Two-stage revision treatment of prosthetic joint infection (PJI) frequently employs the use of a temporary bone cement spacer loaded with multiple antibiotic types. Tobramycin and vancomycin are commonly used antibiotics in cement spacers, however, there is no consensus on the relative concentrations and combinations that should be used. Therefore, the purpose of this study was to investigate the influence of dual antibiotic loading on the total antibiotic elution and compressive mechanical properties of acrylic bone cement. Varying concentrations of tobramycin (0-3 g) and vancomycin (0-3 g) were added either alone or in combination to acrylic cement (Palacos R), resulting in 12 experimental groups. Samples were submerged in 37°C saline for 28 d and sampled at specific time points. The collected eluent was analyzed to determine the cumulative antibiotic release. In addition, the cement's compressive mechanical properties and porosity were characterized. Interestingly, the cement with the highest concentration of antibiotics did not possess the best elution properties. Cement samples containing both 3 g of tobramycin and 2 g vancomycin demonstrated the highest cumulative antibiotic release after 28 d, which was coupled with a significant decrease in the mechanical properties and an increased porosity. The collected data also suggests that tobramycin elutes more effectively than vancomycin from cement. In conclusion, this study demonstrates that high antibiotic loading in cement does not necessarily lead to enhanced antibiotic elution. Clinically this information may be used to optimize cement spacer antibiotic loading so that both duration and amount of antibiotics eluted are optimized. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1078-1085, 2018.

A 12-year-old male with a family history of inflammatory bowel disease presented with sleep-disordered breathing and was found to have chronic, granulomatous swelling of the supraglottic larynx. His airway was managed with tracheostomy, regular interval laryngeal steroid injections, supraglottoplasty, and “pepper pot” CO2 laser resurfacing leading to eventual decannulation. Due to the non-necrotic nature of the granulomatous inflammation, as well as the patient’s family history of inflammatory bowel disease, the leading diagnosis was Crohn disease, but isolated laryngeal sarcoidosis could not be ruled out. There are only 13 reported cases of laryngeal manifestations of Crohn disease in the literature, with only 2 cases occurring in pediatric patients. This case report adds to this body of literature and discusses strategies for managing granulomatous supraglottic edema when definitive diagnosis is not fully clear.