Free Vascularised Fibular Graft

Indication. A free vascularised fibular graft (FVFG) is reserved for situations where a conventional, non-vascularised graft would predictably fail — because the defect is too large, or the recipient bed is poorly vascularised, irradiated, or scarred. It is used to biologically reconstruct segmental long-bone defects and to revascularise the pre-collapse femoral head. The three situations you reach for it:

Why vascularised beats non-vascularised. Because the graft stays living:

• It maintains osteocyte viability and heals by primary bone healing rather than creeping substitution.
• It undergoes rapid hypertrophy in response to mechanical stress (Wolff's law).
• It performs far better in poorly vascularised or irradiated recipient beds.
• It has a lower rate of late stress fracture and resorption. Consent. Counsel donor-site morbidity specifically — great-toe/FHL flexion contracture, common peroneal nerve palsy (foot drop), and ankle instability — and recipient-site risks: flap/anastomosis failure, non-union at the docking sites, and stress fracture of the graft before it hypertrophies. Setup. Supine with a sandbag under the ipsilateral buttock to internally rotate the leg slightly, on a radiolucent table. Exsanguinate and inflate a high thigh tourniquet. The procedure is long and is ideally run with two surgical teams working concurrently — one harvesting the fibula while the other prepares the recipient site — to minimise ischaemia time. Loupe magnification for the harvest; the operating microscope for the anastomosis.

The goal is to harvest a length of living fibular diaphysis on its peroneal vascular pedicle, transfer it to the defect, secure it with rigid fixation, and re-establish blood flow by microvascular anastomosis. The lateral-leg exposure and pedicle isolation are the heart of the procedure — every later step depends on a clean, protected harvest.

View larger

Danger structures — what you protect at every step

Rehabilitation | Phase | Timing | Recipient limb | Donor leg & monitoring | |-------|--------|----------------|------------------------| | Early | 0–7 days | Elevate; avoid any pressure over the pedicle or skin paddle | Hourly skin-paddle checks (colour, capillary refill, Doppler signal) for the first 24–48 hours; LMWH for DVT prophylaxis (some centres add aspirin or dextran); encourage active ankle and toe motion, especially great-toe extension, to prevent FHL contracture | | Intermediate | 1–6 weeks | Strict non-weight-bearing | Progress the donor leg to full weight-bearing as tolerated; continue aggressive FHL and Achilles stretching; x-ray to confirm alignment and fixation | | Late | 2–12 months | Progress weight-bearing only as radiographic docking-site union and graft hypertrophy appear | The fibula takes 6 to 18 months to hypertrophy to match the recipient bone; high-impact activity is restricted until substantial hypertrophy is visible on imaging | Complications

Surgical anatomy and blood supply. The fibula is a long, thin strut of cortical bone — non-weight-bearing in its proximal and diaphyseal regions but critical for ankle stability distally. Its diaphyseal blood supply comes entirely from the peroneal artery, a branch of the tibioperoneal trunk, which descends in the posterior compartment deep to the soleus and between tibialis posterior and FHL. A nutrient artery enters the middle third to give endosteal supply; multiple segmental periosteal and muscular branches supply the periosteum and overlying musculature; and septocutaneous perforators pass along the posterior intermuscular septum to the skin, allowing harvest of a vascularised skin paddle for post-operative monitoring. This dual endosteal and periosteal supply is what keeps a transferred fibula living and lets it heal by primary union. Compartments and the approach. The leg has three compartments — anterior (extensor digitorum longus, extensor hallucis longus, tibialis anterior), lateral (peroneus longus and brevis), and posterior (soleus, gastrocnemius, tibialis posterior, FHL). The lateral approach works the intermuscular plane between the peroneals and the soleus/FHL. The nerves at risk are the common peroneal nerve, which wraps around the fibular neck proximally, and the superficial peroneal nerve, which exits the lateral compartment in the distal third. Femoral head osteonecrosis — staging and the role of FVFG. Success is closely correlated with the stage at operation; the procedure works before collapse and fails once the head has collapsed.

Key evidence. Vascularised fibular grafts achieve primary union in 70 to 90 percent of large defects. The Capanna technique — a vascularised fibula inside a massive structural allograft — provides immediate mechanical stability from the allograft and long-term biological viability from the fibula, significantly reducing the rate of stress fracture compared with FVFG alone. For femoral head AVN, FVFG reliably delays or prevents total hip arthroplasty in young patients with early-stage disease; head survival correlates with stage, and post-collapse heads (collapse greater than 2 mm) fail at high rates. Over 6 to 18 months the graft hypertrophies in response to loading (Wolff's law), which is why it is particularly suited to younger, active patients.