Evaluation of the ankle function following reconstruction of the donor defect with a split fibular bone after a vascularized fibular flap transfer

To validate the hypothesis that the reconstruction of the missing segment of the fibula using a redundant split fibular graft after a vascularized fibular flap transfer may have a better effect on ankle function. Of the 24 head and neck cancer patients who received a free fibula flap for mandible reconstruction, 14 patients underwent the conventional method of donor site closure, in which the redundant fibular bone was discarded (Group I). Ten patients underwent longitudinal osteotomy of the redundant non-vascularized fibular portion to bridge the donor site defect (Group II). Postoperative subjective satisfaction level was evaluated with a self-constructed questionnaire in 10 parameters (ambulation with assistance, ankle instability, ankle stiffness, muscle weakness, leg edema, foot numbness, ankle pain, other sites of pain besides the ankle, and restriction to run) and the 4 voluntary motions (dorsiflexion, plantar flexion, eversion, and inversion) of both ankles were measured using a CYBEX II dynamometer. The muscle peak torque of the donor leg was significantly lower at ankle plantar flexion (P = 0.002), eversion (P = 0.002), and inversion (P = 0.0002) in Group I as well as at dorsiflexion (P = 0.031), plantar flexion (P = 0.016), and inversion (P = 0.002) in Group II against the contralateral non-operated leg. The muscle power was significantly greater when performing ankle eversion (P = 0.049) in those who underwent split fibular bone reconstruction. There was no difference in the subjective satisfaction score between these two groups. The reconstruction of the donor site with a split fibular bone graft led only a slight improvement in ankle eversion.