Free fibula donor-site morbidity: clinical and biomechanical analysis

The aim of this study was the quantitative assessment of donor-site morbidity after fibula harvest. Ten patients were identified with a unilateral fibula harvesting and healthy contralateral side. The average follow-up time was 32.3 months. The study design included standardized questionnaire; morbidity point-evaluation system; orthopedic-biomechanical evaluation, including true ankle motion, clinical-functional American Orthopedic Foot and Ankle Society (AOFAS) hindfoot score, pedobarography, measurement of maximal voluntary isometric strength, and radiologic examination using an ankle osteoarthritis grading. Average donor-side morbidity score was low, with 2.6 points (range, 0 to 13). Average AOFAS hindfoot score was good, with 87.3 points (range, 74 to 100). Pedobarography showed significant decrease of the big toe pushup force. Isometric strength measurement showed significant reduction of the peroneus longus muscle. Discrete to mild medial ankle osteoarthritis was found in 70% of the cases. The overall donor-side morbidity was low, but an eversion torque deficit could initiate or support a progressive functional ankle instability and in long-term cause or accelerate a ligamentous secondary ankle osteoarthritis.