Antibiotic susceptibility in gram-positive chronic joint arthroplasty infections: increased aminoglycoside resistance rate in patients with prior aminoglycoside-impregnated cement spacer use

J Arthroplasty. 2014 Aug;29(8):1617-21. doi: 10.1016/j.arth.2014.03.029. Epub 2014 Mar 29.


Two-stage revision using aminoglycoside-cement spacers (A-CSs) is widely used to manage chronic periprosthetic joint infection (PJI). However, aminoglycoside-resistance in gram-positive cocci (GPC) seems to be increasing. Moreover, the contribution of these A-CSs to select resistant mutants is a matter of concern. We study the antibiotic susceptibility profile of GPC after 113 chronic hip and knee PJIs. Aminoglycoside susceptibility-profiles were compared between cases where A-CSs had previously been used (n: 52), and cases of primary infection (n: 61). 32% of isolates were resistant to gentamicin and 40.6% to tobramycin. Gentamicin resistance after previous A-CS use was significantly higher (49.2% [30/61] vs. 19.3% [16/83]; P: 0.0001) as well as with tobramycin (52.7% [29/55] vs. 30.9% [21/66]; P: 0.014). A high rate of gentamicin-tobramycin resistance exists among the most common bacteria involved in chronic-PJI. The risk of selection for aminoglycoside-resistant mutants in cases of infection relapse is a concern following A-CS use.

Keywords: antibiotic loaded spacers; antibiotic resistance; gentamicin; periprosthetic joint infection; tobramycin.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Anti-Bacterial Agents / administration & dosage*
  • Arthroplasty, Replacement, Hip / adverse effects*
  • Arthroplasty, Replacement, Knee / adverse effects*
  • Bone Cements / therapeutic use
  • Chronic Disease
  • Drug Resistance, Bacterial
  • Female
  • Gentamicins / administration & dosage
  • Gram-Positive Bacterial Infections / drug therapy*
  • Humans
  • Male
  • Middle Aged
  • Prosthesis-Related Infections / drug therapy*
  • Prosthesis-Related Infections / surgery*
  • Retrospective Studies
  • Secondary Prevention
  • Tobramycin / administration & dosage


  • Anti-Bacterial Agents
  • Bone Cements
  • Gentamicins
  • Tobramycin