Management of Infected Bone Defects of the Lower Extremities by Three-Stage Induced Membrane Technique

BACKGROUND Infected bone defects are therapeutic challenges. Although the induced membrane technique has been used for this problem, there is a 3% to 20.7% failure to eradicate infection, and there have been few reports about its use in tuberculous infection. We present our three-stage induced membrane technique (TSIMT) for treating infected bone defects of the lower extremity. MATERIAL AND METHODS Forty-one adult patients with infected bone defects of the lower extremities treated by TSIMT were included in a retrospective case-series study between January 2013 and June 2018. The clinical, imaging and laboratory assessment outcomes were analyzed. RESULTS In the first stage, 3 patients had ankle tuberculous bone defects and 17 patients underwent 2-4 debridements. In the second stage, the average bone defect was 6.0 cm; 1 patient needed an anterolateral thigh flap to cover the wound. In the third stage, 10 patients underwent autograft mixed allograft, and 18 cases used internal fixation. The mean follow-up period was 23.3 months. All patients achieved bone union and clinical eradication of infection. Changes in Lower Extremity Functional Scale (LEFS) scores after 1 year of TSIMT and bone union time are associated with advanced age, longer duration of infected bone defects, active smoking, and external fixation (p<0.05), but are not dependent on bone defect size, debridement times, type of bone graft, or spacer-placing time (p>0.05). CONCLUSIONS TSIMT is effective in treating infected bone defects of the lower extremities. Advanced age, longer duration of infected bone defects, active smoking, and external fixation adversely affect bone union and recovery of infected extremities in a limited time span.