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 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.