When performing an intraarticular ankle block, an anterolateral approach is preferred.
Indications for Use
An intraarticular ankle block is used for ankle fracture reduction.
Precautions
- 1.
Use of the lateral malleolus as a landmark helps prevent damage to the dorsal cutaneous nerve.
- 2.
In patients with significant swelling, tendinous structures are difficult to palpate.
Pearls
- 1.
A topical anesthetic with ethyl chloride may be used to reduce patient discomfort.
- 2.
Positioning the ankle in slight plantarflexion provides easier access to the joint.
Equipment
- 1.
Antiseptic: A chlorhexidine prep stick
- 2.
Syringe: A 10-mL syringe
- 3.
Anesthetics:
- a.
Lidocaine: 5 mL of 2%
- b.
Bupivacaine: 5 mL of 0.5%
- a.
- 4.
Needle: A 1½-in., 22-gauge needle
- 5.
Sterile gloves
- 6.
4 × 4 in. gauze
Basic Technique
- 1.
The patient should be supine with the ankle in slight plantarflexion.
- 2.
Landmarks:
- a.
Lateral malleolus
- b.
Peroneus tertius tendon
- (1)
The site of entry is 2.5 cm proximal and 1.3 cm anterior to the tip of the lateral malleolus.
- (2)
This site of entry is immediately lateral to the peroneus tertius tendon.
- (1)
- a.
- 3.
Steps:
- a.
Position the patient.
- b.
Palpate the landmarks.
- c.
Prepare the skin with an antiseptic solution.
- d.
Place sterile drapes around the ankle.
- e.
Administer a topical anesthetic if desired.
- f.
Inject the anesthetic into the joint.
- g.
Place a sterile bandage over the injection site.
- a.
Detailed Technique
- 1.
Position the patient so that he or she is supine with the ankle in slight plantarflexion.
- 2.
Palpate the landmarks:
- a.
Feel the most distal aspect of the lateral malleolus.
- b.
The site of entry is slightly more than the breadth of one finger proximal and half the breadth of a finger anterior.
- c.
Mark this site.
- a.
- 3.
Prepare the skin with an antiseptic solution. Perform a wide preparation.
- 4.
Place sterile drapes around the ankle. Drape out proximally, distally, and laterally.
- 5.
Administer a topical anesthetic if desired.
- 6.
Inject the anesthetic into the joint ( Fig. 7.1 ):
- a.
Enter at a 60-degree angle to the skin.
- b.
Insert the needle in the posterior and medial direction.
- c.
Advance 0.5–1 cm to enter the joint.
- d.
Inject the anesthetic.
- a.
