Paper of the Week: Four versus six weeks of antibiotic therapy for osteoarticular infections after implant removal: a randomized trial.

Four versus six weeks of antibiotic therapy for osteoarticular infections after implant removal: a randomized trial. Benkabouche M, Racloz G, Spenchbach H, Lipsky BA, Gaspoz JM, Uçkay I. J Antimicrob Chemother 2019 May 18. Doi: 10.1093/jac/dkz202.

Summary and editorial by Dr. Marjan Wouthuyzen-Bakker

For several decades, osteoarticular infections after implant removal have been treated with antibiotics for a duration of six weeks. In this single-centre, unblinded, randomized trial, 123 patients were randomized to 4 or 6 weeks of systemic antibiotic treatment after infected hardware was removed (i.e. prosthetic joints, orthopaedic plates or nail implants). Most patients received intravenous antibiotics for 4 days before switching to oral. Intraoperative cultures were taken after a minimum antibiotic holiday of 2 weeks before re-implantation of hardware. Microbiological recurrence during reimplantation was observed in 2 of 62 patients in the 4-week arm (3.2%) versus 1 of 61 patients in the 6-week arm (1.6%) (P=0.57). Recurrence of clinical infection occurred in 4 out of 62 patients in the 4-week arm (6.5%) and in 3 out of 61 patients in the 6-week arm (4.9%) (P=0.74) during a minimum follow-up of 6 months (median follow-up of 2.2 years).

Based on these results, the authors demonstrate non-inferiority of a 4-week antibiotic treatment course compared to 6-weeks for osteoarticular infections after implant removal. It should be noted that a large proportion of included infections were acute and thus, its non-inferiority can probably not be extrapolated one on one to chronic infections with the presence of mature biofilm.

The study conducted by Benkabouche et al. again demonstrates that the habit of prescribing long courses of antibiotics can be questioned. Nowadays, several studies suggest that antibiotic duration can be shortened for indications that traditionally have been treated for longer periods, in particular prosthetic joint infections, provided that proper surgical debridement has been performed [1]. In addition, in agreement with the OVIVA trial [2], early switch to oral antibiotics can be safely performed if antibiotics are chosen with adequate oral bioavailability.

References

1. Lora-Tamayo J, Euba G, Cobo J et al. Short- versus long-duration levofloxacin plus rifampicin for acute staphylococcal prosthetic joint infection managed with implant retention: a randomised clinical trial. Int J Antimicrob Agents. 2016 Sep;48(3):310-6.
2. Li HK, Rombach I, Zambellas R et al. Oral versus Intravenous Antibiotics for Bone and Joint Infection. N Engl J Med. 2019 Jan 31;380(5):425-436.