The role of biofilm formation in percutaneous Kirschner-wire fixation of radial fractures.

This study examines the formation of bacterial biofilms on percutaneous wires used for fracture fixation. Twelve control (clinically uninfected) wires and ten infected wires were collected and examined using broth culture and scanning electron microscopy. Three of the 12 control wires grew Staphylococcus spp. with very low bacterial counts in their percutaneous portions. In the clinically infected wires, six wires in four subjects had positive cultures in their percutaneous portions and four of these also had positive cultures in their deep portions with much higher bacterial counts than the controls. In two patients (four wires) treated with antibiotics, cultures were negative except for the percutaneous portion of one wire. Scanning electron microscopy did not reveal bacterial biofilm formation, but biological deposit without bacteria was noted on most wires. During the 6 weeks of fracture fixation, some bacterial colonization of wires occurred, but bacteria did not form biofilms which may increase bacterial resistance to systemic antibiotics, cause implant loosening and act as a source of late infection.