Fig. 1

Schematic representation of the timeline and procedures involved in the empty defect and IMT approach. In the timeline (upper panel) the different stages of the surgery of the two groups, empty defect (Group 1) and IMT (Group 2) are represented. In Group 2.1, four additional animals (n = 6 + 4) were added to evaluate early membrane development at 3 weeks. The timeline of the study defines t = 0 as the time point when surgical interventions cease, and 10 weeks bone healing (blue box) starts. The box with the up and down arrow heads indicates the revision surgery where the polymethylmethacrylate (PMMA) spacer is removed and the bone substitute based on β-tricalcium phosphate is inserted. Systemic antibiotics (green arrow) = rifampicin 2 × 40 mg/kg and levofloxacin 2 × 30 mg/kg. The images below (AF) show the different stages of the surgery in the IMT group in case of infection. (A) First, the osteotomy is created, and the bone is infected with S. aureus. (B) After 4 weeks the wound is opened, visibly infected and necrotic tissue is removed, and (C) a 5 mm defect is created. (D) The defect is filled with a 5 mm PMMA spacer. (E) After 3 weeks an induced membrane has formed over the PMMA spacer. The spacer is removed, and (F) a bone graft substitute is inserted in the defect