Donor-Site Morbidity after Osteocutaneous Free Fibula Transfer: Longitudinal Analysis of Stair Climbing Asymmetry and Functional Outcome

The autologous vascularised free fibula flap is currently considered the best option for facial reconstruction after oncological surgery, but its donor-site morbidity has not been fully examined. The purpose was to evaluate donor-site changes in temporal and spatial kinematic gait parameters during stair climbing, as well as the gait symmetry. Fourteen patients (48 +/- 16 years) were evaluated before and six months after harvest of a vascularised free fibula flap. Temporal gait variables for both the ascent and descent phases did not change after surgery (2-way ANOVA, p > 0.05). During stair ascent, ankle flexion (healthy side, increased; donor side, reduced; low effect size) had a significant time x side interaction. During stair descent, hip flexion was significantly larger on the donor side (medium effect size). Significant time x side interactions were observed for ankle inversion (healthy side, reduced; donor side, increased; and low effect size) and knee flexion (healthy side, increased; donor side, unchanged; and low effect size). Medium effect sizes were found for hip flexion side differences (significant). No relevant spatio-temporal nor kinematic asymmetry emerged apart from ankle joint kinematics. Overall, only the side effect of hip flexion during descent was both statistically significant and practically meaningful. Considering the slight modifications of the gait variables, no major functional limitations were found following vascularised free fibula flap reconstruction during stair climbing and descent.