Bone Transport Using Mono-lateral External Fixator Combined With Debridement And Bone Graft In The Treating Of The Infected Bone Nonunion

Objective:The aim of this study was to evaluate the clinical and functional outcomes of infected nonunion of the long bone metaphysis with soft-tissue defects or sinus by internal bone transport with the hybrid mono-lateral external fixator.Method:We retrospectively reviewed 20 patients who underwent internal bone transport for infected nonunion in the long bone metaphysis.16 cases were open fractures,The other 4 cases were close fractures.Mean follow-up was 18 months.The results were evaluated by the classification of the Association for the Study and Application of the Method of Ilizarove(ASAMI) which divied into bone and functional categories.Results:18 patients got primary bone union,19 patients achieved infection being controlled,and 1 were bony ununion,1 got amputation.12 patients underwent cancellous bone grafting at docking sites(1 patients received two times).Bone results were 112 excellent and good,4 fair and 4 poor.And functional results were 11 excellent and good, 5 fair and 4 poor.The mean length of time in healing for all patients were 11 months. The mean length of regenerating bone were 5.8 cm.The main complication was pin infection.Conclusion:The long bone metaphysis infected nonunion can be successfully treated using the hybrid mono-lateral external fixtor combined with internal bone transport technique.The advantages of bone transport include good controlling for soft tissue infection,large bone defects can be treated with same bone diameter,limited donor-site morbility.Coating pins with hydroxyapatite increases the bone fixation and reduces the rate of pin infection and loosening during external fixation for distraction osteogenesis. And the distraction rate should be limited into 1mm/24h to decrease neurovascular complication..