Microsurgery: Transplantation and Replantation by Harry J. Buncke, MD, et al.
  Table of Contents / Chapter 16:
Fibular Free Flaps
 
  The patient is placed in the decubitus position with the donor side up and the knee flexed. The fibular head and the lateral malleolus are palpated and their locations marked. An attempt should be made to palpate the fibula between these points and mark the axis of the fibula. The common peroneal nerve is palpable as it winds around the fibular neck, and its location should be noted. The length of the fibula needed should be determined and the osteotomy planned, allowing for an extra 2 cm at each end. The proximal osteotomy should be planned at least 8 cm distal to the fibular head. This avoids injury to the common peroneal nerve, yet places the osteotomy proximal to the fibular vascular pedicle (peroneal vessels). The distal osteotomy should preserve the distal fourth of the fibula to maintain ankle stability. The skin incision is marked and the leg exsanguinated with an Esmarch bandage, and the tourniquet is inflated to 300 mm of mercury so that dissection is carried out in a bloodless field.

Variations in the incision are made according to the type of flap desired, e.g., osteomyocutaneous, osteocutaneous, or osseous only. For the myo-osseous flap, the incision is made along the posterior border of fibula. The peroneal muscles, along with the common peroneal nerve, are retracted anteriorly, and the soleus is retracted posteriorly, thus exposing the fascia between them, which is then incised. This plane is developed, maintaining a 5 mm to 10 mm cuff of muscle around the fibula to preserve its blood supply. Preservation of the cuff is particularly important along the posteromedial aspects of the fibula because this is where the main nutrient vessels enter. Identify, ligate, and divide the peroneal artery that emerges from the lower border of the flexor hallucis longus at the distal end of the fibula. It is often easier to do the distal fibular osteotomy first because this provides easier access to the distal peroneal vessels.

 

The length of the fibula required is checked, and 2 cm are added to each end to allow intramedullary fitting of the fibular bone flap. Cuts of periosteum at each end of the osteotomy of the fibular flap are sometimes preserved and later wrapped around the osteosynthesis to enhance healing. It is important to divide the distal fibula at least 5 cm proximal to the lateral malleolus to preserve key ankle mortise ligaments and the proximal attachments of the peroneal muscles. Place a right-angle clamp medial to the fibula at the osteotomy site and pass a Gigli blade around the fibula to divide it. Malleable retractors are useful in protecting soft tissues from the saw blade during this procedure. Outward traction is placed on the fibula, and the interosseous membrane is divided. The distal end of the peroneal vessels is identified, ligated, and divided, if this has not already been done. Care is taken to identify and preserve the proximal end of the peroneal vessels that lie posteromedial to the fibula.

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