Hypertrophy after free vascularized fibular transfer to the lower limb

This study included 25 patients with lower limb tumors who had reconstruction by vascularized fibula osteoseptocutaneous flap performed at least 24 months before the end of the study. Hypertrophy of the transplanted fibula was estimated on serial radiographs by a modification of the formula of De Boer and Wood (J Bone Joint Surg [Br] 71:374-378, 1989). A significant graft was observed in 90% of the patients at an average follow-up of 27 months (range, 30-200%). The time to graft union (start of partial weight-bearing) positively correlated with the time to significant graft hypertrophy (r = 0.9, P < 0.01). The final amount of graft hypertrophy was affected by the age of the patient (P < 0.01) and the length of follow-up (P < 0.05). Graft hypertrophy progressed at an average rate of 3.3% per month (range, 2.3-4.9%) until the end of the 30th month; thereafter, little or no increase in graft hypertrophy was observed. The rate of graft hypertrophy showed two significant peaks at 6-12 months (P < 0.001) and at 18-24 months (P < 0.05). Patients younger than age 20 years showed faster hypertrophy, with a peak at the 12th month. Hypertrophy progressed faster in patients who received chemotherapy until the 12th month, and then declined sharply compared to those who did not receive chemotherapy.