Ankle block

1. Ankle block Dr. S. Parthasarathy • MD., DA., DNB, MD (Acu), Dip. Diab. DCA, Dip. Software statistics • PhD (physio) • Mahatma Gandhi Medical college and research institute , puducherry India

2. Indication • Anaesthesia and postoperative analgesia of the foot. • Patient Selection • The ankle block is principally an infiltration block and does not require elicitation of paraesthesia. Thus, patient cooperation is not mandatory.

3. Anatomic Landmarks • Five nerves supply the foot, • four of which derive from the sciatic nerve (the tibial, the superficial and deep peroneal, the sural nerves) and • one from the femoral nerve (the saphenous nerve).

4. Anatomy of ankle nerves

5. Posterior tibial nerve

6. Cross section

7. Area of innervations

8. Technique • Generally, infiltration techniques are used for ankle blocks • The posterior tibial nerve can be blocked by a nerve stimulator technique. • All blocks are performed at the upper levels of the malleoli. • patients should be adequately sedated during this block because it is primarily a “volume” block.

9. Patient Position • The patient lies supine in neutral position or slight internal and then external rotation according to the nerve to be blocked Pillow to raise

10. SAPHENOUS NERVE BLOCK • The saphenous nerve runs in the superficial fascia in front of the medial malleolus accompanying the saphenous vein and innervates the medial side of the foot. • Technique • For saphenous nerve block, 3 to 5 mL of local anesthetic is injected subcutaneously on either side of the saphenous vein at the superior aspect of the medial malleolus

11. Saphenous N block

12. TIBIAL NERVE BLOCK • The tibial nerve lies under the flexor retinaculum at the midpoint between the medial malleolus and calcaneus • A point is marked midway between the medial malleolus and calcaneus. If the posterior tibial artery is palpated, the needle is inserted just posterior to the pulse, following which 3–5 mL of local anesthetic is injected.

13. TIBIAL NERVE BLOCK • Conversely, a 25-mm stimulating needle can be inserted at the skin mark and directed posterior to the tibial arterial pulse, looking • for plantarflexion of the toes.

14. Tibial and sural nerves

15. The sural nerve • located superficially between the lateral malleolus and the Achilles tendon. A 25-gauge, 3-cm needle is inserted lateral to the tendon and directed toward the malleolus as 5 to 10 mL of solution is injected subcutaneously

16. Peroneal nerves

17. DEEP PERONEAL NERVE BLOCK • A needle is inserted perpendicular to skin just lateral to the extensor hallucislongus tendon to contact the tibia. It is then withdrawn a few millimeters and 3 mL of local anesthetic is injected.

18. SUPERFICIAL PERONEAL NERVE BLOCK • Subcutaneous infiltration of 5 to 7 mL of local anaesthetic from the lateral to the medial malleolus.

19. Drugs • motor blockade is not often needed, pt. can walk with analgesia • Lower concentrations of local anesthetics may be used. • Practical choices are 1% lidocaine, 1% mepivacaine, 0.25% to 0.5% bupivacaine, and 0.2% to 0.5% ropivacaine. • Epinephrine ???, especially if injection is circumferential.

20. Anatomy and USG

21. Local injected

22. Deep peroneal nerve

23. Sural nerve

24. Complications • Induration may cause difficulty • Partial anaesthesia • Pain with mutiple injections • Infection • Haematoma • Nerve injury

25. Summary - ankle block Anaesthesia analgesia of foot Five nerves , 4 sciatic and one femoral Tibial, deep and sup. Peroneal, sural Saphenous Tibial and deep peroneal deeper (USG) Others superficial (normal technique) Technique Complications

26. We should know all blocks because we may need to anaesthetize such people

27. Thank you all