Approach to the Proximal Fibula and Common Peroneal Nerve

What it exposes. This approach gives direct access to the fibular head, the fibular neck, the common peroneal nerve (CPN) as it winds around the neck, the posterolateral corner (PLC) attachments on the head, and the proximal tibiofibular joint. It is designed around one overriding principle — mandatory early identification and protection of the CPN before any deep bone work. Primary indications. - Common peroneal nerve decompression and neurolysis at the fibular neck (the most common use).

• Fibular head excision for tumour, symptomatic nonunion, or arthritis.
• Posterolateral corner reconstruction — fibular-head tunnel placement and graft passage.
• Proximal tibiofibular joint arthrotomy, stabilisation, or arthrodesis.
• Tumour biopsy or resection involving the proximal fibula with nerve preservation.
• Open reduction and internal fixation of selected proximal fibula fractures, and revision surgery around the fibular head. Why this approach is chosen. The proximal fibula is the site where the CPN is most susceptible to compression and injury. Direct exposure allows safe nerve decompression, secure reattachment of posterolateral corner structures, and access to the fibular head for oncologic or reconstructive procedures, with extensile access proximally along the biceps tendon and distally along the fibular shaft. Contraindications. Active infection over the proposed incision; severe soft-tissue compromise requiring delayed surgery; medical instability precluding positioning; and isolated medial or anterior compartment pathology better addressed through another approach. Alternative approaches. An anterolateral approach to the knee for intra-articular pathology without CPN involvement; a posterolateral approach to the tibia for tibial plateau fractures requiring buttress plating; and a lateral approach to the fibular shaft for mid-shaft fibula fractures or nonunion. Position & landmarks. Supine on a radiolucent table with the knee flexed 30 to 40 degrees over a bolster (this relaxes the CPN and is essential), the hip slightly externally rotated to bring the fibular head forward, and a high thigh tourniquet inflated after draping. Palpate and mark the fibular head (the most prominent lateral landmark), the lateral joint line, the biceps femoris tendon proximally, and the fibular shaft distally; the CPN can often be rolled under a finger as it crosses the fibular neck. The lazy-S incision is centred over the fibular head: the proximal limb curves posteriorly along the biceps tendon and the distal limb runs along the posterior border of the fibular shaft, totalling 6 to 8 cm and extendable in either direction. Document dorsiflexion and eversion before draping.

The exposure is built around the nerve. First understand the regional anatomy, then find and protect the CPN, and only then perform strictly subperiosteal dissection on the fibular neck and head.

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Regional anatomy that dictates the technique. - The CPN (L4-S2) courses along the posterior border of the biceps femoris, then winds laterally around the fibular neck 1 to 2 cm distal to the fibular head, and divides into the deep and superficial peroneal nerves within the peroneal compartment. Before reaching the neck it lies superficial to the lateral head of gastrocnemius and deep to the biceps.

• The anterior tibial artery arises from the popliteal artery at the lower border of popliteus and passes forward through the interosseous membrane about 2 to 3 cm distal to the fibular head — the structure most at risk from anterior or blind dissection.
• The biceps femoris tendon and the lateral collateral ligament both insert on the fibular head; the peroneus longus originates from the proximal fibula and lateral tibial condyle, and the soleus has a proximal origin from the fibular head and posterior tibia.

Structures at risk, by layer

Extensile options. Extend proximally along the posterior border of the biceps femoris tendon to reach the posterolateral capsule and popliteal fossa for more extensive PLC reconstruction. Extend distally along the posterior border of the fibular shaft to access the proximal fibular diaphysis for longer plate fixation or more distal nerve exploration. Closure. Reattach the biceps femoris and LCL to the fibular head with heavy non-absorbable suture if detached; close the peroneal compartment fascia loosely to avoid compartment syndrome; approximate subcutaneous tissue and close skin with staples or interrupted sutures. Apply a knee brace in slight flexion. CPN injury management. If the nerve is transected intra-operatively, perform primary repair or a nerve graft for a gap; for post-operative foot drop, manage with an ankle-foot orthosis, physiotherapy, and serial nerve-conduction studies. Most neuropraxias recover within 3 to 6 months and axonotmesis within 6 to 12 months; explore if there is no recovery by 3 months with positive EMG changes.

• Common peroneal nerve decompression — nerve exploration and release at the fibular neck; the principal operation through this exposure.
• Fibular head excision for tumour (e.g. osteochondroma), symptomatic nonunion, or arthritis, with preservation and reattachment of posterolateral corner structures.
• Posterolateral corner reconstruction — fibular-head tunnel drilling (anterior-to-posterior) and graft passage for chronic posterolateral rotatory instability.
• Proximal tibiofibular joint arthrotomy, stabilisation, or arthrodesis.
• Tumour biopsy or resection with appropriate margins, and ORIF of selected proximal fibula fractures.