Utility of bone scanning in the postoperative assessment of fibula-free tissue transfers

Abstract

Objectives: The fibula osteocutaneous free flap has proven one of the most versatile and reliable flaps available for reconstruction of mandibular defects. Survival rates are exceedingly good with most centers reporting survival in >95% of cases. Viability of the bone is indirectly inferred by examination and visibility of the skin paddle. Occasionally, the skin paddle dies and the status of the bone is unknown. In these instances, one must ascertain the status of the bone in order to plan appropriately. We report on our experience with bone scanning in differentiating bone survival from bone death when the skin paddle has necrosed. Setting: Tertiary referral academic center Oregon Health & Science University. Methods: From 1998 to 2004, 130 fibula osteocutaneous free tissue transfers were undertaken. Results: In 7 of these, viability of the bone was questioned (5 skin paddle necrosis, 2 buried flap with no external monitor and a severe neck infection. Bone scanning was undertaken to help in operative planning. In 4 flaps, the bone paddle was felt to be alive on scan and confirmed intraoperatively. The skin paddle was debrided and replaced with a radial forearm free flap. Bone viability was confirmed at most recent follow-up. In 3 cases, the bone was confirmed to be nonviable by bone scan and confirmed by inspection intraoperatively. These cases were repaired with a second fibula free flap. Conclusion: Bone scanning is a useful investigation in cases where viability of the bone is in question. In flaps where the bone is buried or those in which the skin paddle has died, a positive bone scan will allow for planning of only soft tissue coverage, whereas a negative bone scan will imply a second bone flap.