Induced membrane technique using an equal portion of autologous cancellous bone and β-tricalcium phosphate provided a successful outcome for osteomyelitis in large part of the femoral diaphysis - Case report

BACKGROUND: No report has yet described good prognosis following the induced membrane technique (IMT) for bone defects over 200 mm. CASE PRESENTATION: A 46-year-old male developed osteomyelitis over a large portion of the right femoral diaphysis, which had an unknown infection route, and subtrochanteric fracture during the waiting period of the planed IMT. Around 3 days after the pathological fracture, the first stage was performed. Aggressive debridement resulted in large segmental bone defect, which was treated with internal fixation using intramedullary nailing and insertion of an antibiotic-impregnated polymethylmethacrylate (PMMA) spacer. Postoperative radiographs showed a radiographic apparent bone gap of 221 mm. A subsequent culture of the debrided bone test identified Corynebacterium as the causative organism, with blood examination indicating normal C-reactive protein, white blood cell count, and erythrocyte sedimentation rate following 4 weeks of intravenous antibiotic administration. Around 7 weeks after the first stage, the second stage was initiated. After removing the PMMA spacer, grafting was performed by filling the bone defect with a combination of autologous cancellous bone harvested from the posterior iliac crest and β-tricalcium phosphate (β-TCP), which were mixed in approximately equal proportions. Routine postoperative radiographs confirmed a sequential healing process and callus formation in three out of four cortices 3 years after surgery. CONCLUSIONS: In the present case, IMT was able to successfully treat the osteomyelitis-induced large segmental bone defect of the femoral shaft exceeding 200 mm. Had autologous cancellous bone alone been applied during the second stage, the possible amount of bone defect covered by the IMT would have been limited. However, this limitation can be addressed by applying β-TCP. Further expansion of IMT indications may help address challenges in the treatment of extensive bone defects.