Edelstein AI, et al. - This study assessed the systemic absorption of antibiotics following placement of antibiotic-loaded cement spacers (ACS) to treat periprosthetic joint infections (PJI). For this purpose, researchers measured serum concentrations of antibiotics post-placement of ACS and found that systemic absorption of antibiotics from high-dose ACS persisted for at least 8 weeks. A close surveillance is required in these patients to keep an eye on complications that follow such treatments.

Methods

• This prospective study included patients with an infected primary total hip (THA) or knee arthroplasty (TKA) treated with standardized antibiotic-loaded cement spacers with vancomycin, gentamicin, and tobramycin.
• Researchers collected serum antibiotic levels weekly for 8 weeks.

Results

• This study included overall 21 patients (10 THA, 11 TKA).
• Findings demonstrated that mean serum gentamicin levels ranged between 0.275 ± 0.046 and 0.364 ± 0.163 mg/L; mean serum tobramycin levels ranged from 0.313 ± 0.207 and 0.527± 0.424 mg/L; and mean serum vancomycin levels ranged from 5.46 ± 6.6 to 15.34 ± 9.6 mg/L.
• Researchers observed that serum antibiotic levels were detectable throughout the 8-week duration of ACS treatment.
• It was shown in regression analysis that serum vancomycin levels correlated with diabetes (coefficient 6.73, 95% CI 0.92-12.54, p<0.05), BUN (0.83, 95% CI 0.45 – 1.22, p<0.001), number of cement doses (3.71, 95% CI 0.76-6.66, p<0.05), and use of systemic vancomycin (6.24, 95% CI 2.72-9.75, p<0.001).
• In addition, data revealed correlation of patient age (coefficient -0.01, 95% CI -0.02-0, p<0.01) and male sex (0.20, 95% CI 0-0.41, p<0.05) with serum aminoglycoside level.