[Effectiveness analysis of induced membrane technique in the treatment of infectious bone defect]

To evaluate the effectiveness of induced membrane technique in the treatment of infectious bone defect.

Thirty-six patients (37 bone lesions) with infectious bone defects were treated with induced membrane technique between January 2011 and June 2014. There were 28 males and 8 females with an average age of 36 years (range, 20-68 years). All bone defects were post-traumatic infectious bone defect. The bone defect was located at the tibia and fibula in 24 cases (25 bone lesions), at femurs in 6 cases (6 bone lesions), at ulnas and radii in 2 cases (2 bone lesions), at calcanei in 3 cases (3 bone lesions), and at clavicle in 1 case (1 bone lesion). The average time between onset and the treatment of induced membrane technique was 6.2 months (range, 0.5-36.0 months); 15 patients were acute infections (disease duration was less than 3 months). At the first stage, after the removal of internal fixator (applicable for the patients who had internal fixation), complete debridement of infection necrotic bone tissue and surrounding soft tissue was performed and the bone defects were filled with antibiotic-impregnated cement spacers. If the bone was unstable after debridement, external fixator or plaster could be used for stabilization. Patients received sensitive antibiotics postoperatively. At the second stage (usually 6-8 weeks later), the cement spacer were removed, with preservation of the induced membrane formed by the spacer, and filled the bone defect with autologous iliac bone graft within the membrane.

The hospitalization time after debridement was 17-30 days (mean, 22.2 days), and the hospitalization time after the second stage was 7-14 days (mean, 10 days). All the flaps healed uneventfully in 16 cases treated with local flap transposition or free flap grafting after debridement. One patient of femur fracture received Ilizarov treatment after recurrence of infection at 11 months after operation; 1 patient of distal femoral fracture received amputation after recurrence of infection at 1 month after operation; 1 patient of distal end of tibia and fibula fractures received ankle arthrodesis after repeated debridements due to the recurrence of infection; 1 patient of tibia and fibula fractures lost to follow-up. The other 32 patients (33 bone lesions) were followed up 1-5 years (mean, 2 years) without infection recurrence, and the infection control rate was 91.7% (33/36). All the patients had bony union, and the healing time was 4-12 months (mean, 7.5 months); no refracture occurred. One patient of femur bone defect had a lateral angulation of 15° and leg discrepancy of 1.5 cm. Superficial pin infection was observed in 7 cases and healed after intensive wound care and oral antibiotics. Adjacent joint function restriction were observed in 6 cases at last follow-up.

Induced membrane technique is a simple and reliable technique for the treatment of infectious bone defect. The technique is not limited to the size of the bone defect and the effectiveness is satisfactory.