Objective:To report the clinical outcome of repairing massive bone defects biologically in limbs by homeochronous using structural bone allografts with intramedullary vascularized fibular autografts. Methods: From January 2001 to December 2005

large bone defects in 19 patients （11 men and 8 women

aged 6 to 35 years） were repaired by structural bone allografts with intramedullary vascularized fibular autografts in the homeochronous period. The range of the length of bone defects was 11 to 25 cm （mean 17.6 cm）

length of vascularized free fibular was 15 to 29 cm （mean 19.2 cm）

length of massive bone allografts was 11 to 24 cm （mean 17.1 cm）. Location of massive bone defects was in humerus（n=1）

in femur（n=9） and in tibia（n=9）

respectively. Results: After 9 to 69 months （mean 38.2 months） follow-up

wounds of donor and recipient sites were healed inⅠstage

monitoring-flaps were alive

eject reaction of massive bone allografts were slight

no complications in donor limbs. Fifteen patients had the evidence of radiographic union 3 to 6 months after surgery

3 cases united 8 months later

and the remained one case of malignant synovioma in distal femur recurred and amputated the leg 2.5 months

postoperatively. Five patients had been removed internal fixation

complete bone unions were found one year postoperatively. None of massive bone allografts were absorbed or collapsed at last follow-up. Conclusion: The homeochronous usage of structural bone allograft with an intramedullary vascularized fibular autograft can biologically obtain a structure with the immediate mechanical strength of the allograft

a potential result of revascularization through the vascularized fibula

and accelerate bone union not only between fibular autograft and the host but also between massive bone allograft and the host.