Blood supply to osteocutaneous free fibula flap and peroneus longus muscle: prospective anatomic study and clinical applications.

From January of 1998 to December of 1999, a total of 24 fibula free flaps in 24 patients were evaluated in a prospective clinical study. Once the perforators were identified, they were dissected toward the parent vessel and labeled according to type. The soleus and flexor hallucis longus muscles of the fibula were dissected, and the proximal part of the pedicle was reached. Subsequently, the configuration of all muscular branches to the peroneus muscle was studied. The types of skin perforators of the peroneal artery were noted as septocutaneous, musculocutaneous, or septomusculocutaneous. A total of 86 perforators were identified in 24 legs. The average number of perforators per leg was 3.58 +/- 0.71. Among them, 22 were musculocutaneous, 31 were septomusculocutaneous, and were 33 septocutaneous. The septocutaneous branches were significantly more distal than the musculocutaneous and septomusculocutaneous perforators. Eight perforators were identified 25 cm distal from the fibular head and six were identified at 15 cm. Five perforators were then identified at each distance of 8, 12, 19, and 22 cm distal from the fibular head. The total number of muscular branches to the peroneus longus was 62, with an average of 2.58 +/- 0.45. Most muscular branches were found between 8 and 16 cm distal to the fibular head. Nine branches were identified at 13 cm distal to the fibular head, eight at 9 cm, and seven at 12 cm. The number of dominant branches with the largest diameter was seven at 13 cm distal from the fibular head, five at 12 cm, five at 16 cm, and two at 11 cm. In summary, when designing an osteocutaneous free fibula flap 10 to 20 cm from the fibular head, it is recommended that a soleus and flexor hallucis longus muscle cuff be included to incorporate these perforators. In contrast, when designing a flap 20 to 30 cm from the fibular head, it is possible to elevate the flap without incorporating the soleus or flexor hallucis muscles.