The Safety of Glycopeptide-Impregnated Calcium Sulphate Following Debridement, Antibiotics and Implant Retention (DAIR) for Infected Total Knee Replacement.

ABSTRACT

Background and objective The impact of prosthetic joint infection (PJI) stretches far beyond the physical nature of the disease. It can result in psychological and social consequences, with significant morbidity and mortality for patients. Calcium sulphate-based delivery agents are effective in the management of PJI, yet with associated risks of systemic adverse events. This study aims to evaluate the risk of systemic adverse events when using calcium-sulphate-based local antibiotic delivery agents in the management of PJIs. Methodology We identified 43 patients who underwent debridement, antibiotics and implant retention (DAIR) for infected total knee arthroplasty (TKA) between 2008 and 2014. Patients in the control groupunderwent conventional intravenous and then oral antibiotic administration, while those in the intervention groupunderwent additional local antibiotic therapy via a calcium sulphate alpha hemihydrate matrix. Case notes and laboratory results data were compiled to establish the safety and efficacy of local glycopeptide delivery. Results Serum vancomycin levels were within the safe therapeutic range for all patients in the intervention group with no difference in serum assays between treatment groups (intervention 7.7 mg/L; control 8.0 mg/L; P = 0.85). Renal function for the study cohort improved at every time point post-operatively when referenced against pre-operative renal function (P < 0.05). There was no difference in renal function between intervention and control groups on day 1, one week, six weeks or 12 weeks post-operatively (P = 0.78, 0.89, 0.20 and 0.50). Conclusions Local glycopeptide delivery via a calcium sulphate alpha hemihydrate matrix did not result in systemic adverse consequences specifically not raising the systemic level of glycopeptide, nor reducing renal function. Implications for future research Although demonstrates a safety profile and potential therapeutic benefit, the long-term efficacy of this approach needs to be established. Importantly, selection bias may contribute to masking clinically significant differences in post-operative outcomes.