Objective:To explore the effects of using AO micro-plate and allograft bone to treat the comminuted metacarpal and phalanx fractures with bone defects.Methods:From March 2004 to January 2008

we used micro-AO plate and allograft bone to treat 38 comminuted metacarpal and phalanx fractures with bone defect.The patients were allowed to begin flexion and extension of the injured joint on the fourth day after surgery.Results:24 in 30 patients healed

4 patients were infected and they healed finally by drainage and changed of the dressing:2 plates were exposed because of skin and soft tissue necrosis

then the wounds were closed with flaps.X-ray showed that the time of fracture healing was 6～12 weeks

with an average of 8 weeks.After following-up 6 months～3 years

according to the Chinese Medical Association of Hand Surgery Institute of hand function evaluation standards

the hands function was excellent in 22 patients

good in 5 patients

ordinary in 2 patients

poor in 1 patient

with the good rate of 90.Conclusion:Good hand function can be achieved by using AO mini-plate and allograft bone to treat the comminuted metacarpal and phalanx fractures with bone defects.