Response to: Release of gentamicin and vancomycin from temporary human hip spacers in two-stage revision of infected arthroplasty. Authors' reply

Sir, A recent article by Bertazzoni Minelli et al. 1 proposes new treatment options for the increasing problem of implant infection caused by resistant strains and describes the release of gentamicin and vancomycin from poly-methyl-methacrylate (PMMA) spacers. However, their interpretation that ‘a high clinical response rate’ would support the clinical potential of these devices seems to overlook several factors. (i) The small number of positive pre-operative cultures (nine of the 20 patients treated), and the lack of specificity of blood-tests and radiographs 2 undermine the clinical evidence of infection that was stated by the authors. (ii) The effect of local treatment with the spacers is obscured by concomitant antibiotic treatment in all patients, because a combination of parenteral and oral therapy may result in a 84 –91% success rate. 3 (iii) The low combined antibiotic release (0.2 mg/g) does not meet the minimal release requirements