Strategic considerations on the configuration of free flaps and their vascular pedicles combined with Ilizarov distraction in the lower extremity.

For the injury of the lower leg associated with both bone and soft-tissue defect, the combined free flap and the Ilizarov distraction method were described as a useful treatment modality. During the procedure of distraction, however, revisions were frequently needed to change the pin position or to change the flap configuration. In case of flap ischemia, distraction should be delayed or abandoned. Then, a vascularized bone transfer might be necessary. To avoid these complications and achieve safe distraction, the configuration of the flap with its vascular pedicle should be carefully planned in terms of the future bony lengthening procedures and the concomitant soft-tissue changes of the lower leg. According to the response of local tissue to the distraction process, the lower limb can be divided into four compartments (active mobile, passive mobile, receptive, and restrictive). The configuration of the transferred free flap with its vascular pedicle can be classified into five types. To minimize the undue forces to the vascular pedicle and reduce the possibility of vascular compromise, the transferred free flap should have the configuration that its vascular pedicle lies in the territory of the mobile compartment. In performing free-tissue transfer combined with the Ilizarov method in the lower extremity, the configuration of the flap with its vascular pedicle should be carefully planned, and the characteristics of lower leg tissue should be kept in mind during the distraction.