Experimental Study on Tissue Fluid Influenced by Antibiotic-Acrylic Bone Cement Composite / 대한정형외과학회잡지

ABSTRACT

Failure of total joint replacement is often due to infection. Many efforts have been made to reduce the rate of infection. The use of antibiotic-acrylic bone cement composites for the preventlon and treatment of infection after joint replacement surgery has been advocated. Early reports of clinical success using bone cement containing antibiotics are encouraging, but different results of antibacterial effect of antibiotic-acrylic bone cement were reported in vitro and in vivo studies. The purpose of this experiment is to determine the effectiveness of bone cement itself on bacterial growth, stability of antibiotics in cured bone cement, and whether antibiotic acrylic bone cement composites produce an effective antimicrobial concentration in tissue fluid of hip joint and if so, the duration of it. 30 rabbits were used as test animal 3 each for hemiarthroplasty and for hemiarthroplasty with the insertion of bone cement as control; 6 each for dicloxacillin, cephacetrile, gentamycin and amlkacin impregnated bone cements. Antibiotic activities were measured by disk diffusion method and tube dilution method using tissue fluid collected through tube inserted in the hip joint of the animals. The results were as follows 1. Bone cement itself does not have antibacterial effec on the growth of Staphyiococcus aureus and Escherichia coli. Antibiotic impregnated acrylic bone cements showed antibacterial effects which were stable for 3 weeks in vitro test. 2. After the insertion of antibiotic-acrylic bone cement composites, maximal concentrations of antibiotics in tissue fluid were measured at 1 hour. The concentration of antibiotics remained in tissue fluid at relatively high level for 2 days, and decreased abruptly there after. Inhibition zones in disk diffusion method could be measured until 3rd day in dicloxacillin group and 4th day in cephacetrile, gentamycin and amikacin group. No antibacterial effect could be measured in control groups. 3. On first postoperative day the concentrations of antibiotics in tissue fluid were measured as 64 mcg/ml in dicloxacillin group and 128 mcg/ml in cephacetrille, gentamycin and amikacin group. The antiblotic activities in tissue fluid could be measured for 6 days in dicloxacillin group and 7 days in cephacetrile, gentamycin and amikacin group using tube dilution method. No antibiotic activities were measured in tissue fluid of control groups. As a result of this study, it is proved that the concentration of antibiotics in tissue fluid of hip joint can be maintained above the level of minimal inhibitory concentration for about a week when antibiotic-acrylic bone cement composite is used in joint replacement arthroplasty. The impregnation of antibiotics in crylic bone cement is proved to be effective in the prevention of exogenous infection, especially in the protection of damaged tissue prone to infection postoperatively.