© Advanced nerve blocks - Dr Anand Sardesai - Cambridge; United Kingdom
Ankle block
Ankle Block
Nerve Supply of the Ankle
The ankle joint and foot receive sensory innervation from five nerves: • Four branches of the sciatic nerve • One branch of the femoral nerve Nerve Origin Area Supplied Any blood vessel nearby? Tibial Sciatic Plantar foot, heel Posterior tibial artery and often two veins Deep peroneal Common peroneal (Sciatic) First web space Dorsalis pedis artery Superficial peroneal Common peroneal (Sciatic) Dorsum of foot No Sural Tibial + common peroneal (Sciatic) Lateral foot, heel Short Saphenous Vein Saphenous Femoral Medial ankle Great Saphenous Vein Note: 1. There is significant overlap between nerve territories. 2. Four of these nerves lie next to blood vessel. If you can find the blood vessel, it is often easy to find the nerve next to it. ________________________________________ Individual Nerves – Key Anatomy Tibial Nerve – Anatomy Origin • Terminal branch of the sciatic nerve • Roots: L4–S3 • Arises at the upper angle of the popliteal fossa ________________________________________ Course 1. Popliteal Fossa • Descends vertically through the midline • Lies: o Posterior (superficial) to popliteal vein and artery • Most superficial structure when scanning from behind • Gives off: o Muscular branches to gastrocnemius, soleus, plantaris o Medial sural cutaneous nerve (contributes to sural nerve) ________________________________________ 2. Leg (Posterior Compartment) • Passes deep to the tendinous arch of soleus • Travels in the deep posterior compartment • Closely accompanied by the posterior tibial artery and veins • Lies: o Initially medial to the vessels o Then posterior to them distally • Supplies: o Tibialis posterior o Flexor digitorum longus o Flexor hallucis longus ________________________________________ 3. At the Ankle (Tarsal Tunnel) • Passes deep to the flexor retinaculum • Runs posterior to the medial malleolus • Arrangement from anterior → posterior (Tom, Dick, And Very Nervous Harry): 1. Tibialis posterior tendon 2. Flexor digitorum longus tendon 3. Posterior tibial artery 4. Posterior tibial vein 5. Tibial nerve 6. Flexor hallucis longus tendon • The tibial nerve lies: o Between posterior tibial vessels and FHL tendon ________________________________________ Terminal Branches At or just distal to the flexor retinaculum, the tibial nerve divides into: • Medial plantar nerve • Lateral plantar nerve These supply: • Sensory innervation to the sole of the foot • Motor innervation to intrinsic foot muscles ________________________________________ Sensory Distribution • Heel (via medial calcaneal branches) • Entire plantar surface of the foot • Posterior sole ________________________________________ Motor Function • Plantar flexion • Toe flexion • Inversion of the foot • Only ankle-level nerve that produces a motor response on stimulation → plantar flexion of toes ________________________________________ 2. Common Peroneal (Fibular) Nerve • Terminal branch of sciatic nerve • Runs along medial border of biceps femoris • Passes over lateral head of gastrocnemius • Winds around neck of fibula • Divides into: o Deep peroneal nerve o Superficial peroneal nerve ________________________________________ 3. Deep Peroneal Nerve • Begins deep to peroneus longus • Passes under extensor digitorum longus • Lies anterior to interosseous membrane • Runs with anterior tibial artery (Dorsalis Pedis Artery) • Located between: o Tibialis anterior o Extensor hallucis longus • Supplies first dorsal web space ________________________________________ 4. Superficial Peroneal Nerve • Lies between peroneus longus and fibula • Supplies: o Peroneus longus o Peroneus brevis • Pierces deep fascia in lower third of leg • Becomes subcutaneous • Supplies: o Distal anterolateral leg o Most of dorsum of foot o Most toes ________________________________________ 5. Sural Nerve • Formed by: o Medial sural cutaneous nerve (tibial) o Sural communicating branch (common peroneal) • Lies with short saphenous vein • Passes behind lateral malleolus • Supplies: o Posterolateral lower leg o Lateral foot o Heel o Posterior sole ________________________________________ 6. Saphenous Nerve • Only femoral nerve contribution below knee • Arises in femoral triangle • Travels in adductor canal • Emerges between sartorius and gracilis • Becomes subcutaneous at medial knee • Travels with great saphenous vein • Supplies medial ankle and foot ________________________________________ Indications of Ankle block • Surgery below ankle joint o Forefoot o Midfoot • Can be used with ankle tourniquet • Allows immediate mobilisation • Safe for bilateral blocks • Analgesia lasts 18–24 hours ________________________________________ Contraindications 1. Patient refusal 2. Infection at injection sites ________________________________________ Key Practical Points 1. Not all five nerves must be blocked – tailor to surgical site 2. Confirm nerves by tracking proximally and distally on ultrasound 3. 4 of 5 nerves lie close to blood vessels 4. Scan cephalad to ankle joint – scanning at ankle is difficult due to probe contact issues 5. Multiple injections → sedation improves comfort ________________________________________ Ultrasound-Guided Ankle Block Preparation Patient • Supine position • Position of patient’s leg varies depending on which nerve is being blocked. o Leg placed over the nonoperative leg, foot slightly externally rotated, knee flexed- figure of four (for saphenous/tibial nerve). o Knee flexed and leg in neutral position (Deep peroneal). o Knee flexed and slightly internally rotated with foot resting on the bed (Sural nerve). o Leg on the bed slightly internally rotated (superficial peroneal nerve) • Light sedation may be helpful as multiple injections are needed • If the block is done for postoperative pain relief, then we perform the block under general anaesthesia General Ultrasound Principles • Scan cephalad to the ankle joint o at the level of the medial malleolus, achieving good probe–skin contact is difficult due to the concave contour between the medial malleolus and the heel. o Slightly more subcutaneous tissues- needle less likely to contact bone/periosteum- leading to less pain. • Identify nerves by: o Relation to blood vessels (four out of five nerves are close to blood vessels) o Tracking proximally and distally • Use in-plane needle approach if possible (not possible for deep peroneal nerve) • Aspirate frequently Equipment • High-frequency ultrasound probe + cover + gel • 50 mm insulated stimulating needle o Tibial nerve stimulation → plantar flexion • 23G hypodermic needle (other nerves) or use the 50 mm insulated needle • Local anaesthetic: o 0.5% levobupivacaine o ~5 mL per nerve • 2% chlorhexidine ________________________________________ Individual Nerve Blocks ________________________________________ 1. Tibial Nerve Block (Most Important) Position • Probe placed transversely just above the medial malleolus Ultrasound Anatomy • Posterior tibial artery (pulsatile, anechoic) • Posterior tibial veins — these are usually present as two venae comitantes on either side of the posterior tibial artery. Their position should be identified initially; however, during scanning the pressure applied with the probe to visualise the tibial nerve often compresses the veins, making them difficult or impossible to see. • Tibial nerve: o Hyperechoic o Lies posterior or posterolateral to artery o Between vessels and flexor hallucis longus tendon Technique 1. Identify posterior tibial artery using colour Doppler 2. Locate tibial nerve adjacent to it 3. Insert needle in-plane from posterior side 4. Advance toward nerve 5. Optional nerve stimulation → toe plantar flexion 6. Inject 5 mL LA to surround nerve ________________________________________ 2. Deep Peroneal Nerve Block Position • Probe placed transversely on anterior ankle, just above ankle joint Ultrasound Anatomy • Anterior tibial artery (Dorsalis pedis artery) • Deep peroneal nerve: o Small hyperechoic structure o The deep peroneal nerve has a variable position and may lie medial or lateral to the anterior tibial artery, depending on the level and orientation of the ultrasound scan. o Between tibialis anterior and extensor hallucis longus Technique 1. Identify anterior tibial artery 2. Locate nerve lateral to artery 3. Difficult to insert needle in-plane and out of plane insertion may be necessary. 4. Deposit 3–5 mL LA around nerve ________________________________________ 3. Superficial Peroneal Nerve Block Position • Probe placed on anterolateral lower leg, cephalad to the ankle joint. Ultrasound Anatomy Place the probe on the anterolateral aspect of the lower leg, cephalad to the ankle joint. Identify the acoustic shadow of the fibula. On either side of this shadow, the peroneal muscles and the extensor digitorum longus muscle can be seen. As the probe is moved proximally, the fibular shadow becomes deeper and the peroneal muscles and extensor digitorum longus move closer together. At this level, the superficial peroneal nerve is visualised superficial to the fascia. With further proximal movement of the probe, the nerve can be seen piercing the fascia and then lying deeper between the peroneal muscles and extensor digitorum longus. Technique 1. Identify nerve in superficial to the fascia 2. Use shallow in-plane approach 3. Inject 3–5 mL LA subcutaneously around nerve ________________________________________ 4. Sural Nerve Block Position • Probe placed posterolateral to ankle, above lateral malleolus Ultrasound Anatomy Place the probe over the Achilles tendon just cephalad to the lateral malleolus. Identify the short saphenous vein. Sural nerve is seen as a hyperechoic nerve lying adjacent to vein. Technique 1. Identify small saphenous vein 2. Locate sural nerve next to it 3. Insert needle in-plane 4. Inject 3–5 mL LA around nerve ________________________________________ 5. Saphenous Nerve Block Position • Probe placed on the medial side of the leg at midleg level Ultrasound Anatomy Identify Great saphenous vein. Usually either a single nerve or branches are seen next to vein. It is small, hyperechoic. Technique Identify great saphenous vein, locate nerve next to vein, inject 3–5 mL local anaesthetic superficially, creating a broad subcutaneous spread around the nerve. Eu sed eIn minim cupidatat non officia
Excepteur do u voluptate sunt labore.Do ea amet enim in officia
Dolor qui ex in magna amet offideserunt occaecat quis ea excepteur veniam.Nulla officia pariatur elit
Dolor ea in adipisicing consequat eiusmod in non dolor anim. Dolore velit minim culpa ullamco elit ipsum veniam esse, deserunt in aute, commodo in et laboris anim sed. Amet, cillum nulla esse laboris nisi pariatur dolor, excepteur occaecat id in ad pariatur occaecat nulla. Ut quis consequat ad fugiat amet, et magna. Sit adipisicing, incididunt quis ut nulla culpa ut enim magna qui aute non? Aliqua est proident lorem, sed nostrud aliquip tempor et cupidatat dolore voluptate non sint duis in. Cupidatat, minim sit ex magna ipsum non in, voluptate excepteur nulla minim sint dolore magna sint? Adipisicing do minim dolore ut aliqua id non officia, sed pariatur sed ipsum, in deserunt aute sunt ipsum. Cillum culpa duis aliqua. Est in id culpa qui do, occaecat enim do sunt incididunt. Voluptate ut do incididunt ut ea consectetur ipsum in.
© Advanced Nerve Blocks
Ankle block
Ankle Block
Nerve Supply of the Ankle
The ankle joint and foot receive sensory innervation from five nerves: • Four branches of the sciatic nerve • One branch of the femoral nerve Nerve Origin Area Supplied Any blood vessel nearby? Tibial Sciatic Plantar foot, heel Posterior tibial artery and often two veins Deep peroneal Common peroneal (Sciatic) First web space Dorsalis pedis artery Superficial peroneal Common peroneal (Sciatic) Dorsum of foot No Sural Tibial + common peroneal (Sciatic) Lateral foot, heel Short Saphenous Vein Saphenous Femoral Medial ankle Great Saphenous Vein Note: 1. There is significant overlap between nerve territories. 2. Four of these nerves lie next to blood vessel. If you can find the blood vessel, it is often easy to find the nerve next to it. ________________________________________ Individual Nerves – Key Anatomy Tibial Nerve – Anatomy Origin • Terminal branch of the sciatic nerve • Roots: L4–S3 • Arises at the upper angle of the popliteal fossa ________________________________________ Course 1. Popliteal Fossa • Descends vertically through the midline • Lies: o Posterior (superficial) to popliteal vein and artery • Most superficial structure when scanning from behind • Gives off: o Muscular branches to gastrocnemius, soleus, plantaris o Medial sural cutaneous nerve (contributes to sural nerve) ________________________________________ 2. Leg (Posterior Compartment) • Passes deep to the tendinous arch of soleus • Travels in the deep posterior compartment • Closely accompanied by the posterior tibial artery and veins • Lies: o Initially medial to the vessels o Then posterior to them distally • Supplies: o Tibialis posterior o Flexor digitorum longus o Flexor hallucis longus ________________________________________ 3. At the Ankle (Tarsal Tunnel) • Passes deep to the flexor retinaculum • Runs posterior to the medial malleolus • Arrangement from anterior → posterior (Tom, Dick, And Very Nervous Harry): 1. Tibialis posterior tendon 2. Flexor digitorum longus tendon 3. Posterior tibial artery 4. Posterior tibial vein 5. Tibial nerve 6. Flexor hallucis longus tendon • The tibial nerve lies: o Between posterior tibial vessels and FHL tendon ________________________________________ Terminal Branches At or just distal to the flexor retinaculum, the tibial nerve divides into: • Medial plantar nerve • Lateral plantar nerve These supply: • Sensory innervation to the sole of the foot • Motor innervation to intrinsic foot muscles ________________________________________ Sensory Distribution • Heel (via medial calcaneal branches) • Entire plantar surface of the foot • Posterior sole ________________________________________ Motor Function • Plantar flexion • Toe flexion • Inversion of the foot • Only ankle-level nerve that produces a motor response on stimulation → plantar flexion of toes ________________________________________ 2. Common Peroneal (Fibular) Nerve • Terminal branch of sciatic nerve • Runs along medial border of biceps femoris • Passes over lateral head of gastrocnemius • Winds around neck of fibula • Divides into: o Deep peroneal nerve o Superficial peroneal nerve ________________________________________ 3. Deep Peroneal Nerve • Begins deep to peroneus longus • Passes under extensor digitorum longus • Lies anterior to interosseous membrane • Runs with anterior tibial artery (Dorsalis Pedis Artery) • Located between: o Tibialis anterior o Extensor hallucis longus • Supplies first dorsal web space ________________________________________ 4. Superficial Peroneal Nerve • Lies between peroneus longus and fibula • Supplies: o Peroneus longus o Peroneus brevis • Pierces deep fascia in lower third of leg • Becomes subcutaneous • Supplies: o Distal anterolateral leg o Most of dorsum of foot o Most toes ________________________________________ 5. Sural Nerve • Formed by: o Medial sural cutaneous nerve (tibial) o Sural communicating branch (common peroneal) • Lies with short saphenous vein • Passes behind lateral malleolus • Supplies: o Posterolateral lower leg o Lateral foot o Heel o Posterior sole ________________________________________ 6. Saphenous Nerve • Only femoral nerve contribution below knee • Arises in femoral triangle • Travels in adductor canal • Emerges between sartorius and gracilis • Becomes subcutaneous at medial knee • Travels with great saphenous vein • Supplies medial ankle and foot ________________________________________ Indications of Ankle block • Surgery below ankle joint o Forefoot o Midfoot • Can be used with ankle tourniquet • Allows immediate mobilisation • Safe for bilateral blocks • Analgesia lasts 18–24 hours ________________________________________ Contraindications 1. Patient refusal 2. Infection at injection sites ________________________________________ Key Practical Points 1. Not all five nerves must be blocked – tailor to surgical site 2. Confirm nerves by tracking proximally and distally on ultrasound 3. 4 of 5 nerves lie close to blood vessels 4. Scan cephalad to ankle joint – scanning at ankle is difficult due to probe contact issues 5. Multiple injections → sedation improves comfort ________________________________________ Ultrasound-Guided Ankle Block Preparation Patient • Supine position • Position of patient’s leg varies depending on which nerve is being blocked. o Leg placed over the nonoperative leg, foot slightly externally rotated, knee flexed- figure of four (for saphenous/tibial nerve). o Knee flexed and leg in neutral position (Deep peroneal). o Knee flexed and slightly internally rotated with foot resting on the bed (Sural nerve). o Leg on the bed slightly internally rotated (superficial peroneal nerve) • Light sedation may be helpful as multiple injections are needed • If the block is done for postoperative pain relief, then we perform the block under general anaesthesia General Ultrasound Principles • Scan cephalad to the ankle joint o at the level of the medial malleolus, achieving good probe–skin contact is difficult due to the concave contour between the medial malleolus and the heel. o Slightly more subcutaneous tissues- needle less likely to contact bone/periosteum- leading to less pain. • Identify nerves by: o Relation to blood vessels (four out of five nerves are close to blood vessels) o Tracking proximally and distally • Use in-plane needle approach if possible (not possible for deep peroneal nerve) • Aspirate frequently Equipment • High-frequency ultrasound probe + cover + gel • 50 mm insulated stimulating needle o Tibial nerve stimulation → plantar flexion • 23G hypodermic needle (other nerves) or use the 50 mm insulated needle • Local anaesthetic: o 0.5% levobupivacaine o ~5 mL per nerve • 2% chlorhexidine ________________________________________ Individual Nerve Blocks ________________________________________ 1. Tibial Nerve Block (Most Important) Position • Probe placed transversely just above the medial malleolus Ultrasound Anatomy • Posterior tibial artery (pulsatile, anechoic) • Posterior tibial veins — these are usually present as two venae comitantes on either side of the posterior tibial artery. Their position should be identified initially; however, during scanning the pressure applied with the probe to visualise the tibial nerve often compresses the veins, making them difficult or impossible to see. • Tibial nerve: o Hyperechoic o Lies posterior or posterolateral to artery o Between vessels and flexor hallucis longus tendon Technique 1. Identify posterior tibial artery using colour Doppler 2. Locate tibial nerve adjacent to it 3. Insert needle in-plane from posterior side 4. Advance toward nerve 5. Optional nerve stimulation → toe plantar flexion 6. Inject 5 mL LA to surround nerve ________________________________________ 2. Deep Peroneal Nerve Block Position • Probe placed transversely on anterior ankle, just above ankle joint Ultrasound Anatomy • Anterior tibial artery (Dorsalis pedis artery) • Deep peroneal nerve: o Small hyperechoic structure o The deep peroneal nerve has a variable position and may lie medial or lateral to the anterior tibial artery, depending on the level and orientation of the ultrasound scan. o Between tibialis anterior and extensor hallucis longus Technique 1. Identify anterior tibial artery 2. Locate nerve lateral to artery 3. Difficult to insert needle in-plane and out of plane insertion may be necessary. 4. Deposit 3–5 mL LA around nerve ________________________________________ 3. Superficial Peroneal Nerve Block Position • Probe placed on anterolateral lower leg, cephalad to the ankle joint. Ultrasound Anatomy Place the probe on the anterolateral aspect of the lower leg, cephalad to the ankle joint. Identify the acoustic shadow of the fibula. On either side of this shadow, the peroneal muscles and the extensor digitorum longus muscle can be seen. As the probe is moved proximally, the fibular shadow becomes deeper and the peroneal muscles and extensor digitorum longus move closer together. At this level, the superficial peroneal nerve is visualised superficial to the fascia. With further proximal movement of the probe, the nerve can be seen piercing the fascia and then lying deeper between the peroneal muscles and extensor digitorum longus. Technique 1. Identify nerve in superficial to the fascia 2. Use shallow in-plane approach 3. Inject 3–5 mL LA subcutaneously around nerve ________________________________________ 4. Sural Nerve Block Position • Probe placed posterolateral to ankle, above lateral malleolus Ultrasound Anatomy Place the probe over the Achilles tendon just cephalad to the lateral malleolus. Identify the short saphenous vein. Sural nerve is seen as a hyperechoic nerve lying adjacent to vein. Technique 1. Identify small saphenous vein 2. Locate sural nerve next to it 3. Insert needle in-plane 4. Inject 3–5 mL LA around nerve ________________________________________ 5. Saphenous Nerve Block Position • Probe placed on the medial side of the leg at midleg level Ultrasound Anatomy Identify Great saphenous vein. Usually either a single nerve or branches are seen next to vein. It is small, hyperechoic. Technique Identify great saphenous vein, locate nerve next to vein, inject 3–5 mL local anaesthetic superficially, creating a broad subcutaneous spread around the nerve. Eu sed eIn minim cupidatat non
officia
Excepteur do u voluptate sunt labore.Do ea amet enim in
officia
Dolor qui ex in magna amet offideserunt occaecat quis ea excepteur veniam.Nulla officia pariatur
elit
Dolor ea in adipisicing consequat eiusmod in non dolor anim. Dolore velit minim culpa ullamco elit ipsum veniam esse, deserunt in aute, commodo in et laboris anim sed. Amet, cillum nulla esse laboris nisi pariatur dolor, excepteur occaecat id in ad pariatur occaecat nulla. Ut quis consequat ad fugiat amet, et magna. Sit adipisicing, incididunt quis ut nulla culpa ut enim magna qui aute non? Aliqua est proident lorem, sed nostrud aliquip tempor et cupidatat dolore voluptate non sint duis in. Cupidatat, minim sit ex magna ipsum non in, voluptate excepteur nulla minim sint dolore magna sint? Adipisicing do minim dolore ut aliqua id non officia, sed pariatur sed ipsum, in deserunt aute sunt ipsum. Cillum culpa duis aliqua. Est in id culpa qui do, occaecat enim do sunt incididunt. Voluptate ut do incididunt ut ea consectetur ipsum in.
