Abstract
Purpose
Gustilo type III open fractures are associated with high infection rates in spite of instituting a standard of care (SOC) consisting of intravenous antibiotics, irrigation and debridement (I&D), and delayed wound closure. Locally-delivered antibiotic has been proven to assist in reducing infection in open fractures. The aims of this study are to determine the effectiveness and safety of a new implantable and biodegradable antibacterial product1 in preventing bacterial infections and initiating bone growth in open fractures.
Methods
The osteoconductive antibacterial BonyPidTM used is a synthetic bone void filler (comprised of ≤1 mm β-tricalcium phosphate granules) coated by a thin layer (≤20 µm) of PolyPid nanotechnology formulation−. Upon implantation, the coating releases doxycycline at a constant rate for a predetermined period of 30 days. One BonyPidTM vial of 10 grams contains 65 mg of formulated doxycycline. After approval, sixteen subjects with Gustilo type III open tibia fractures, were implanted with the BonyPidTM immediately on the first surgical intervention (I&D), followed by external fixation. Patients had periodic laboratory, bacteriology and radiology follow-up.
Results
Six months results showed that no infection developed and only one BonyPidTM implantation was needed with no subsequent I&D, in the target tibia fracture. Immediate soft wound closure was done in 6/16 subjects following implantation. Out of 10 remaining subjects, 3 needed soleus muscle transfer-skin grafting and 7 required delayed primary closure; by skin grafting (5) or suturing (2). Early callus formation was seen at 8–12 weeks post-surgery, followed by bone healing seen from 16 weeks onwards. Safety of implantation was remarkable, with only one deep infection at a fibular open fracture without BonyPidTM implantation. One BonyPidTM -related adverse event caused delay in skin healing due to excessive granules in the superficial soft tissues.
Conclusion
BonyPidTM is effective in reducing bone infection and promoting early callus formation, resulting in early bone healing. BonyPidTM is safe for immediate implantation into contaminated/infected severe open-bone fractures. Results support that one month release of doxycycline in a controlled manner provides an effective way for treating open fractures. This new local antibiotic delivery system is applicable in unmet medical situations associated with localised infections.
