Antibiotic-associated complications following lower limb arthroplasty: a comparison of two prophylactic regimes

As part of a wider drive to reduce Clostridium difficile rates (CDAD), our trust switched from cefuroxime to gentamicin and flucloxacillin prophylaxis for joint replacement surgery. Anecdotal evidence suggested that we were seeing an increased incidence of acute kidney injury (AKI) following elective total hip replacement (THR) and total knee replacement (TKR) since this change. The aim of this study was to compare rates of AKI and post-operative infection between the two antibiotic regimes.

We carried out a single-centre retrospective cohort study comparing 200 patients (100 THR and 100 TKR) who received cefuroxime with another age and procedure-matched group who received gentamicin and flucloxacillin (gentamicin 3 mg/kg and 5 g flucloxacillin in total). We compared rates of AKI, haemofiltration, CDAD, surgical site infection (SSI) and return to theatre for infection (RTT).

Gentamicin was associated with a significant increase in AKI (1 vs. 8%, p < 0.01). More patients needed haemofiltration (0 vs. 1.5%) although this was not significant. Interestingly, when the groups were subdivided into THR and TKR, significantly more TKR patients receiving gentamicin developed AKI (0 vs. 11, p < 0.01). This difference was not significant following THR (2 vs. 5, p = 0.44). This may be related to tourniquet use in TKR. SSI and RTT were comparable. No patient developed CDAD.

Gentamicin with flucloxacillin is comparable with cefuroxime in rates of SSI and RTT but is associated with a significant increase in AKI. AKI is associated with additional morbidity and mortality. This association should be considered when choosing a suitable prophylactic regime.