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Osteomyelitis was induced in the radius in 77 rabbits and confirmed by histological examination and culture. At 4 weeks, the wounds were debrided and the animals were treated with (a) fatty acid dimer-sebacic acid beads (a bioerodable composite) impregnated with 20% or (b) 10% gentamicin sulfate, (c) placebo beads and intramuscular gentamicin sulfate, (d) placebo beads alone, or (e) debridement only. After 4 weeks, eradication of infection was determined by histological examination and culture. Osteomyelitis was eradicated in 93% of the animals treated with the beads and 20% gentamicin, in 67% of those treated with the beads and 10% gentamicin, in 25% of those treated with placebo beads and intramuscular gentamicin, in 7% of those treated with placebo beads alone, and in 12.5% of those treated with debridement only (p values from < 0.001 to 0.02). Fatty acid dimer-sebacic acid beads with gentamicin were then implanted in noninfected rabbits, and gentamicin sulfate concentrations in bone, serum, urine, and wound exudate were measured. Gentamicin sulfate was detectable in bone for as long as 8 weeks after implantation. Levels as high as 4,746 micrograms/ml were present in the wound exudate for the first 7 days. Levels in the serum peaked at 1.03 micrograms/ml. Urine levels peaked at 135 micrograms/ml.

A multicenter study of infected total knee and total hip arthroplasties was conducted from 1985 until 1990. Twenty-eight patients (22 total hip arthroplasties and six total knee arthroplasties) who had periprosthetic infections were treated according to a prospective, randomized protocol. After initial debridement for their infections, patients were randomized into one of the two following groups: Group I, debridement and the implantation of gentamicin-polymethylmethacrylate (PMMA) beads; and Group 2, debridement and conventional parenteral systemic antibiotic therapy. After initial treatment, the patients were then scheduled for a delayed reconstruction total joint arthroplasty. Of the 28 patients, 25 subsequently had delayed total arthroplasty, and if acrylic bone cement was used for fixation at the time of reimplantation, antibiotics were not added to the cement. The average follow-up period was three years (range, six months to 5.6 years). Infection recurred in two patients treated by debridement and the implantation of gentamicin-PMMA beads (15%) and in four patients treated with debridement and conventional systemic antibiotic therapy (30%). All recurrences occurred in patients who had infected total hip arthroplasties; none occurred in patients with total knee arthroplasties. The conditions that were common in patients with recurrent infection were (1) multiple previous surgeries, (2) host compromise and malnutrition, (3) extensive infection, and (4) inadequate debridement. The recurrence of infection was not statistically significantly more common in either treatment group. The outcome of treatment in patients with infected total joint arthroplasties using debridement, gentamicin-PMMA bead implantation,and a two-stage delayed reconstruction was similar to that of patients treated with debridement combined with conventional parenteral systemic arthroplasty and two-stage reconstruction.

These data do not prove a statistical superiority of conventional antibiotics or Septopal in the treatment of chronic osteomyelitis. This result, however, is complicated by the biased data set represented by the combined treatment. The data do suggest that cost of treatment is considerably less in patients who are treated with local antibiotics (i.e., Septopal) alone. The rate of adverse experiences was directly related to the use of parenteral antibiotics, with higher rates of adverse experiences in the conventional and combined treatment groups. Furthermore, the Cierny-Mader Physiologic Class had the best correlation with outcome, suggesting that host factors are probably of critical importance in inducing remission of chronic osteomyelitis. This protocol was not designed to test the role of debridement in the treatment of osteomyelitis: it was assumed that debridement would be the same in both groups. It is the investigators' strong opinion, however, that adequacy of debridement was an important determinant in quiescence or recurrence in the study patients. Similarly, there was no strict control for adequacy of soft-tissue coverage provided by local or distant tissue transfer. Again, the investigators believe that adequacy, including viability and durability, of soft-tissue covering was an important determinant for the end result in these patients. Other covariants such as smoking, history, nutritional status, and other measures of general health will be added to this model when data are available. This analysis will allow definition of the appropriate clinical situations in which use of Septopal alone or combined with parenteral antibiotic is indicated.

A model of chronic osteomyelitis was used to evaluate the efficacy of treatment with debridement alone; debridement plus gentamicin-polymethylmethacrylate (PMMA) bead implantation; debridement plus systemic antibiotic therapy; and debridement plus systemic antibiotics and bead implantation. Debridement with the implantation of gentamicin-PMMA beads and debridement followed by systemic antibiotics were significantly more successful forms of treatment for chronic osteomyelitis than debridement alone or debridement with the implantation of PMMA beads not impregnated with antibiotics. Debridement followed by the implantation of PMMA-gentamicin beads and the use of systemic antibiotics produced the greatest success rate. Treatment with a combination of gentamicin-PMMA beads and systemic antibiotics resulted in a 100% success rate, which, although not statistically better than either treatment alone, suggests a trend.

This article reviews the complexity of the microbiological environment of odontogenic infections. With an understanding of the organisms involved, the appropriate antibiotic can be chosen. A review of current antibiotic choices and the rationale for their selection is also presented.

To determine the rate of physician and dentist compliance with the American Heart Association's (AHA) recommendations for prophylaxis against bacterial endocarditis--considered the standard of care--questionnaires were mailed to 1,131 dental and medical practitioners. They were asked to identify various cardiac conditions requiring prophylaxis and dental procedures that would cause a bacteremia, and to write prescriptions for prophylactic antibiotics for five different scenarios. Both groups had low compliance with AHA recommendations (32.9% collectively) when prescribing appropriate antibiotic regimens for bacterial endocarditis prophylaxis.

In a study of the duration of antibiotic prophylaxis in elective surgery, 466 procedures were surveyed over a four-year period. It is difficult to prove the efficacy of antibiotic prophylaxis when the rate of infection is so low, and, although not statistically significant, there is no difference in the infection rate whether the antibiotics are given intraoperatively only or for 48 hours, three days, or seven days. Per 100,000 patients, the cost savings of giving antibiotics intraoperatively rather than for 48 hours would have been $7,700,000; with the reduction from seven days to one-dose antibiotics, the savings would have been $29,700,000.

Using the total hip replacement patient, we measured the level of antibiotic in the wound at the time of surgery, the wound drainage for 36 to 48 hours after surgery and over a 10 day period in incubated surgical debris obtained at the time of total hip replacement. The antibiotics sodium oxacillin, lincomycin hydrochloride and sodium cephalothin were administered in standard doses at 6 hour intervals. In one group of patients the antibiotic was begun at the time of surgery, in a second group the antibiotic was begun 24 hours after the completion of surgery. Sodium oxacillin, lincomycin hydrochloride and sodium cephalothin produce antibiotic levels in the venous serum consistently above the level obtained in the simultaneous would drainage specimens. Sodium oxacillin and lincomycin hydrochloride used as described in this study are capable of bathing the area of the surgical wound with concentrations of antibiotics above the minimal inhibitory concentrations. This is evidenced by the antibiotic levels above minimal inhibitory concentrations found in the wound drainage. Sodium cephalothin levels in the wound drainage were below measurable levels in 3 of 4 patients. Sodium oxacillin and lincomycin hydrochloride antibiotic levels in the surgical wound debris and simultaneous venous clotted specimens diminished progressively in a similiar manner indicating no additional effects of the surgical wound debris on the antibiotic's biologic effectiveness. Sodium cephalothin dropped below measurable levels in three days. Measurable levels of antibiotics appeared in the wound aspirate well above the minimal inhibitory concentration in patients receiving their initial dose of sodium oxacillin 24 hours after surgery.

Admixing of several antibiotic powders which were insoluble in methyl methacrylate did not decrease the compressive and diametral tensile strengths of two acrylic bone cements when tested after setting for 1 day and after leaching 40 days in water at 37 degrees C. When antibiotics were added as water solutions, the included water resulted in a significant decrease in these bulk mechanical properties. Storage in water for 40 days caused surface irregularities only on specimens of the set antibiotic admixtures. Approximately 0.5% of the admixed dosage of these water-soluble antibiotics could be leached from the set cements. The observed surface channels, presumably left by the loss of antibiotic, suggest further study of surface-sensitive mechanical properties may be needed. The bulk mechanical strengths presented here are conclusive only for the particular combinations of antibiotics and cements investigated, and should not be generalized at this time to any or all antibiotic admixtures or other mechanical properties.

A fundamental prerequisite for the prevention of sepsis is adherence to well-known and accepted listerian principles of asepsis. This article reviews the roles of the high-risk patient, nutritional status, high-risk surgery, environmental factors, airborne contamination, preventive antibiotics, and antibiotic-acrylic composites in surgical sepsis.

In vitro and in vivo experiments were performed to study the antibacterial and mechanical properties of Simplex and Palacos acrylic bone cements utilized for the production of acrylic cement-antibiotic composites. Acrylic cement without antibiotic had no bacteriostatic effect on Staphylococcus aureus, Escherichia coli, and Pseudomonas. Oxacillin, cefazolin, and gentamicin are stable in acrylic cement and are released in a microbiologically active form. The three antibiotics diffused from the Palacos in larger amounts daily and for a significantly longer time than from the Simplex. Mechanical tests demonstrated that admixture of antibiotics and acrylic cement had no influence on the compressive and diametral tension strengths of the cement. Bacteriostatic concentrations of oxacillin in wound hematomas were measured for fourteen days after implantation of an oxacillin-Simplex composite in dogs. High bactericidal concentrations of the antibiotic were measured in the surrounding bone for twenty-one days after implantation.