Abstract

Periprosthetic joint infections continues to be a common complication in total joint arthroplasty, resulting in significant morbidity, mortality and additional costs. Antibiotic loaded bone cement has profoundly reduced the incidence of infection and revision. Trabecular metal implants with an internal cemented interface may be customizable drug delivery devices with an ingrowth interface. Thirty-six acetabular implants were assembled in vitro, half with a trabecular metal shell and half without. The antibiotic loaded bone cement was prepared via three different mixing techniques and at two mixing times. Mixing time had a significant effect on the total amount of gentamicin eluted. The long mix protocol eluted up to 126% (p=0.001) more gentamicin than the short mix at four hours and 192% (p<0.001) more at seven days. The use of a trabecular metal shell had no significant effect at four hours (p>0.05) but significantly reduced total elution under certain mixing protocols at seven days. Mixing technique had no significant effect on elution at four hours. At seven days, the mechanical mixing system under vacuum eluted over 50% (p=0.031) more antibiotic than without a vacuum and nearly 60% (p=0.040) more antibiotic than hand mixing. The use of trabecular metal implants does not significantly inhibit the initial bulk elution of gentamicin. A possible optimization strategy to improve elution kinetics would be to use a long mixing time with a mechanical mixing system under vacuum. This article is protected by copyright. All rights reserved.

View details for PubMedID 30839118