Minimizing risk to the vascularity of the osteotomized fibula: a technical note

Abstract

The fibula free flap may be osseous or osteocutaneous and is supplied by the the distal end of the fibula leading to a compromise in the periosteal supply to this the senior author for at least 10 years with a success rate for osteotomized bone peroneal artery and vein. The lateral approach which is universally adopted for raising the flap was first described by GILBERT in 1979. HIDALGO first described the utilization of the free fibula for mandibular reconstruction in 1989. We describe a minor modification to this technique which we believe reduces the risk to the vascularity of the osteotomized fibula, particularly the distal segment. Although there are medullary branches of the peroneal artery they are rarely of significance in osteotomized fibula flaps and the principal blood supply to the osteotomized fibula is via small paraosteal vessels, which supply the muscles and periosteum that attach along its length. The viability of the bone segments depends on maintaining the continuity of these small vessels arising from the peroneal artery. The standard approach when raising a fibula free flap is to osteotomize the fibula proximally and distally and, after dividing the interosseous fascia, to mobilize the whole segment laterally in order to help identify and dissect out the pedicle. In our experience, this is the moment when the pedicle may be pulled away from area. This is most likely to be a problem when the required segment of bone is osteotomized further one or more times to adapt to a complex shape, with the likelihood of a relatively small distal fragment. Maintaining the attachment of the peroneal pedicle to the distal fragment can prove problematical. We have found that if a small segment of bone is removed distally early in the procedure before the interosseous fascia has been cut, it allows the surgeon to localize the peroneal artery and vein easily (Fig. 1). The pedicle is then ligated and divided prior to mobilizing the main segment of bone laterally. This maneuver enables the surgeon to ensure that the pedicle is not inadvertently pulled away or detached from the bone distally during mobilization, and it also helps the surgeon to safely incise the posterior tibialis muscle without damaging the pedicle. The risk to the vascularity of the small osteotomized distal segments of bone can thus be minimized. Although we have no substantive data to prove our thesis that this technique adds safety to the traditional approach, it has been used by transfer of more than 95%. Personal preferences will always influence the techniques used by individual surgeons, but we report this variation in bone harvest as a possible means of maintaining the vascularity to smaller distal bone segments at risk.