Anteromedial approach to the ankle joint

The anteromedial approach to the ankle joint is highly valuable for managing various intra-articular fracture patterns of the ankle, particularly those involving the medial malleolus.

Indications

The anteromedial approach to the ankle joint is indicated for the following procedures:

1. Open reduction and internal fixation (ORIF) of medial malleolus fractures.
2. Open reduction and internal fixation (ORIF) of pilon fractures.
3. Repair of the deltoid ligament.

Patient Positioning

• Position: Supine.
• Foot placement: Place the foot in slight external rotation to improve visualization of the medial malleolus. If a bump was used, it can be removed to allow for external rotation of the extremity.

Landmarks and Incision

• Make a 10 cm curved longitudinal incision over the medial ankle, beginning 5 cm proximal to the medial malleolus over the subcutaneous tibia.
• Continue the incision over the anterior third of the medial malleolus. The incision can be curved anteriorly at the tip to enhance visualization of the ankle joint.
• Conclude the incision 5 cm distal and 5 cm anterior to the tip of the medial malleolus.

Internervous Plane

There is no true internervous plane for the anteromedial approach to the ankle joint.

Superficial Dissection

• Mobilize the skin flaps.
• Identify and protect the great saphenous vein (V. saphena magna), located directly anterior to the medial malleolus.
• Identify and protect the saphenous nerve (Nervus saphenus longus), if possible, as it lies adjacent to the vein.
• Remove any remaining soft tissue down to the periosteum.

Deep Dissection

• Expose the fracture site for a medial malleolus fracture.
• Make a small incision into the anterior joint capsule to visualize the joint and the dome of the talus.
• Split the fibers of the deltoid ligament to allow hardware to sit directly on the bone.
• The posterior tibial tendon should be visualized to confirm it remains intact.

Dangers

Structures at risk during the anteromedial approach to the ankle include:

1. The saphenous nerve: Prevent injury by protecting and preserving the great saphenous vein. The nerve is often too small for direct visualization. Damage can lead to the formation of painful neuromas and numbness over the midfoot.
2. The great saphenous vein: Prevent injury by carefully mobilizing the anterior skin flaps. Preservation is ideal so the vein can be used as a graft in the future.

References

1. Book “Surgical Exposures in Orthopaedics” – 4th Edition
2. Campbell’s Book “Operative Orthopaedics”, 12th Edition