Highly Adhesive Antimicrobial Coatings for External Fixation Devices

Area of Science:

• Orthopedic Surgery
• Biomaterials Science
• Infectious Disease Prevention

Background:

• Percutaneous pinning techniques disrupt the skin barrier, leading to pin site infections, with rates up to 100% after external fixation.
• Pin site infections can cause loosening, increased pain, and more severe complications like osteomyelitis, necessitating effective prevention strategies.
• Current antimicrobial coatings for orthopedic implants often suffer from poor adhesion, detaching under shear forces during implantation.

Purpose of the Study:

• To develop highly adhesive, drug-eluting coatings for orthopedic pins to prevent pin site infections.
• To create novel gel coatings that maintain antimicrobial efficacy after implantation under shear stress.
• To reduce the morbidity and cost associated with implant-associated infections in orthopedic procedures.

Main Methods:

• Development of two gel coating types: synthetic poly-glycidyl methacrylate-based and natural chitosan-based.
• Testing coating adhesion to pins under strong shear forces, simulating implantation conditions.
• Incorporation of antibiotics into the gel coatings and evaluation of antimicrobial efficacy on bone-implanted K-wires.

Main Results:

• Both synthetic and natural gel coatings demonstrated strong adhesion to pins, withstanding significant shear forces without damage.
• Antibiotic-loaded K-wires with the developed coatings retained antimicrobial efficacy after implantation and removal from bone.
• The coatings proved robust, suggesting potential for improved antimicrobial delivery in orthopedic implants.

Conclusions:

• Novel synthetic and chitosan-based gel coatings offer a promising solution for enhancing the antimicrobial efficacy and durability of orthopedic pins.
• These highly adhesive coatings can effectively deliver antibiotics and resist dislodgement, addressing a key limitation of current technologies.
• The developed coating technology has the potential to significantly reduce the incidence and impact of pin site infections in orthopedic surgery.