The posterolateral approach to the ankle gives direct access to the distal fibula from behind the peroneal tendons, and it has become the workhorse exposure for oblique lateral malleolus fractures that call for antiglide plating. It also opens the way to a posterior malleolar fragment through the same incision, which a standard lateral approach cannot do. This guide sets out the exposure step by step — positioning, incision, the interval between the peroneal tendons and the flexor hallucis longus, plate placement and closure — using the fibular plating systems we supply at BoneCraft as the hardware reference. The operating surgeon decides the final tactic for each fracture.
When the posterolateral approach is the right choice
Most simple lateral malleolar fractures can be plated through a direct lateral incision. The posterolateral approach earns its place in three situations. First, oblique fractures of the distal fibula where a posterior plate can work in antiglide mode, pressing the spike of the proximal fragment into the distal fragment as the screws tighten. Second, fracture-dislocations with a posterior malleolar fragment, where the same incision serves both the fibula and the posterior tibia. Third, cases where the skin over the lateral malleolus is blistered or contused and the surgeon wants the incision away from compromised tissue.
Preoperative planning
AP, lateral and mortise views of the ankle classify the fracture by the level of the fibular fracture line against the syndesmosis, and a CT scan is added whenever a posterior malleolar fragment is suspected. Planning settles three questions before the patient enters the room: whether the fracture suits antiglide mechanics, whether posterior malleolar work will share the incision, and which plate family and screw inventory must be opened. Answering these on the images, not on the table, shortens the case and keeps the implant set complete.
Positioning and landmarks
The patient is placed in a lateral decubitus position or prone, depending on whether posterior malleolar work is planned. A bump under the ipsilateral hip with the leg internally rotated is the common compromise when only the fibula needs attention. The landmarks are the posterior border of the fibula, the lateral border of the Achilles tendon, and the course of the sural nerve, which runs from the midline of the calf toward the lateral border of the foot and crosses the surgical field. A thigh tourniquet is optional but keeps the field clean during the approach.
Incision and superficial dissection
The incision runs along the posterior border of the fibula, roughly halfway between the fibula and the lateral edge of the Achilles tendon, extending from several centimeters above the fracture down toward the tip of the lateral malleolus. The sural nerve and the small saphenous vein travel together in the subcutaneous layer and are identified before any deep dissection begins; the nerve is gently mobilized and protected through the rest of the case. The peroneal tendon sheath is opened at its posterior edge, and the tendons are retracted anterolaterally with the flap. Deep dissection continues on the posterior face of the fibula, sweeping the flexor hallucis longus off the interosseous membrane to expose the posterior tibia when a posterior malleolar fragment needs reduction.
Fracture reduction and plate mechanics
The fracture site is cleaned of clot and interposed periosteum. Oblique distal fibula fractures are reduced with a pointed clamp, and length and rotation are confirmed against the intact tibial side under fluoroscopy. The defining feature of this approach is the antiglide plate: a plate contoured to the posterior surface of the fibula, placed so that it buttresses the proximal spike. As the first distal screw is tightened, the plate slides the spike down the slope of the fracture and compresses it. A lag screw through the plate across the fracture line adds interfragmentary compression where the geometry allows. Lateral plating remains the alternative when the fracture pattern is transverse or when the surgeon prefers a neutralization construct with an independent lag screw.
| Factor | Posterolateral antiglide plate | Lateral plate |
|---|---|---|
| Best fracture pattern | Oblique, posterior spike | Transverse, comminuted |
| Plate function | Buttress and compression | Neutralization or bridge |
| Access to posterior malleolus | Same incision | Not available |
| Hardware prominence | Low, behind the bone | Higher, under the skin |
BoneCraft stocks the hardware for both tactics: the posterolateral distal fibula plate for antiglide work, the distal lateral fibula plate for lateral placement, and anatomic locking versions in the anatomic fibula locking plate line. The complete range sits in the foot and ankle collection.
Syndesmosis assessment and fixation
Once the fibula is fixed, syndesmotic stability is tested. A lateral stress on the fibula with a clamp — the Cotton or hook test — and an external rotation stress under fluoroscopy show any widening of the tibiofibular clear space. An unstable syndesmosis is reduced with a clamp placed through the same field and fixed according to the surgeon's preference. The fibula must sit correctly in the incisura before any syndesmotic fixation is placed, because a malreduced fibula guarantees a malreduced syndesmosis.
Closure and soft tissue considerations
The peroneal tendon sheath is repaired over the tendons to prevent subluxation. The subcutaneous layer is closed with fine absorbable sutures, keeping tension off the skin edge, and the skin is closed with the surgeon's preferred method. The posterolateral incision generally heals well because it sits over muscle rather than over the subcutaneous border of the fibula, and the hardware behind the bone rarely troubles the patient. Postoperative weight bearing is set by the operating surgeon according to fracture stability, bone quality and any associated injuries.
Pitfalls worth knowing
Three errors recur in the literature and in practice. Injury to the sural nerve during superficial dissection leaves numbness along the lateral foot — the nerve must be found and protected before deep work starts. Failure to repair the peroneal tendon sheath invites tendon subluxation over the plate. And accepting a shortened or externally rotated fibula before plating builds malreduction into every later step, including syndesmotic fixation. Length, rotation and the talus position in the mortise are checked on a true mortise view before the wound is closed.
Sourcing fibular plating systems
BoneCraft is an independent distributor of genuine Zimmer Biomet trauma implants, including the fibular plating families referenced in this guide. Hospitals and distributors who need anatomic fibula plates, posterolateral plates and locking screws from stock can contact our team for availability and lot documentation.
Frequently asked questions
What fractures are best treated through the posterolateral approach?
Oblique distal fibula fractures with a posterior spike suit antiglide plating through this approach. It is also the approach of choice when a posterior malleolar fragment needs reduction and fixation through the same incision.
Which nerve is at risk during this approach?
The sural nerve. It crosses the operative field with the small saphenous vein in the subcutaneous tissue and must be identified and protected before deep dissection begins.
What is an antiglide plate?
A plate contoured to the posterior surface of the fibula that buttresses the proximal fracture spike. As its screws are tightened, the plate presses the spike into the distal fragment and compresses the fracture, so it works without a separate compression device.
Can the posterior malleolus be reached through the same incision?
Yes. Deep dissection between the peroneal tendons and the flexor hallucis longus exposes the posterior tibia, which allows reduction and screw fixation of a posterior malleolar fragment without a second incision.
Why is peroneal tendon sheath repair important?
An unrepaired sheath lets the peroneal tendons subluxate over the fibular plate, causing snapping, pain and tendon wear. A simple repair of the sheath at closure prevents this.
How is syndesmotic stability tested after fibular fixation?
With a lateral pull on the fibula using a clamp under fluoroscopy and with an external rotation stress view. Widening of the tibiofibular clear space indicates instability that needs fixation.
Is the hardware prominent behind the fibula?
Posterolateral plates sit on the posterior surface of the bone under muscle cover, so they are less prominent than lateral plates under the thin skin of the lateral malleolus. Removal rates are correspondingly lower.
Zimmer Biomet and ALPS are trademarks of their respective owner. BoneCraft is an independent distributor of genuine Zimmer Biomet products and is not affiliated with, sponsored by, or endorsed by the trademark owner.
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