Prevention of pin tract infections in external fixation by an electric current

Prevention of pin tract infections in external fixation by an electric current

Schrijvers, J.C.

Plettenburg, D.H. (mentor)
Valstar, E.R. (mentor)
Struik, T. (mentor)
Mastbergen, S. (mentor)
Lafeber, F.P.J.G. (mentor)

Mechanical, Maritime and Materials Engineering

BioMechanical Engineering

Biomechanical Design

2015-12-11

Pin tract infection is a prevalent complication in treatments with external fixation. This study focused on the external fixation utilized for the knee joint distraction treatment. In a previous study initiated by the UMC Utrecht 85% of the patients got at least one pin tract infection during this treatment. A pin tract infection is caused by bacteria (mainly staphylococci) that form a biofilm on the surface of the external fixation pin. Currently, antibiotics are used to treat pin tract infections. High doses of antibiotics are needed to resolve a biofilm. Prevention of biofilm development is necessary to minimize the antibiotic use. The literature suggested that a small electric current could have an influence on the biofilm formation and therewith the chance of infection. The first aim of this study was to investigate the effect of three different current heights (20, 100 and 500 µA) on the bacteria on the surface of external fixation pins. The secondary aim was to develop a wearable device for the knee joint distraction treatment that could deliver this current to the pin tract. Results from the experiments showed that: it was possible to form a starting biofilm in 24 hours with Staphylococcus aureus on an external fixation pin and an electric current decreases the amount of viable bacteria on the pin and in the fluid surrounding it. The amplitude of the current had an influence on the extent to which the bacteria were killed. The ratio of viable bacteria on the surface of the anode pins was: 1 out of 18 (20 µA), 1 out of 200 (100 µA) and 1 out of 11 (500 µA). On the surface of the cathode pins this was: the same as control (20 µA), 1 out of 12 (100 µA) and zero (500 µA). In the fluids the ratio of viable bacteria were: 1 out of 9 (20 µA), 1 out of 10.000 (100 µA) and 1 out of 100.000 (500 µA). A different process was observed on the anode pins than on the cathode pins. A current of 500 µA was used in the developed prototypes of a wearable device. One of the two prototypes tested in-vitro, successfully killed bacteria and prevented biofilm formation on the surface of the external fixator pins. The developed wearable device has the potential to make pin tract infection a rare complication during the use of external fixation for the knee joint distraction treatment.

pin
tract
infection
prevention
external fixation
electricity

http://resolver.tudelft.nl/uuid:3d062f00-23bf-4fb0-aaaf-c6afb69654d7

Student theses

master thesis

(c) 2015 Schrijvers, J.C.