What is an ankle block (regional anesthesia)?

From the Guidelines

An ankle block is a regional anesthesia technique that numbs the foot and ankle by blocking five peripheral nerves: the tibial, deep peroneal, superficial peroneal, sural, and saphenous nerves.

Definition and Purpose

An ankle block is used for foot and ankle surgeries, providing effective pain control without affecting motor function above the ankle. The goal of this technique is to provide targeted pain relief while minimizing the risks associated with general anesthesia or neuraxial blocks.

Procedure and Technique

To perform an ankle block, local anesthetics like lidocaine 1-2% or bupivacaine 0.25-0.5% are injected at specific anatomical sites around the ankle, as described in studies such as 1. Typically, 3-5 mL of anesthetic is used for each nerve, with a total volume of 15-25 mL. The onset of action is usually within 10-15 minutes, and the duration varies from 2-4 hours for lidocaine to 8-12 hours for bupivacaine. Adding epinephrine (1:200,000) can prolong the effect and reduce systemic absorption.

Benefits and Advantages

The use of regional anesthesia techniques, including ankle blocks, has been shown to be effective in managing acute pain associated with traumatic fractures in elderly patients, decreasing the use of opioids, pain, and length of hospital stay 1. Additionally, studies have demonstrated that peripheral nerve blocks, such as the ankle block, can provide good pain control in patients presenting with hip fractures [@353, @354].

Potential Complications

Potential complications of ankle blocks include vascular puncture, nerve injury, infection, and systemic toxicity from local anesthetics. However, the use of ultrasound guidance can improve accuracy and success rates while reducing the risk of complications.

Key Points

• Ankle blocks provide targeted pain relief without affecting motor function above the ankle
• Local anesthetics like lidocaine or bupivacaine are used for the procedure
• The technique is beneficial for foot and ankle surgeries, providing effective pain control and minimizing the risks associated with general anesthesia or neuraxial blocks
• Ultrasound guidance improves accuracy and success rates while reducing the risk of complications, as supported by studies such as 1

From the Research

Definition and Purpose of Ankle Block

• Ankle block is a type of regional anesthesia that involves injecting a local anesthetic around the nerves in the ankle to numb the foot and ankle area 2.
• The primary purpose of an ankle block is to provide surgical anesthesia and postoperative analgesia for foot and ankle surgeries 2, 3.

Techniques and Approaches

• Ankle blocks can be performed using different approaches, including anatomic landmark-guided (ALG) and ultrasound-guided (USG) techniques 2.
• The choice of approach may depend on the surgeon's or anesthesiologist's preference and the specific surgical procedure being performed 2.

Efficacy and Safety

• Studies have shown that ankle blocks are effective in providing postoperative analgesia and reducing pain scores in patients undergoing foot and ankle surgery 2, 4.
• The use of ankle blocks has also been associated with high patient satisfaction rates and minimal side effects 2, 3.
• However, as with any medical procedure, there are potential risks and complications associated with ankle blocks, including block failure, nerve injury, and local anesthetic toxicity 2, 3.

Local Anesthetics and Dosages

• Different local anesthetics, such as ropivacaine and bupivacaine, can be used for ankle blocks, and the choice of anesthetic may depend on the specific surgical procedure and the patient's medical history 2, 5.
• The dosage of local anesthetic used for ankle blocks can vary, but studies have shown that lower volumes of local anesthetic can be effective in achieving successful surgical anesthesia 5, 6.

Comparison with Other Anesthetic Techniques

• Ankle blocks have been compared to other anesthetic techniques, such as general anesthesia, and have been shown to have advantages in terms of reduced postoperative pain and faster recovery times 2, 3.
• However, the choice of anesthetic technique ultimately depends on the specific surgical procedure, the patient's medical history, and the surgeon's or anesthesiologist's preference 2, 3.