Approach to the Fibula (Lateral, Peroneal-Protecting)

What it exposes. The lateral approach gives direct, extensile access to the entire fibular shaft — from the fibular neck proximally to the lateral malleolus distally — and is the standard exposure for fibular ORIF, syndesmotic stabilisation, and middle-third strut graft harvest. It works a true internervous plane and, executed subperiosteally, keeps the peroneal vessels posterior and protected. Primary indications.

• Fibular shaft fractures requiring ORIF (isolated or combined with tibial injury).
• Weber B and C ankle fractures needing fibular plating and syndesmotic stabilisation.
• Fibular bone graft or strut harvest for reconstruction (middle third preferred).
• Corrective fibular osteotomy for malunion, ankle deformity, or limb-length issues.
• Peroneal nerve exploration or decompression at the fibular neck.
• Proximal fibular pathology (tumours, nonunions) requiring exposure. Why this approach is chosen. The lateral route provides direct access to the whole fibular shaft while protecting the superficial peroneal nerve when properly executed. It allows plate placement on the lateral or posterolateral surface, is extensile in both directions, and subperiosteal technique keeps the peroneal vessels posterior and safe. Contraindications. Active infection over the proposed incision; severe soft-tissue compromise requiring staged or alternative surgery; isolated medial pathology better addressed through a medial approach; and unplanned common peroneal nerve exploration proximally without adequate preparation. Alternative approaches. A posterolateral approach to the tibia-fibula for combined posterior exposure; an anterolateral approach when anterior-compartment access is also needed; and a medial tibial approach when only tibial shaft work is required. Position and landmarks. Supine with a bump under the ipsilateral hip to internally rotate the leg, or lateral decubitus with the affected side up when combined posterior access is anticipated. The knee is slightly flexed to relax gastrocnemius-soleus, the foot is free-draped for intra-operative ankle motion, and a high thigh tourniquet is used when a bloodless field is needed. Palpable landmarks are the fibular head, the subcutaneous fibular shaft, and the lateral malleolus; the superficial peroneal nerve is often visible subcutaneously in thin patients in the distal third, and the sural nerve runs posterior to the lateral malleolus with the short saphenous vein. Plan a longitudinal incision along the posterior border of the fibula, 4 to 8 cm for mid-shaft work and longer for extensile needs, centred over the pathology.

Work down through the layers along the posterior fibular border: find and protect the superficial peroneal nerve in the distal third, open the lateral-compartment fascia, develop the internervous plane, and dissect strictly subperiosteally to keep the peroneal vessels posterior.

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Anatomy that governs the exposure. The fibular shaft is triangular in cross-section with anterior, posterior, and lateral (subcutaneous) borders; the middle third is the usual strut-graft donor site, and the distal fibula forms the lateral malleolus of the ankle mortise. The deep dissection passes between two compartments supplied by different nerves, which is the basis of the internervous plane.

Internervous plane. The deep plane runs between the peroneal muscles (superficial peroneal nerve) anteriorly-laterally and the posterior-compartment muscles (tibial nerve) posteriorly. The peronei are retracted anteriorly as a unit and the posterior compartment falls back, exposing the fibular shaft without crossing nerve territories. Superficially there is no classical internervous plane — the incision crosses subcutaneous tissue and the lateral-compartment fascia, so the superficial peroneal nerve must be identified where it pierces the fascia before any deep retraction.

Structures at risk, by layer.

If the SPN is injured. A transected nerve should undergo primary microsurgical repair where possible; a neurapraxia is observed, with an AFO if foot drop is present and EMG at three weeks; permanent sensory loss is managed with neuroma care, desensitisation, and revision surgery if symptomatic. Extensile options. Extend proximally toward the fibular head for peroneal nerve exploration or proximal pathology — identify the common peroneal nerve early as it winds around the neck. Extend distally to the tip of the lateral malleolus for Weber B/C ankle fractures and syndesmotic stabilisation, protecting the peroneal tendons and sural nerve. For combined tibial and fibular pathology, the lateral fibular approach can be combined with anterolateral or posterolateral tibial approaches through separate or connected incisions. Closure. Copious irrigation and meticulous haemostasis, particularly around the peroneal vessels. Release the tourniquet before closure to confirm haemostasis. Place a drain only if significant bleeding or dead space is expected, exiting it away from the superficial peroneal nerve course. Close the fascial layer loosely with absorbable suture to avoid compartment syndrome, approximate subcutaneous tissue, and close skin with staples or interrupted sutures. Confirm fibular reduction, plate position, and the ankle mortise on AP, lateral, and mortise views, and document SPN function immediately after surgery.

• Fibular plating (ankle and shaft fractures) — apply a 3.5 mm or 2.7 mm plate to the lateral or posterolateral surface; for Weber B and C fractures achieve anatomic reduction of the lateral malleolus and assess syndesmotic stability with the hook test or external rotation stress, using lag screws with neutralisation or buttress plating as indicated.
• Fibular strut graft harvest — expose the middle third, cut the required length with an oscillating saw under direct vision while protecting the peroneal vessels posteriorly, and preserve at least 6 to 8 cm of distal fibula for ankle stability; fill or plate the defect if a large graft is taken.
• Corrective fibular osteotomy — mark the planned level, perform the osteotomy with a saw or osteotomes under direct vision, correct rotation, length, or angulation, stabilise with plate and screws, and assess the ankle mortise fluoroscopically.
• Peroneal nerve exploration at the fibular neck — via the proximal extension, identifying and protecting the common peroneal nerve as it winds around the neck.
• Proximal fibular pathology (tumours, nonunions) through the extended proximal exposure.

The lateral approach to the fibula is used worldwide for fibular fixation, graft harvest, and osteotomy, and the principles are consistent across advanced orthopaedic practice and equivalent examination systems: SPN identification in the distal third and subperiosteal technique to protect the peroneal vessels are universal requirements.

Registry and population evidence. Fibular fractures occur in about 10 to 15 percent of all lower-limb fractures, and ankle fractures requiring fibular plating are the most common indication for this approach. Donor-site morbidity after fibular graft harvest is primarily transient SPN sensory disturbance in 5 to 10 percent. In high-resource settings, dedicated small-fragment and mini-fragment locking systems are standard; in resource-limited settings, one-third tubular and 3.5 mm reconstruction plates give equivalent outcomes when technique is sound, with external fixation used more often for temporisation. Consent (globally applicable). Discuss superficial peroneal nerve sensory loss (5 to 10 percent transient, less than 2 percent permanent), peroneal vessel injury (rare with correct technique), infection (1 to 3 percent), nonunion (2 to 5 percent), and ankle instability after graft harvest if the distal fibula is not preserved.