Infections represent a devastating complication in orthopedic and traumatological surgery, with high rates of morbidity and mortality. An early intervention is essential, and it includes a radical surgical approach supported by targeted intravenous antimicrobial therapy. The availability of parenteral antibiotics at the site of infection is usually poor, so it is crucial to maximize local antibiotic concentration using local carriers. Our work aims to describe the uses of one of these systems, Stimulan®, for the management and prevention of infections at our Institution. Analysing the reported uses of Stimulan®, we identified two major groups: bone substitute and carrier material for local antibiotic therapy. The first group includes its application as a filler of dead spaces within bone or soft tissues resulting from traumatic events or previous surgery. The second group comprehends the use of Stimulan® for the treatment of osteomyelitis, post-traumatic septic events, periprosthetic joint infections, arthroplasty revision surgery, prevention in open fractures, surgery of the diabetic foot, oncological surgery and for all those patients susceptible to a high risk of infection. We used Stimulan® in several complex clinical situations: in PJIs, in DAPRI procedure and both during the first and the second stage of a 2-stage revision surgery; furthermore, we started to exploit this antibiotic carrier also in prophylaxis of surgical site infections, as it happens in open fractures, and when a surgical site remediation is required, like in osteomyelitis following ORIF. Stimulan® is an extremely versatile and polyhedric material, available in the form of beads or paste, and can be mixed to a very broad range of antibiotics to better adapt to different bacteria and their antibiograms, and to surgeon's needs. These properties make it a very useful adjuvant for the management of complex cases of infection, and for their prevention, as well.
Objective: Bone marrow stromal cells (BMSC) represent an interesting target for novel strategies in the gene and cell therapy of skeletal pathologies, involving BMSC in vitro expansion/transfection and reinfusion. Materials and Methods: Stromal cells were obtained from healthy donors. For the first 2 weeks, culture medium was supplemented only with human recombinant fibroblast growth factor 2 (FGF-2) to promote cell proliferation and maintain cells in a more immature state. Confluent cultures were detached with trypsin-EDTA. Cells were replated for the in vitro differentiation experiments and for determination of BMSC growth kinetics. Cultures were stimulated with appropriate inductive media and the chondro-/osteo-/adipo-diferentiations were tested by staining with alizarin red, alcian blue, Sudan black and by immunostaining for osteocalcina or collagen II. Results: After the first passage, BMSC had a markedly diminish proliferation rate and gradually lost their multiple differentiation potential. Their bone-forming efficiency in vivo was reduced by about 36 times at first confluence as compared to fresh bone marrow. Conclusion: Culture expansion causes BMSC gradually to lose their early progenitor properties. Both the duration and the conditions of culture could be crucial to successful clinical use of these cells and must be considered when designing novel therapeutic strategies involving stromal mesenchymal progenitor manipulation and reinfusion. There are numerous potential applications of this novel strategy, for example: reconstruction of extensive long-bone defects, osteochondral defect repair, treatment of bone cyst, bioactivable scaffolds, etc.
