INTRAOPERATIVE DISINFECTION OF BONE PROSTHESES

The formation of bacterial biofilms in bone implants, such as prosthetic knee implants, is a post-surgical complication that leads to chronic infections, as well as the protection of bacterial colonies from antibiotics. Biofilms are generated mainly by the adhesion of microorganisms to the metal surfaces of prostheses, and contain enzymes that trap antimicrobial agents, which decreases the penetration of antibiotics, reducing their effectiveness. In this invention, a device for intraoperative use has been developed that performs an electro-disinfection process to reduce biofilm or bacterial infections in knee prostheses. The new system provides a terminal with an electrode array that is placed on the external surface of the prosthesis to be treated and a control system that controls the sequence and the amount of energy applied through each of the electrodes. The device is used only during the time of the surgical intervention.

Competitive advantages

The treatment of bone prosthesis infections is complex, long and expensive. Traditionally, this involves washing and replacing the mobile components in recent implant infections (three to six weeks after surgery), using antibiotic-impregnated cements, and intraoperative irrigation. However, biofilm can remain in a state of hibernation for long periods of time, making it significantly more difficult to detect using traditional techniques. After the aforementioned initial period after surgery, treatment of infections usually requires complete replacement of the implant in a single surgery or, alternatively, a first replacement with a temporary component which, after a minimum period of six weeks, is replaced in a second operation with a permanent implant. The first method has a success rate of between 50-55%, while the second increases to 70-90%. However, in any case these methods have an enormous physical and psychological cost for the patient, as well as a high economic cost, which in the case of knee prostheses is estimated worldwide at around twenty billion dollars, corresponding to the infection in 1%-2% of cases, which means approximately three hundred thousand infected prostheses per year. Additionally, it should be noted that a significant number of infections are not solved with these methods, which can lead to amputation or even death of the patient. The most recent studies indicate that five-year mortality after a prosthetic infection rises to 25.9%, compared to 12.0% in patients without infection. The developed system does not require the use of special prostheses and is used only during an intervention for disinfection. Other related systems based on bioelectric effects use modified prostheses or implanted electrodes.

Uses and applications

The present invention is framed in the medical sector and, more specifically, in orthopedic surgery. Its application is mainly focused on the prevention and intraoperative elimination of infections in knee prostheses, although not limited to other types of prostheses or applications, through the application of low-power electric currents. Therefore, the potential market of interest is manufacturers of medical equipment and knee prostheses.