A COMPARISON OF GENTAMICIN-IMPREGNATED POLYMETHYLMETHACRYLATE BEAD IMPLANTATION TO CONVENTIONAL PARENTERAL ANTIBIOTIC-THERAPY IN INFECTED TOTAL HIP AND KNEE ARTHROPLASTY

A multicenter study of infected total knee and total hip arthroplastie s was conducted from 1985 until 1990. Twenty-eight patients (22 total hip arthroplasties and six total knee arthroplasties) who had peripros thetic infections were treated according to a prospective, randomized protocol. After initial debridement for their infections, patients wer e randomized into one of the two following groups: Group I, debridemen t and the implantation of gentamicin-polymethylmethacrylate (PMMA) bea ds; and Group 2, debridement and conventional parenteral systemic anti biotic therapy. After initial treatment, the patients were then schedu led for a delayed reconstruction total joint arthroplasty. Of the 28 p atients, 25 subsequently had delayed total arthroplasty, and if acryli c bone cement was used for fixation at the time of reimplantation, ant ibiotics were not added to the cement. The average follow-up period wa s three years (range, six months to 5.6 years). Infection recurred in two patients treated by debridement and the implantation of gentamicin -PMMA beads (1 5%) and in four patients treated with debridement and c onventional systemic antibiotic therapy (30%). All recurrences occurre d 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 infect ion, and (4) inadequate debridement. The recurrence of infection was n ot statistically significantly more common in either treatment group. The outcome of treatment in patients with infected total joint arthrop lasties using debridement, gentamicin-PMMA bead implantation, and a tw o-stage delayed reconstruction was similar to that of patients treated with debridement combined with conventional parenteral systemic arthr oplasty and two-stage reconstruction.