Orthopaedic Consultant at North Shore Hospital with an interest Hand Surgery and Arthroplasty
Arthroplasty Fellowship University Hospital, London Health Science Centre, University of Western Ontario, Canada
BACKGROUND:
In response to increasing antibiotic resistance, vancomycin has been proposed as an alternative prophylactic agent in TKA. However, vancomycin requires a prolonged administration time, risks promoting further antibiotic resistance, and can cause systemic toxicity. Intraosseous regional administration (IORA) is known to achieve markedly higher antibiotic concentrations than systemic administration and may allow the use of a lower vancomycin dose.
QUESTIONS/PURPOSES:
We assessed whether low-dose IORA vancomycin can achieve tissue concentrations equal or superior to those of systemic administration in TKA and compared complications between patients treated with IORA and intravenous vancomycin.METHODS:
We randomized 30 patients undergoing primary TKA to receive 250 or 500 mg vancomycin via IORA or 1 g via systemic administration. IORA was performed as a bolus injection into a tibial intraosseous cannula below an inflated thigh tourniquet immediately before skin incision. Subcutaneous fat and bone samples were taken during the procedure and antibiotic concentrations measured.
RESULTS:
The overall mean tissue concentration of vancomycin in subcutaneous fat was 14 μg/g in the 250-mg IORA group, 44 μg/g in the 500-mg IORA group, and 3.2 μg/g in the systemic group. Mean concentrations in bone were 16 μg/g in the 250-mg IORA group, 38 μg/g in the 500-mg IORA group, and 4.0 μg/g in the systemic group. One patient in the systemic group developed red man syndrome during infusion.
CONCLUSIONS:
Low-dose IORA vancomycin results in tissue concentrations equal or superior to those of systemic administration. IORA optimizes timing of vancomycin administration, and the lower dose may reduce the risk of systemic side effects while providing equal or enhanced prophylaxis in TKA.Longer operative times may be required in complex total knee arthroplasty (TKA), however little is known about outcomes in procedures performed rapidly. We analysed 58,009 primary TKAs from the New Zealand National Joint Registry. The mean surgical duration was 89minutes, and 50% of procedures lasted between 60 and 89minutes. There was no difference in adjusted revision rates for groups lasting between 40 and 120minutes, however procedures lasting >120minutes had significantly higher revision rates. There was a higher revision rate in TKAs lasting <40minutes (0.71 vs 0.48 revisions per 100 component years) but this was not statistically significant (P=0.1). For primary TKAs lasting less than 120minutes, further shortening operative time did not improve outcome, and very rapid procedures (<40minutes) may lead to an increased risk of revision.
