Infection is one of the main reasons for failure of orthopedic implants. Antibacterial coatings may prevent bacterial adhesion and biofilm formation, according to various preclinical studies. The aim of the present study is to report the first clinical trial on an antibiotic loaded fast-resorbable hydrogel coating (Defensive Antibacterial Coating, DAC) to prevent surgical site infection, in patients undergoing internal osteosynthesis for closed fractures.

In this multicenter randomized controlled prospective study, a total of 256 patients in five European orthopedic centers who were scheduled to receive osteosynthesis for a closed fracture were randomly assigned to receive antibiotic-loaded DAC or to a control group (without coating). Pre and postoperative assessment of laboratory tests, wound healing, clinical scores and X-rays were performed at fixed time intervals.

Overall, 253 patients were available with a mean follow-up of 18.1±4.5 months (range: 12–30). On average, wound healing, clinical scores, laboratory tests and radiographic findings did not show any significant difference between the two groups. Six surgical site infections (4.6%) were observed in the control group compared to none in the treated group (P.03). No local or systemic side effects related to the DAC hydrogel product were observed and no detectable interference with bone healing was noted.

This is the first clinical trial reporting on the efficacy and safety of DAC coating for internal osteosynthesis. Concerning efficacy, this study shows that the studied antibiotic-loaded hydrogel coating is able to significantly reduce early surgical site infection after osteosynthesis, at an average 18-month follow-up. This finding is in agreement with earlier in vivo studies and with the results of a multicenter clinical trial on the use of DAC coating in total hip and knee cementless or hybrid total joint replacement.

The use of a fast-resorbable antibiotic-loaded hydrogel implant coating provides a reduced rate of postsurgical site infections after internal osteosynthesis for closed fractures, without any detectable adverse event or side-effects. Ease of use, versatility and lack of side effects may open the way to an affordable wide application of antibacterial implants protection for large scale applications.