This is a plain English summary of an original research article
For adults with bone or joint infection, many of whom had metal implants, beginning six weeks of oral antibiotics within seven days of intravenous treatment, was no worse than a regimen delivered wholly intravenously (IV). After one year, around 14% of both groups still had an infection, showing the difficulty of treatment, irrespective of the route of administration.
Although current practice suggests antibiotics should be given IV for bone and joint infections, for at least six weeks, this large NIHR-funded UK trial challenges this assumption. Participants were randomised to oral antibiotics seven days after initial surgical or IV antibiotic treatment.
Using oral antibiotics has the potential to reduce complications and give patients greater freedom while undergoing treatment, and costs less. This study strengthens evidence from an existing Cochrane review of smaller diverse trials, and may potentially lead to a shift in practice.
Why was this study needed?
Bone infection in adults can occur as a serious complication of joint replacement surgery, or when infection travels through the bloodstream from another source, or a side effect of diabetes.
IV antibiotics for four to six weeks or longer are the usual treatment. The prolonged intravenous access carries its own risk and can pose a considerable inconvenience to patients due to long hospital stays or therapy at home. Costs are approximately 10 times that of oral therapy.
IV antibiotics continue to be used, in part because of a long-standing assumption and prior research that this mode of delivery is more effective. However, a recent Cochrane review of small trials did not demonstrate that IV antibiotics were any better than those given orally, but the evidence was uncertain. This large trial aimed to see if there were any long term differences.
What did this study do?
The OVIVA randomised controlled trial had 1,015 participants from 26 UK centres. Patients were enrolled within seven days of either surgery or IV antibiotics to treat infection in the bone or joint. Causes ranged from a joint replacement infection to diabetes complications. Most had Staphylococcus aureus infections, and over 90% had initial surgical treatment.
Both the IV and the oral group received antibiotics for at least six weeks. In accordance with usual practice, the IV group could also be given oral antibiotics, such as rifampicin. Similarly, the oral group could have up to five consecutive days of IV antibiotics for unrelated infections; over 80% of the oral group started with IV antibiotics. The primary outcome was treatment failure within one year.
What did it find?
- A similar proportion of people in each group still had an infection at one year: 67/509 (13.2%) of the oral group and 74/506 (14.6%) in the IV group (risk difference ‑1.5, 95% confidence interval [CI] ‑5.7 to 2.8).
- Adverse events, ranging from trips and falls to allergic reactions, happened to just over a quarter of participants in both groups: 138/527 (26.2%) in the oral group and 146/527 (27.7%) in the IV group.
- Patients in the oral group had a median length of stay three days shorter than patients in the IV group (11 days [interquartile range, 8 to 20] vs 14 days [interquartile range, 11 to 21]).
What does current guidance say on this issue?
There is currently no national guidance on the management of bone and joint infection, but several local NHS guidance documents exist. For example, NHS Bolton recommends that the infection is confirmed either through bone, blood or deep tissue samples before initiation of antibiotic therapy.
Although the nature of the infection impacts upon the exact antibiotic regime, IV antibiotics are always the first line treatment. However, the type of antibiotic and duration of treatment does differ according to the exact indication.
For example, acute bone infection will be treated with IV antibiotics for four to six weeks, although after two weeks a switch to oral antibiotics may be considered.
What are the implications?
This research provides good evidence that bone and joint infections can be treated with predominantly oral regimens. This could have several benefits, not least the greater freedom afforded to patients and reduced costs.
The importance of taking the medication and potential treatment side effects need to be explained so that patients can seek medical support to modify the treatment when necessary.
Also, staff perceptions surrounding the effectiveness of oral antibiotics for this indication also need to be addressed to enable a shift in practice.
Citation and Funding
Li HK, Rombach I, Zambellas R, Walker AS et al.; OVIVA Trial Collaborators. Oral Versus Intravenous Antibiotics for bone and joint infection. N Engl J Med. 2019; 380(5):425-36.
This project was funded by the NIHR Health Technology Assessment Programme (project number 11/36/29), the NIHR Biomedical Research Centre at Imperial College and the NIHR Biomedical Research Centre at Oxford.
Boucher HW. Partial oral therapy for osteomyelitis and endocarditis — is it time? N Engl J Med 2019;380:487-9.
Conterno LO, Turchi MD. Antibiotics for treating chronic osteomyelitis in adults. Cochrane Database Syst Rev. 2013;9:CD004439.
NHS website. Osteomyelitis. London: Department of Health and Social Care; updated 2017.
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