Artificially contaminated open tibial fractures: Therapy with cloxacillin sodium

Abstract

Three methods of treatment by Cloxacillin were applied for the prevention of deep infection of bones after artificial contamination of fractured rat tibia, with Staphylococcus aureus. Thus, combined intramedullary and parenteral therapy was compared with intramedullary administration only and parenteral therapy only. Intramedullary injection of 15 mg Cloxacillin (dissolved in water) during surgical management of the fracture and postoperative parenteral treatment with the same antibiotic in a dose of 50 mg/kg/day over 14 days prevented the development of staphylococcal infection in all animals (n=21). Cloxacillin parenteral treatment only achieved a therapeutical effect after 42 days of application in a dose of 50 mg/kg. A single, intramedullary injection of 15 mg aqueous solution of Cloxacillin failed to prevent completely the staphylococcal infection. This therapy was relatively successful till postoperative day 28, namely, there were only 16.6% of positive results for S.aureus in relation to 40% on day 42 after the surgery. Gross, radiological and histological changes of the operated tibia of rats were correlated to the effects of the therapy applied. The results of our studies suggest that, in open tibial fractures, parenteral therapy together with intramedullary administration of antibiotics may prevent the development of infection and shorten the parenteral therapy by a direct effect on the contaminated injury during the first few postoperative days.

Na modelu arterficijalnog preloma potkolenice pacova i posle arteficijalne kontaminacije sa Staphylococcus aureus-om, u cilju sprečavanja duboke infekcije kostiju primenjene su tri metode lečenja antibiotikom Kloksacilinom: 1 kombinovana intramedularna I parenteralna terapija koja je poređena sa: 2. samo intramedularnom i 3. samo parenteralnom terapijom Kloksacilinom. Intramedularna inokulacija 15 mg Kloksacilina (rastvorenog u vodi) u toku hirurškog zbrinjavanja preloma i postoperativnog parenteralnog lečenja istim antibiotikom u dozi od 50 mg/kg dnevno u toku 14 dana, sprečila je nastajanje stafilokokne infekcije kod svih životinja (n=21). Samo parenteralnim lečenjem Kloksacilinom postignut je terapijski efekat posle 42 dana davanja u dozi od 50 mg/kg. Jednokratnom, intramedularnom aplikacijom 15 mg vodenog rastvora Kloksacilina nije u potpunosti sprečena stafilokokna infekcija. Ova terapija bila je uspešnija do 28-og postoperativnog dana (16,6% pozitivnih nalaza S.aureusa, u odnosu na 40%, 42-og dana posle operacije). Makroksopski, radiološki i histološki promene na operisanoj potkolenici pacova bile su u skladu sa efektima primenjene terapije. Rezultati naših istraživanja ukazuju da kod otvorenih preloma potkolenice uz parenteralnu terapiju, intramedularna aplikacija antibiotika, zbog direktnog delovanja u kontaminiranoj povredi, u prvim postoperativnim danima sprečava razvijanje infekcije i skraćuje period parenteralne terapije.