eventually split in the distal thigh to form tibial and common peroneal nerves. It is worth noting that these fibers are separate from one another for the entire course of the sciatic nerve, but are contained within one sheath until they split. In this way, the tibial nerve fibers are always on the medial aspect of the sciatic nerve and the peroneal are lateral; a fact that has relevance when performing nerve stimulator-guided blocks. Clinical Anesthesia 7th Edn. P. G. Barash, B. F. Cullen and R. K. Stoelting (editors). Published by Lippincott, Williams and Wilkins, Philadelphia, USA. 2013. CCA 3.0 Public Domain
- This schematic shows the major blocks of the lower extremity and their relationship to one another. A lumbar plexus block, described later, should be expected to block femoral, obturator, and lateral femoral cutaneous nerves. The saphenous nerve, a distal continuation of the femoral nerve, would be anesthetized by either a lumbar plexus or femoral block. Likewise, a sciatic block anywhere above the division of the sciatic nerve in the distal thigh should block both tibial and peroneal nerves. An ankle block anesthetizes distal branches of the tibial, peroneal, and saphenous nerves.
- Blocks performed for a given surgery can vary widely by institution and provider preference. Still, as a guideline, proximal blocks are useful for proximal surgeries, and distal blocks are acceptable for distal surgeries.
- As another general rule, the lumbar plexus innervates the anterior, medial, and lateral thigh and medial calf. The sacral plexus innervates the posterior thigh and anterior, lateral, and posterior calf. Thus, blockade of the lumbar plexus (or its branches) is more important for thigh surgery, while sciatic block is more important for calf, foot, or ankle surgery. This also shows that blockade of both lumbar and lumbosacral plexuses are required for complete analgesia of the thigh or the calf, though innervation of most of the foot comes from branches of the sciatic nerve.
- Assessment of success of a lower extremity block should be done in two ways. The sensory distribution of a block should be assessed. This will be discussed in later slides. The motor weakness produced by a block should also be determined. Similar to the upper extremity, remember the mnemonic 4 Pās to remember how to test the main terminal nerves of the lower extremity. The 4 Pās are push, pull, pinch, punt. Push: Foot plantar flexion against resistance tests the tibial portion of the sciatic nerve (dorsiflexion would test the peroneal portion). Pull: Hip adduction against resistance test the obturator nerve. Pinch: Pinch testing the lateral thigh tests the lateral femoral cutaneous nerve (LFCN), which is a purely sensory nerve. Punt: Knee extension against resistance tests the femoral nerve. 1.Enneking F, Chan V, GREGER J, Hadzic A, LANG S, Horlocker T. Lower-extremity peripheral nerve blockade: Essentials of our current understanding. Reg Anesth Pain Med. 2005;30(1):4-35.
- This reference slide shows the dermatomes of the leg. That is, the pattern of skin innervation deriving from each spinal root. Alternatively, this would be the pattern of skin anesthesia you would find if you performed a selective block of a given spinal root. Looking at the front, ventral side of the leg, the lumbar dermatomes appear like ribbons, running diagonally from proximal and lateral to distal and medial. The sacral dermatomes run more vertically up the dorsal leg, with S1 lateral to S2. L1 innervates the groin and high medial thigh, L2, L3, and L4 innervate the anterior thigh and knee, with L4 curling down to cover the medial calf onto the foot and great toe. L5 innervates the lateral calf and top of the foot. Similar to dermatomes in other areas (chest wall, brachial plexus), these dermatomes are a simplification of what would be seen in an individual. Innervation can vary highly between individuals and even within individuals (from one leg or arm to the other). Dermatomes may overlap, and some nerves may have large areas of skin innervation or even no skin innervation. Variation is the rule rather than the exception.
- Osteotomes are the innervation of sections of bone. In the lower extremity, the obturator, femoral, tibial and common peroneal nerves provide this bony innervation. The obturator nerve innervates part of the pelvis and the medial femur. The femoral nerve supplies the remainder of the femur except for its distal, lateral aspect. The tibial and peroneal nerves, branches of the sciatic nerve, innervate the tibia, fibula, and bones of the foot. The exception is the tibial plateau that is supplied by the femoral nerve. There is also some suggestion that the medial ankle may be innervated by the femoral nerve.
- Moving on to specific nerve blocks, we will start with performance of lumbar plexus blockade. This block is commonly done as a nerve stimulator-guided injection. Various approaches have incorporated ultrasound. This takes 2 forms: as a pre-scan to establish anatomy, landmarks, and target depth or as an intraprocedural scan to actively guide needle placement. The approach here described will not use ultrasound. Place the patient in Simās position, with the operative side up, with the operative hip and knee flexed and the non-operative (down) side straight. Start by palpating the patientās iliac crests. Draw a line connecting the tops of the iliac crests. Capdevila X, Macaire P, Dadure C, et al. Continuous psoas compartment block for postoperative analgesia after total hip arthroplasty: new landmarks, technical guidelines, and clinical evaluation. Anesth Analg. 2002;94(6):1606-1613.
- Find midline by palpating spinous processes. Draw a line along midline.
- Palpate the posterior superior iliac spine. Draw a line through the PSIS that parallels the midline. Note where this line contacts the intercristal line.
- At this point, several described approaches to the lumbar plexus diverge. The distance from the midline laterally to the PSIS is well conserved in adults and is independent of BMI. It is usually 5 cm. Early approaches to the lumbar plexus (cite) recommended starting at the intersection of the PSIS and intercristal lines. A later approach describes an insertion site two thirds of the way from midline to the intersection with the PSIS line along the intercristal line.
- This 2/3rds of the way along the line ends up being 3-4 cm off midline. 1.Heller AR, Fuchs A, Rƶssel T, et al. Precision of traditional approaches for lumbar plexus block: impact and management of interindividual anatomic variability. Anesthesiology. 2009;111(3):525-532.
- The needle insertion site produced by the previous landmark method would look like this in transverse section. The needle is inserted at the level of L4, superficial to the transverse process. The needle is advanced from posterior to anterior in a parasaggital plane, perpendicular to the skin on the back in all planes. Contact with bone should be sought, which should be L4 transverse process. The needle is withdrawn, angled slightly caudal, and advanced. If bone is not contacted, the needle is advanced approximately 2 cm past the depth at which bone had been contacted. The nerve stimulator is used throughout and the patellar snap of quadriceps contraction is sought. The nerves of the lumbar plexus are variably located within the psoas muscle. Ultrasound imaging can be useful in locating transverse process and its depth. 1.Ilfeld BM, Loland VJ, Mariano ER. Prepuncture Ultrasound Imaging to Predict Transverse Process and Lumbar Plexus Depth for Psoas Compartment Block and Perineural Catheter Insertion. Anesth Analg. 2010;110(6):1725-1728.
- Aside from standard procedural risks such as infection, damage to surrounding structures, block failure, and systemic toxicity, lumbar plexus blocks have a high risk of epidural spread (cite). Medial needle angulation, high injection pressure, and high injection volume make epidural spread more likely. There have been reports of retroperitoneal hematomas occurring after lumbar plexus block, especially in anticoagulated patients. For that reason, lumbar plexus block should be treated just like neuraxial or other deep plexus blocks when adhering to anticoagulation guidelines. 1.Gadsden JC, Lindenmuth DM, Hadzic A, Xu D, Somasundarum L, Flisinski KA. Lumbar plexus block using high-pressure injection leads to contralateral and epidural spread. Anesthesiology. 2008;109(4):683-688.
- The image above shows the distribution of sensory analgesia expected from successful lumbar plexus block. Hamstring or calf twitches suggest the needle tip is too medial or caudal, catching the L4 or L5 root. Local twitch of the back muscles suggest too superficial a needle. A rocking motion of the hips, which can look like a pulling of the leg without patellar snap, is suggestive of a needle that is too lateral, located in the quadratus femoris.
- Successful lumbar plexus block should produce a numb lateral and anterior thigh, weakness of knee extension and hip adduction. Branches of the obturator nerve innervate portions of the hip and knee joint. The femoral nerve also sends articular branches to the knee.
- The parasacral nerve block is the most proximal approach that can block the sciatic nerve outside of the neuraxis. Initially, place the patient in Simās position. Palpate and mark the PSIS.
- Next, palpate the ischial tuberosity. Draw a line between PSIS and ischial tuberosity.
- Mark a point 6 cm caudal to the PSIS along the PSIS/Ischial tuberosity (IT) line. Insert the needle, with stimulator connected, perpendicular to the skin in all planes. Sciatic nerve response is sought, either with foot plantar flexion (tibial nerve) or foot dorsiflexion (common peroneal). If bone is encountered, remove the needle and place it 1 cm more caudal along the PSIS/IT line. Do NOT advance more than 2.5 cm beyond the depth at which bone was previously contacted. Advancing too deep can lead to injury to the rectum, ovary, or other pelvic structures. Ripart J, Cuvillon P, Nouvellon E, Gaertner E, Eledjam J. Parasacral approach to block the sciatic nerve: A 400-case survey. Reg Anesth Pain Med. 2005;30(2):193-197. Ā OŹ¼Connor M, Coleman M, Wallis F, Harmon D. An Anatomical Study of the Parasacral Block Using Magnetic Resonance Imaging of Healthy Volunteers. Anesth Analg. 2009;108(5):1708-1712.
- The parasacral block is the most proximal block of the sciatic nerve and carries the benefit of covering nerves to the hamstring muscles, the posterior cutaneous nerve of the thigh (which innervates the skin of the back of the thigh), and articular branches to the hips, knee, and ankle. Nerve stimulation is used for block performance. Distal twitch of tibial or peroneal nerves is ideal. Proximal twitches are not ideal.
- The transgluteal sciatic nerve block is performed slightly distal to the parasacral block. The PSIS is palpated and marked.
- Next, palpate the greater trochanter (GT) of the femur and draw a line connecting PSIS to GT.
- Find and mark the midpoint of the PSIS/GT line
- Drop a perpendicular line from the midpoint of the PSIS/GT line. This line should be 5 cm. These landmarks designate the Labat approach to the sciatic nerve. This is modified and confirmed in the Winnie approach.
- Palpate the sacral hiatus and draw a line between the sacral hiatus (SH) and greater trochanter. This SH/GT line should contact the perpendicular line drawn in the previous step.
- Needle insertion occurs at the intersection of these lines. Use of this confirmatory SH/GT line for the transgluteal sciatic block is called the Winnie approach. The needle is inserted perpendicular to the skin in all planes and again, a distal twitch is sought. Brown, D.L. (2010). Sciatic Block in 4th Ed. Atlas of Regional Anesthesia. (pp. 101-110) Philadelphia. Elsevier.
- Proximal twitches are unfavorable and should not be accepted for injection. The transgluteal approach to the sciatic nerve should cover the sciatic nerve (obviously), including branches to the knee and ankle joints. The posterior cutaneous nerve of the thigh (PCNT) may be blocked by the transgluteal approach. The PCNT is a small nerve that innervates the skin on the posterior thigh. It initially runs beside the sciatic nerve but diverges as it travels distal. Thus, proximal blocks of the sciatic nerve are more likely than distal blocks to anesthetize the PCNT.
- A more distal approach to the sciatic nerve is the infragluteal sciatic nerve block. Palpate the greater trochanter (GT) and the ischial tuberosity (IT). Draw a line between them.
- Measure and mark the midpoint of this IT/GT line.
- Draw a perpendicular line 4 cm distal from the IT/GT line
- This point should be the needle insertion site for an infragluteal nerve block. This site should be 10 cm off midline, a distance that is well-conserved between adults, independent of BMI. Insert the needle perpendicular to the skin in all planes. A distal twitch should be sought.
- Above is the distribution of analgesia from infragluteal block.
- This is a projection of the path of the sciatic nerve and where it is blocked by the various approaches previously described.
- We move on to discussing blocks of the components of the lumbar plexus, starting with the femoral nerve and the relevant surface and muscular anatomy. The inguinal ligament connects the anterior superior iliac spine (ASIS) to the pubic tubercle (PT). The quadriceps muscles, a large component of the anterior compartment of the thigh, is composed of four muscles, all innervated by the femoral nerve. These muscles are the rectus femoris, and 3 vastus muscles: lateralis, intermedius, and medialis.
- Other muscles of the anterior thigh include the iliopsoas, pectineus, and the sartorius.
- The femoral nerve and vessels emerge from underneath the inguinal ligament, and are arrayed nerve, artery, and vein from lateral to medial. The mnemonic āNAVel to the navelā can help you remember how they are arranged.
- If performing a nerve stimulator-guided femoral block, palpate the femoral artery, and insert the needle perpendicular to the skin 1 cm lateral to the femoral pulse. The desired pattern of stimulation is quad contraction and patellar snap. Enneking F, Chan V, GREGER J, Hadzic A, LANG S, Horlocker T. Lower-extremity peripheral nerve blockade: Essentials of our current understanding. Reg Anesth Pain Med. 2005;30(1):4-35.
- For an ultrasound-guided femoral nerve block, center the ultrasound probe 1 cm lateral to the femoral pulse.
- This is a common ultrasound view of the femoral triangle.
- The femoral artery and iliopsoas muscle are indicated here.
- The superficial fascia, overlying femoral artery, nerve and iliopsoas is called the fascia lata. In contrast, the fascia iliaca runs diagonally along the iliopsoas, encasing the femoral nerve and running underneath the femoral artery.
- The flat, teardrop-shaped femoral nerve is seen here in cross section lateral to the femoral artery, encased by fascia iliaca.
- An in-plane approach to the femoral nerve with come in from superficial and lateral.
- The needle will first pierce the fascia lata then the fascia iliaca. An advantage of the in plane approach is the ability to come in from the side and avoid the nerve itself, piercing the fascia iliaca without passing intraneural. Injection immediately above or below the nerve is acceptable practice, though there is some suggestion that injection above the nerve may result in less motor weakness (cite). A catheter may also be placed. Injection into the sheath with the nerve instead above or below is also acceptable so long as no swelling of the nerve occurs (defined as any perceptible change in the area of the nerve tissue). Such swelling suggests an unacceptable intraneural injection.
- an out of plane approach will come in from above the nerve, crossing the fascia lata then carefully crossing the superficial aspect of the fascia iliaca, crossing fascia but carefully not going intraneural.
- In practice, only the needle tip is visible in the out of plane approach. This manifests as a bright spot with some acoustic shadowing when the tip passes under the needle. If the needle is advanced further beyond the first appearance of the needle, then it is no longer the tip that is visualized, but a portion of the shaft.
- For nerve stimulator-guided femoral block (with or without ultrasound), a quadriceps twitch, especially a patellar snap, should be sought. Sartorius twitch suggests a superficial or medial needle location, stimulating a separate branch of the femoral nerve. A sartorius twitch does not produce a patellar snap, and produces a contraction along the course of that muscle from ASIS toward the medial posterior knee. There is evidence that injecting with sartorius twitch produces good femoral blockade. Adduction twitch suggests stimulation of the pectineus, either by direct stimulation (needle too deep) or catching the anterior division of the femoral nerve. A successful femoral block should result in anesthesia of the anterior thigh and medial calf. A portion of the knee joint is innervated by the femoral nerve. Weakness in knee extension is expected and can contribute to falls. Anns JP, Chen EW, Nirkavan N, McCartney CJ, Awad IT. A Comparison of Sartorius Versus Quadriceps Stimulation for Femoral Nerve Block. Anesth Analg. 2011;112(3):725-731.
- The saphenous nerve is the distal continuation of the femoral nerve. Its purported advantage is that blockade occurs distal to where muscular branches of the femoral nerve to quad muscles diverge. This produces less motor weakness and hopefully less risk of fall. 1.Jaeger P, Nielsen ZJK, Henningsen MH, Hilsted KL, Mathiesen O, Dahl JB. Adductor canal block versus femoral nerve block and quadriceps strength: a randomized, double-blind, placebo-controlled, crossover study in healthy volunteers. Anesthesiology. 2013;118(2):409-415.
- A true femoral block only occurs within a small area in the groin along the course of the nerve before the femoral artery splits. A saphenous nerve block can occur anywhere in the thigh distal to the femoral artery split. A common place to perform a saphenous block is within the adductor canal, a small groove underneath the sartorius muscle and between vastus medialis and adductor muscles. This canal carries the femoral artery, vein, and saphenous nerve and runs in the middle third of the femur.
- This ultrasound image shows the adductor canal mid-way along the femur.
- The femoral artery and vein are seen here.
- Muscular distinctions are easy to see, with the boundaries of the adductor canal marked here. The sartorius muscle overlies superficially. The vastus medialis is, ironically, the medial boundary. The adductors are the deep and medial boundary of the adductor canal. At mid-femur, this may be the adductor longus, while in the distal third of the femur, the adductor magnus is deep to the sartorius. 1.Lund J, Jenstrup MT, Jaeger P, SĆørensen AM, Dahl JB. Continuous adductor-canal-blockade for adjuvant post-operative analgesia after major knee surgery: preliminary results. Acta Anaesthesiol Scand. 2010;55(1):14-19.
- The saphenous nerve is typically adjacent to the artery, on the superficial side. In the proximal thigh, the saphenous nerve is lateral to the artery (similar to the femoral artery lying lateral to the artery in the groin). At some point as it runs distal in the thigh, the saphenous nerve crosses to be medial to the artery. That happens at a variable location. As the saphenous nerve is small, it is not reliably visualized on ultrasound. In this image, it could be either lateral or medial to the artery.
- An in-plane needle approach often proceeds from lateral to medial. The goal is for the needle to gain access to the tissue plane beneath the sartorius muscle and adjacent to the femoral artery. Out of plane block is also acceptable. Catheter placement can occur here.
- The ideal peri-arterial spread, seen here, covers the superficial aspect of the artery, spreading and covering the saphenous nerve no matter on which side of the artery it is located.
- In the distal third of the thigh, the adductor canal terminates as the femoral artery and vein penetrate the adductor magnus and pass behind the femur into the posterior thigh to become the popliteal artery and vein.
- A small arterial branch can occationally be seen next to the continuation of the saphenous nerve in the distal thigh. This is the descending geniculate artery. Like the nerve, it lies beneath the sartorius muscle.
- A saphenous block can be performed distal to the termination of the adductor canal. Terminology regarding saphenous nerve blocks can be confusing, but this distal block could be correctly termed a saphenous block or a subsartorial block. However, is should not be called a periarterial block or an adductor canal block. Some evidence suggests this approach is less likely to produce saphenous anesthesia compared to an adductor canal block. 1.Marian AA, Ranganath Y, Bayman EO, Senasu J, Brennan TJ. A Comparison of 2 Ultrasound-Guided Approaches to the Saphenous Nerve Block. Reg Anesth Pain Med. 2015;40(5):623-630.
- At this level, no large artery or vein is seen. A small artery (the descending geniculate) might be seen on ultrasound scan, though it is not visible in this static image.
- The sartorius muscle is seen here. More lateral is still the vastus medialis. Deep to the sartorius is the adductor magnus.
- This hyperechoic structure might represent the saphenous nerve, though it is often small or indistinct. In plane needle approach typically proceeds from lateral to medial. Out of plane block is also acceptable. Catheter placement can occur here.
- Ideal spread here is a spreading of fascial layers deep to the sartorius muscle. The appearance is similar to a successful TAP block, rectus block, or pec block.
- Nerve stimulation for the saphenous nerve block has the disadvantage of not providing a reliable motor response, though a medial calf sensory paresthesia may result from stimulation. Multiple studies have used saphenous blocks with success for knee surgery. The amount of the anterior thigh anesthetized may depend on how distal the block location.
- The lateral femoral cutaneous nerve (LFCN) block is another sensory nerve that can be blocked.
- It emerges from underneath the inguinal ligament into the lateral thigh approximately 2 cm medial and 2 cm caudad to the ASIS, though there is significant variation. Brown, D.L. (2010). Lateral Femoral Cutaneous Block in 4th Ed. Atlas of Regional Anesthesia. (pp. 121-124) Philadelphia. Elsevier.
- Blockade at this level is usually done with a landmark technique by choosing a needle insertion site 2 cm medial and caudal to the ASIS, then injecting a weal of 5-10 mL local anesthetic subcutaneously in the area. Twitch could be used, but would only produce lateral thigh paresthesia.
- Use of ultrasound is described, and involves looking for the small LFCN just superficial to the sartorius muscle or, failing nerve identification, injection of local superficial to the sartorius muscle to spread to the likely nerve path. 5-10 mL of local is commonly used. 1.Ng I, Vaghadia H, Choi PT, Helmy N. Ultrasound Imaging Accurately Identifies the Lateral Femoral Cutaneous Nerve. Anesth Analg. 2008;107(3):1070-1074.
- The LFCN is a sensory nerve which innervates the lateral thigh. Its innervation is variable, and numbness of the distal, anterior thigh has been describe in a subset of patients. Corujo A, Franco CD, Williams JM. The Sensory Territory of the Lateral Cutaneous Nerve of the Thigh as Determined by Anatomic Dissections and Ultrasound-Guided Blocks. Reg Anesth Pain Med. 2012;37(5):561-564.
- The obturator is our next block to be discussed. The previously described anatomy of the groin and inguinal region is relevant, but omitted characterization of the high medial thigh anatomy, which will be covered here.
- Stripping away the vascular structures, we have the pectineus and iliopsoas in the anterior thigh that have already been discussed. The deepest muscle of the medial thigh is the adductor magnus, which runs the length of the femur in the deep medial thigh.
- Superficial to the adductor magnus in the proximal, medial thigh is the adductor brevis, connecting the pubis and femur.
- A third muscle layer lies superficial to the adductor brevis; that is the adductor longus. It runs from the pubis to the femur, but is broader than the adductor brevis.
- These 3 adductors create an āadductor sandwichā through which branches of the obturator nerve run. The obturator is a small nerve with a variable number of branches that innervate a large number of structures. The number of branches can vary substantially, but as it emerges from the medial pelvis through the obturator canal, branch or branches run to the a portion of the hip joint. An anterior branch of the obturator nerve runs between the Adductor brevis and longus, while a posterior branch runs between the Adductor longus and magnus. The adductors, as well as the gracillis and obturator externus are innervated by these branches. The posterior branch of the obturator nerve innervates a portion of the knee joint. Anagnostopoulou S, Kostopanagiotou G, Paraskeuopoulos T, Chantzi C, Lolis E, Saranteas T. Anatomic Variations of the Obturator Nerve in the Inguinal Region. Reg Anesth Pain Med. 2009;34(1):33-39. Taha AM. Ultrasound-Guided Obturator Nerve Block. Anesth Analg. 2012;114(1):236-239. Birnbaum K, Prescher A, Hessler S, Heller KD. The sensory innervation of the hip joint--an anatomical study. Surg Radiol Anat. 1997;19(6):371-375.
- The anterior and posterior branches of the obturator are sought using ultrasound and/or nerve stimulation. With ultrasound, the pectineus muscle is traced medial in the groin until the three adductors (longus, brevis, magnus) are in view, then a needle is placed between longus and brevis and also between brevis and magnus. 5 mL of local anesthetic is injected at each point. Nerve stimulation seeking a medial thigh (adduction) twitch is sought. Weakness of the thigh adductors signifies blocks success and may place the patient at risk for falls, so caution is advised, similar to with a femoral block. The sensory innervation of the obturator block is highly variable. One study of obturator blocks found no site of skin anesthesia or hypoesthesia, that is no skin numbness at all, in approximately half of patients. That means that the area of medial thigh, considered to be innervated by the obturator, is instead innervated by another nerve, such as the femoral nerve, is half of cases. Thus, skin anesthesia is an unreliable test for obturator block effect, and motor weakness should be used instead. This variability of skin innervation may be why the obturator is described as commonly blocked in a fascia iliaca block ā it might not be. The femoral nerve might just be covering that area of skin in the medial thigh. Bouaziz H, Vial F, Jochum D, et al. An evaluation of the cutaneous distribution after obturator nerve block. Anesth Analg. 2002;94(2):445-449.
- Another block performed from the anterior thigh is a block of the sciatic nerve, done from a supine position, called the anterior sciatic block. Seen here is a projection of the femur onto the surface of the thigh for reference. The greater and lesser trochanter are bony protuberances of the femur.
- The pubic tubercle is the palpable lateral aspect of the pubis and is used as a landmark for the anterior sciatic block.
- Seen here is a projection of the sciatic nerve onto the thigh, showing its typical course.
- Put together, projections of the femur and sciatic nerve show the nerveās location deep to the femur, with a portion of the nerve slightly medial to the femur in the proximal thigh, where the anterior sciatic block is performed.
- To determine the needle insertion site by the Beck approach, first draw a line from ASIS to pubic tubercle (PT). Wiegel M, Reske A, Hennebach R, et al. Anterior sciatic nerve block - new landmarks and clinical experience. Acta Anaesthesiol Scand. 2005;49(4):552-557. Vloka JD, Hadzic A, April E, Thys DM. Anterior approach to the sciatic nerve block: the effects of leg rotation. Anesth Analg. 2001;92(2):460-462.
- Then, divide that line in thirds.
- Draw a perpendicular to the ASIS/PT line from the medial third hash mark on that line.
- Draw a line paralleling the ASIS/PT line through the greater trochanter.
- Where the line through the GT intersects the perpendicular off the ASIS/PT line is the needle insertion site.
- An alternative set of landmarks is the Chelly approach. In it, a line is drawn initially from ASIS to the angle of the pubic symphysis (PS), a structure more medial than the pubic tubercle. This line is divided in half, and a perpendicular is drawn distal from the midpoint 8 cm. That is where the needle is placed. Both blocks are, on average, quite deep: 10.5 cm in Chellyās study. A 15 cm needle should be used. When the needle is placed, perpendicularly to the skin, it should be advanced and nerve stimulation used to seek a distal sciatic twitch ā foot dorsiflexion or plantar flexion. If bone is contacted, it may be the lesser trochanter. Medial rotation of the femur may move the lesser trochanter out of the way, allowing passage of the needle to the nerve. Alternatively, slight caudal angulation of the needle may allow passage past the trochanter. The sciatic nerve should lie 3-4 cm beyond the depth where needle contacted femur. Chelly JE, Delaunay L. A new anterior approach to the sciatic nerve block. Anesthesiology. 1999;91(6):1655-1660.
- Femoral nerve stimulation is common during block placement at superficial depths, since the needle goes past the femoral nerve on its trajectory. Gluteal stimulation implies the needle tip is too deep. The pattern of anesthesia is similar to other approaches to the sciatic nerve, with possible anesthesia of the nearby posterior cutaneous nerve of the thigh, and joint analgesia for portions of the knee and ankle.
- Blockade of the sciatic nerve distal in the posterior thigh, near its split into tibial and common peroneal branches is called a popliteal block. More accurately, it could be referred to as a popliteal approach to the sciatic nerve or a popliteal sciatic nerve block, to prevent confusion about which nerve is blocked. This block can be performed with the patient in any number of positions, from prone, to lateral decubitus, to Simās position, to supine with the leg elevated and supported. For this lecture, we will assume a prone position for nerve stimulator-guided block. For ultrasound-guided block, assume supine with leg elevated and supported. Those decisions reflect preferences, nothing more. Start by noting the popliteal crease at the bend of the knee.
- Five muscles make up the semi-diamond-shaped popliteal fossa. In the thigh, the deepest (most ventral) muscles of the posterior thigh are the semimembranosus (which runs from ischial tuberosity to the medial tibia) and the short head of the biceps femoris (which runs from the posterior femur to the lateral condyle of the femur)
- Superficial (dorsal) to the semimebranosus and short head of the biceps on the back of the thigh are the semitendinosus and long head of the biceps, respectively. Below the knee are the heads of the gastrocnemius or āgastroc.ā
- Together, these muscles form the diamond-shaped popliteal fossa. Brown, D.L. (2010). Popliteal and Saphenous Block in 4th Ed. Atlas of Regional Anesthesia. (pp. 129-134) Philadelphia. Elsevier
- For nerve stimulator-guided popliteal sciatic nerve block, the tendons of the biceps femoris and semitendinosus are palpated, the popliteal crease is marked, and a point 7 cm proximal and 1 cm lateral to the midpoint of the popliteal crease is marked. The needle is placed at this site and advanced perpendicular in all planes to the skin. A sciatic twitch is sought, with either tibial stimulation (foot plantar flexion or inversion) or peroneal stimulation (foot dorsiflexion or eversion) acceptable.
- Ultrasound guidance, with or without nerve stimulation is frequently used. The ultrasound probe is positioned the same approximately 7 cm above the popliteal crease, slightly lateral to mid thigh.
- Here is a projection of the popliteal vessels which as previously discussed, leave the adductor canal and enter the posterior thigh through the adductor magnus near the distal third of the thigh. The sciatic nerve, with its branch into Common peroneal and tibial nerves is also projected here. On average, the sciatic nerve splits ~ 6 cm proximal to the popliteal crease. That is the reason for being 7 cm proximal for a nerve stimulator-guided block. In practice, the sciatic nerve split is quite variable.
- The split of the sciatic nerve is a useful ultrasound marker of the sciatic nerve, allowing identification of the nerve and its branches.
- When performing an ultrasound-guided popliteal sciatic nerve block, the principle of anisotropy or angle dependence of visualized structures on ultrasound is important. Nerves show up brightest and most distinct when the probe is angled perpendicular to the path of the needle. This is often not the same as being perpendicular to the skin, as seen in this image. The sciatic nerve as it travels distal in the thigh goes from deep to superficial (dorsal).
- A slight tilt of the probe distal, steering the beam distal, relative to the plane of the skin will improve nerve visualization compared to an ultrasound probe perpendicular to the skin.
- In a supine approach to the popliteal sciatic block, the leg is elevated with calf and ankle supported on a padded table or bespoke leg holder. The knee is slightly bent. The vastus lateralis and biceps femoris can often be palpated.
- A slight indention is often felt between the two muscles and this can serve as a useful needle insertion site.
- This is a representative ultrasound image of the popliteal fossa. It is flipped, with superficial side (nearest the probe) on the bottom because this block was performed supine with leg raised.
- Muscles are visible on either side of the popliteal fossa, which contains a large amount of fat. The biceps femoris is lateral, the semimembranosus is medial. The semitendinosus has collapsed to a tendon at this level in the thigh and is off screen medially.
- The peanut-shaped hyperechoic structure is the sciatic nerve as it splits
- The common peroneal branch emerges from the lateral aspect of the nerve and tends to run superficial and lateral (dorsal) as it separates. The tibial nerve continues distal in a relatively straight path.
- The needle approach in the supine position comes from the deep and lateral side of the screen as the needle is placed between the vastus lateralis and biceps femoris. This angle allows the needle to pass between the two components of the sciatic nerve as it splits. Passing between the two nerves allows a block in the sub-epineureal space which speeds block onset and success. Since the nerve fibers have already separated, the needle may pass between and minimize risk of fascicular injury and intrafascicular injection. Perlas A, Wong P, Abdallah F, Hazrati L-N, Tse C, Chan V. Ultrasound-Guided Popliteal Block Through a Common Paraneural Sheath Versus Conventional Injection. Reg Anesth Pain Med. 2013;38(3):218-225.
- Distal twitches are favorable when nerve stimulation is sought. Weakness of foot movement should be achieved with successful block, and the shaded area anesthetized. Articular fibers off the tibial nerve run to the posterior capsule of the knee and can be blocked even by relatively distal popliteal approaches. The ankle joint is anesthetized as well.
- The final block to discuss is the ankle block. CCA-SA 3
- Seen here are medial and lateral views of the foot. The ankle block is actually a block of 5 separate nerves: 2 deep nerves, and 3 superficial ones. 4 of these nerves are branches of the sciatic nerve. The 5 nerves are the 1) superficial peroneal and the 2) deep peroneal (from the common peroneal), the 3) saphenous (from the femoral), the 4) posterior tibial (from the tibial), and finally the 5) sural (from branches of both the common peroneal and tibial). CCA-SA 3
- The superficial 3 nerves are seen here, one on the medial side, 2 on the lateral aspect CCA-SA 3
- The superficial nerves are the superficial peroneal, sural, and saphenous. CCA-SA 3
- These nerves can be anesthetized by injecting a weal of local anesthetic subcutaneously from the anterior surface of the ankle or distal calf at a level just above the medial or lateral malleolus. This is often done with a 25 g needle and 10 mL syringes of local anesthetic. If you start from the anterior aspect, you can inject along the medial aspect, then use the initial insertion site to inject the lateral aspect. CCA-SA 3
- A good subcutaneous injection will block all three nerves. CCA-SA 3
- The deep nerves are the posterior tibial, and the deep peroneal. CCA-SA 3
- On the medial ankle behind the medial malleolus, 2 tendons may be palpable: the flexor digitorum longus tendon and tibialis posterior tendon. CCA-SA 3
- Posterior to those tendons, the posterior tibial (PT) artery may be palpable. CCA-SA 3
- Pick a needle insertion site just posterior to the PT pulse, insert the needle at that site until bone is contacted, then withdraw the needle slightly and inject 5 mL after negative aspiration. This should anesthetize the sole of the foot. CCA-SA 3
- Ultrasound can be used for this block and a periarterial injection is sought if the nerve is not easily visualized. Chin KJ, Wong NWY, Macfarlane AJR, Chan VWS. Ultrasound-guided versus anatomic landmark-guided ankle blocks: a 6-year retrospective review. Reg Anesth Pain Med. 2011;36(6):611-618. CCA-SA 3
- Here is the dorsum of the foot. Public Domain
- Two prominent tendons are often palpable, the extensor digitorum longus laterally and the extensor hallusis longus medially. Together, they extend the toes Public Domain
- Between these two tendons, the dorsalis pedis artery should be palpable. Public Domain
- Needle insertion may occur just lateral to the pulse. The needle should be inserted to bone, withdrawn slightly, and 5 mL local anesthetic injected following negative aspiration. This should anesthetize the web space between the first and second toe. Public Domain
- Ultrasound can be used for this block. A periarterial injection lateral to the dorsalis pedis artery is sought if the small deep peroneal nerve cannot be visualized. Public Domain Chin KJ, Wong NWY, Macfarlane AJR, Chan VWS. Ultrasound-guided versus anatomic landmark-guided ankle blocks: a 6-year retrospective review. Reg Anesth Pain Med. 2011;36(6):611-618.
- The combination of these 5 nerve blocks leads to complete sensory anesthesia of the foot, but will not produce as much motor weakness as more proximal blocks, Since the muscles that move the ankle joint are spared. This can be a benefit by decreasing post-op fall risk, or a hindrance if the patient is moving her/his foot intraoperatively.
- Here are the areas anesthetized by each individual component of the ankle block. Posterior tibial nerve covers the sole of the foot. Deep peroneal nerve covers the web space between the 1st and 2nd toe. Superficial peroneal covers the dorsum (top) of the foot. Sural covers the lateral aspect of the ankle Saphenous covers the medial part of the ankle and may send branches to the medial malleolus and ankle Many of these typically landmark-based blocks have been investigated as ultrasound guided blocks with some success. 1.LĆ³pez AM, Sala-Blanch X, Magaldi M, Poggio D, Asuncion J, Franco CD. Ultrasound-Guided Ankle Block for Forefoot Surgery. Reg Anesth Pain Med. 2012;37(5):554-557. 2.Chin KJ, Wong NWY, Macfarlane AJR, Chan VWS. Ultrasound-guided versus anatomic landmark-guided ankle blocks: a 6-year retrospective review. Reg Anesth Pain Med. 2011;36(6):611-618. 3.Redborg KE, Sites BD, Chinn CD, et al. Ultrasound Improves the Success Rate of a Sural Nerve Block at the Ankle. Reg Anesth Pain Med. 2009;34(1):24-28.
- In review, we have covered one or more methods to block each of the nerves listed here. This was not meant to be an exhaustive lecture, though it may be exhausting.
- These diagrams show the expected areas anesthetized by various approaches to nerves derived from the lumbar plexus. Keep in mind that anatomic variation, including variation in innervation, is the norm, not an exception. Variance from these patterns is common.
- These diagrams show the variation in different approaches to the sciatic nerve or lumbosacral plexus. The main variation is in the likelihood of blocking the posterior cutaneous nerve of the thigh (PCNT). Keep in mind that this nerve only anesthetizes the skin on the back of the thigh. Whether the PCNT is blocked carries very little significance to almost any surgery ā it is likely of trivial importance.
- The lateral femoral cutaneous nerve is a superficial nerve that innervates a portion of the skin of the lateral thigh. It has no articular branches. The obturator sends variable branches to the hip and knee joints. The saphenous nerve, a continuation of the femoral nerve sends articular branches to the knee. The sciatic nerve sends branches to the hip and knee joint. Ref: Enneking F, Chan V, Greger J, Hadzic A, Lang S, Horlocker T. Lower-extremity peripheral nerve blockade: Essentials of our current understanding. Reg Anesth Pain Med. 2005;30(1):4-35. Ref: Birnbaum K, Prescher A, Hessler S, Heller KD. The sensory innervation of the hip joint--an anatomical study. Surg Radiol Anat. 1997;19(6):371-375. The ankle block anesthetizes 5 nerves: sural, deep peroneal, superficial peroneal, posterior tibal, and saphenous. Only the saphenous derives from the femoral nerve. The others have a sciatic origin. Ref: Enneking F, Chan V, Greger J, Hadzic A, Lang S, Horlocker T. Lower-extremity peripheral nerve blockade: Essentials of our current understanding. Reg Anesth Pain Med. 2005;30(1):4-35.
- 3. The parasacral block is performed at the point where the lumbosacral plexus exits the pelvis. At this proximal location, the sciatic nerve is blocked before any non-neuraxial approach to the sciatic nerve. Other high sciatic blocks, such as an anterior sciatic or transgluteal sciatic are slightly distal to the parasacral block. The popliteal block is significantly distal nearer the knee. Ref: Ripart J, Cuvillon P, Nouvellon E, Gaertner E, Eledjam J. Parasacral approach to block the sciatic nerve: A 400-case survey. Reg Anesth Pain Med. 2005;30(2):193-197. 4. The adductor canal runs deep to the sartorius muscle, is bounded laterally by the vastus medialis, and deep and posterior to the canal is the adductor group ā including the adductor longus and adductor magnus. The rectus femoris is more anterior and does not adjoin the adductor canal. Ref: Lund J, Jenstrup MT, Jaeger P, SĆørensen AM, Dahl JB. Continuous adductor-canal-blockade for adjuvant post-operative analgesia after major knee surgery: preliminary results. Acta Anaesthesiol Scand. 2010;55(1):14-19.
- LE Lecture References by Slide Ā Slide 3 Clinical Anesthesia 7th Edn. P. G. Barash, B. F. Cullen and R. K. Stoelting (editors). Published by Lippincott, Williams and Wilkins, Philadelphia, USA. 2013 Ā Slide 7 & 39 Enneking F, Chan V, GREGER J, Hadzic A, LANG S, Horlocker T. Lower-extremity peripheral nerve blockade: Essentials of our current understanding. Reg Anesth Pain Med. 2005;30(1):4-35. Ā Slide 10 Capdevila X, Macaire P, Dadure C, et al. Continuous psoas compartment block for postoperative analgesia after total hip arthroplasty: new landmarks, technical guidelines, and clinical evaluation. Anesth Analg. 2002;94(6):1606-1613. Ā Slide 14 Heller AR, Fuchs A, Rƶssel T, et al. Precision of traditional approaches for lumbar plexus block: impact and management of interindividual anatomic variability. Anesthesiology. 2009;111(3):525-532. Ā Slide 15 Ilfeld BM, Loland VJ, Mariano ER. Prepuncture Ultrasound Imaging to Predict Transverse Process and Lumbar Plexus Depth for Psoas Compartment Block and Perineural Catheter Insertion. Anesth Analg. 2010;110(6):1725-1728. Ā Slide 16 Gadsden JC, Lindenmuth DM, Hadzic A, Xu D, Somasundarum L, Flisinski KA. Lumbar plexus block using high-pressure injection leads to contralateral and epidural spread. Anesthesiology. 2008;109(4):683-688. Ā Slide 21 Ripart J, Cuvillon P, Nouvellon E, Gaertner E, Eledjam J. Parasacral approach to block the sciatic nerve: A 400-case survey. Reg Anesth Pain Med. 2005;30(2):193-197. Ā Slide 21 OŹ¼Connor M, Coleman M, Wallis F, Harmon D. An Anatomical Study of the Parasacral Block Using Magnetic Resonance Imaging of Healthy Volunteers. Anesth Analg. 2009;108(5):1708-1712. Ā Slide 28 Brown, D.L. (2010). Sciatic Block in 4th Ed. Atlas of Regional Anesthesia. (pp. 101-110) Philadelphia. Elsevier. Ā Slide 7 & 39 Enneking F, Chan V, GREGER J, Hadzic A, LANG S, Horlocker T. Lower-extremity peripheral nerve blockade: Essentials of our current understanding. Reg Anesth Pain Med. 2005;30(1):4-35. Ā Slide 49 Anns JP, Chen EW, Nirkavan N, McCartney CJ, Awad IT. A Comparison of Sartorius Versus Quadriceps Stimulation for Femoral Nerve Block. Anesth Analg. 2011;112(3):725-731. Ā Slide 50 Jaeger P, Nielsen ZJK, Henningsen MH, Hilsted KL, Mathiesen O, Dahl JB. Adductor canal block versus femoral nerve block and quadriceps strength: a randomized, double-blind, placebo-controlled, crossover study in healthy volunteers. Anesthesiology. 2013;118(2):409-415. Ā Slide 54 Lund J, Jenstrup MT, Jaeger P, SĆørensen AM, Dahl JB. Continuous adductor-canal-blockade for adjuvant post-operative analgesia after major knee surgery: preliminary results. Acta Anaesthesiol Scand. 2010;55(1):14-19. Ā Slide 60 Marian AA, Ranganath Y, Bayman EO, Senasu J, Brennan TJ. A Comparison of 2 Ultrasound-Guided Approaches to the Saphenous Nerve Block. Reg Anesth Pain Med. 2015;40(5):623-630. Ā Slide 67 Brown, D.L. (2010). Lateral Femoral Cutaneous Block in 4th Ed. Atlas of Regional Anesthesia. (pp. 121-124) Philadelphia. Elsevier. Ā Slide 69 Ng I, Vaghadia H, Choi PT, Helmy N. Ultrasound Imaging Accurately Identifies the Lateral Femoral Cutaneous Nerve. Anesth Analg. 2008;107(3):1070-1074. Ā Slide 70 Corujo A, Franco CD, Williams JM. The Sensory Territory of the Lateral Cutaneous Nerve of the Thigh as Determined by Anatomic Dissections and Ultrasound-Guided Blocks. Reg Anesth Pain Med. 2012;37(5):561-564. Ā Slide 75 Anagnostopoulou S, Kostopanagiotou G, Paraskeuopoulos T, Chantzi C, Lolis E, Saranteas T. Anatomic Variations of the Obturator Nerve in the Inguinal Region. Reg Anesth Pain Med. 2009;34(1):33-39. Ā Slide 75 Taha AM. Ultrasound-Guided Obturator Nerve Block. Anesth Analg. 2012;114(1):236-239. Ā Slide 75 Birnbaum K, Prescher A, Hessler S, Heller KD. The sensory innervation of the hip joint--an anatomical study. Surg Radiol Anat. 1997;19(6):371-375. Ā Slide 76 Bouaziz H, Vial F, Jochum D, et al. An evaluation of the cutaneous distribution after obturator nerve block. Anesth Analg. 2002;94(2):445-449. Ā Slide 81 Wiegel M, Reske A, Hennebach R, et al. Anterior sciatic nerve block - new landmarks and clinical experience. Acta Anaesthesiol Scand. 2005;49(4):552-557. Ā Slide 81 Vloka JD, Hadzic A, April E, Thys DM. Anterior approach to the sciatic nerve block: the effects of leg rotation. Anesth Analg. 2001;92(2):460-462. Ā Slide 86 Chelly JE, Delaunay L. A new anterior approach to the sciatic nerve block. Anesthesiology. 1999;91(6):1655-1660. Ā Slide 91 Brown, D.L. (2010). Popliteal and Saphenous Block in 4th Ed. Atlas of Regional Anesthesia. (pp. 129-134) Philadelphia. Elsevier Ā Slide 104 Perlas A, Wong P, Abdallah F, Hazrati L-N, Tse C, Chan V. Ultrasound-Guided Popliteal Block Through a Common Paraneural Sheath Versus Conventional Injection. Reg Anesth Pain Med. 2013;38(3):218-225. Ā Slide 107 Brown, D.L. (2010). Ankle Block in 4th Ed. Atlas of Regional Anesthesia. (pp. 135-140) Philadelphia. Elsevier Ā Slide 116 & 121 Chin KJ, Wong NWY, Macfarlane AJR, Chan VWS. Ultrasound-guided versus anatomic landmark-guided ankle blocks: a 6-year retrospective review. Reg Anesth Pain Med. 2011;36(6):611-618. Ā Slide 123 LĆ³pez AM, Sala-Blanch X, Magaldi M, Poggio D, Asuncion J, Franco CD. Ultrasound-Guided Ankle Block for Forefoot Surgery. Reg Anesth Pain Med. 2012;37(5):554-557. Ā Slide 123 Redborg KE, Sites BD, Chinn CD, et al. Ultrasound Improves the Success Rate of a Sural Nerve Block at the Ankle. Reg Anesth Pain Med. 2009;34(1):24-28.