Access to the lateral malleolus

Introduction

The approach to the lateral malleolus is primarily used for open reduction and internal fixation of lateral malleolus fractures.

Other applications of the Lateral Malleolus Approach include:

1. Open reduction and internal fixation of syndesmosis ligaments.
2. Percutaneous placement of syndesmotic screws.
3. Approach to the posterolateral tibia.

Patient Positioning

Place the patient supine on the operating table with a sandbag under the buttock of the affected extremity. The sandbag causes medial rotation of the limb, bringing the lateral malleolus forward and making it easier to access.

Landmarks and Incision

• Landmarks:
  • Lateral malleolus.
  • Short saphenous vein.
• Incision:
  • Make a 10–15 cm longitudinal incision along the posterior border of the fibula down to its distal end, and continue it for another 2 cm. For fracture surgery, center the incision at the level of the fracture.

Internervous Plane

• For the approach to the lateral malleolus, there is no internervous plane because dissection is carried down to a subcutaneous bone.
• In higher fibular fractures, the internervous plane lies between the peroneus tertius muscle, innervated by the deep peroneal nerve, and the peroneus brevis muscle, innervated by the superficial peroneal nerve.

Superficial Dissection

• Lift the skin flaps, taking care not to damage the short saphenous vein, which lies behind the lateral malleolus. The sural nerve, which runs with the short saphenous vein, should also be preserved.

Deep Dissection

• The periosteum on the subcutaneous surface of the fibula is incised longitudinally, and just enough periosteum is removed at the fracture site to adequately expose the fracture. Ensure all dissection is strictly subperiosteal, as the terminal branches of the peroneal artery, located near the lateral malleolus, can be damaged.
• Remove only as much periosteum as necessary for precise reduction; periosteal stripping significantly impairs the blood supply to the bone in fractures.

Approach Extension

Proximal Extension:

• The approach to the lateral malleolus can be extended proximally by lengthening the incision along the posterior edge of the fibula and incising the deep fascia in line with the skin incision.
• Develop a new plane between the peroneal muscles, innervated by the superficial peroneal nerve, and the flexor muscles, innervated by the tibial nerve.
• The upper third of the fibula can be exposed if the common peroneal nerve is identified near the knee and traced down to the ankle.

Distal Extension:

• To extend the approach to the lateral malleolus distally, carry the incision down along the lateral side of the foot.
• Identify the peroneal tendons and incise the peroneal retinacula.
• Release the fat pad in the sinus tarsi and the origin of the extensor digitorum brevis muscle to expose the calcaneocuboid joint on the lateral side of the tarsus.

The approach to the lateral malleolus can be extended distally to connect with:

1. Ollier’s lateral approach to the tarsus.
2. Kocher’s lateral approach to the ankle and tarsus.
3. Lateral approach to the calcaneus.

Posterior Extension:

• Can access the posterolateral tibia for fixation.
• The interval lies between the peroneal muscles/tendons and the flexor hallucis longus muscle.

Dangers

Structures at risk during the approach to the lateral malleolus include:

1. Sural nerve: Its injury can lead to the formation of a painful neuroma and numbness along the lateral skin of the foot.
2. Short saphenous vein.
3. Terminal branches of the peroneal artery: These lie deep on the medial surface of the distal fibula. They can be damaged if dissection is not subperiosteal and may form a hematoma after removal of a tourniquet.
4. Superficial peroneal nerve: The superficial peroneal nerve crosses from posterior to anterior over the fibular shaft at the proximal end of the incision.

References

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