One Week of Antibiotics Matched Four Weeks After Bone Infection Surgery
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- In the SOLARIO trial, infection came back or treatment failed within 12 months in 11.1% of patients given 7 days or less of antibiotics and 14.1% of those given 4 weeks or more, the investigators reported in NEJM.
- Symptoms possibly caused by treatment affected 17.2% of the short-course group and 45.2% of the long-course group by week 6, according to the NEJM report.
- Every patient had surgery to remove infected tissue and had a local antibiotic carrier placed in the wound, which the investigators said releases drug for at least 4 weeks.
- The trial left out patients who kept an infected implant in place or had germs resistant to the local antibiotic, according to the published protocol.
Table of Contents
- What a Bone Infection Is and How Surgeons Treat It
- What the SOLARIO Trial Tested About Antibiotics for Bone Infection
- How the Short Course Compared on Cure
- Side Effects
- Who the Results Apply To
- Research Gap
- Closing Thoughts
What a Bone Infection Is and How Surgeons Treat It
A bone infection, or osteomyelitis, happens when bacteria settle in bone and the tissue around it. It often follows a broken bone, an artificial joint or a diabetic foot ulcer.
Treatment usually means surgery to cut out dead and infected bone, a step called debridement. For decades, the standard plan for antibiotics for bone infection was at least 4 weeks after surgery, often through an IV line, and the trial protocol describes the usual course as at least 4 to 6 weeks [2].
Contagion Live reported that the investigators framed their trial as a test of that standard [5]. They wrote that it “challenges the standard of care for orthopedic infection.”
That long course long courses add selection pressure for resistant bacteria costs. The trial’s protocol notes that about 1 in 6 patients treated with antibiotics for chronic osteomyelitis has an adverse drug reaction, and long courses add selection pressure for resistant bacteria [2].
An earlier Oxfhad already changed part of the picture in 2019.
It found that antibiotic pills worked as well as IV antibiotics for the first of bone and joint infections [3]. That study did not test a shorter course. The question of length stayed open.
What the SOLARIO Trial Tested About Antibiotics for Bone Infection
The Short or Long Antibiotic Regimes in Orthopaedics trial, known as SOLARIO, asked whether the length of that course could drop to a week. The results appeared in the New England Journal of Medicine on Sept. 16, 2026 [1].
Martin McNally, MD, of the Bone Infection Unit at the Nuffield Orthopaedic Centre, Oxford University Hospitals, led the study. It enrolled 500 adults at centers in the United Kingdom and mainland Europe, and 475 were included in the main analysis [1, 4].
Every patient had definitive surgery for a confirmed bone or joint infection. During that surgery, the team placed a local antibiotic carrier, a material packed into the cleaned-out bone that slowly releases antibiotic right where the infection was.
The carriers were either absorbable materials or polymethylmethacrylate, a bone cement. Both types released antibiotic for at least 4 weeks, according to the report [1].
After surgery, patients were randomly assigned to one of two groups.
One group took antibiotics by mouth or vein for 7 days or less. The other took them for 4 weeks or more. Infectious disease specialists chose the drugs.
The trial included 4 kinds of infection: osteomyelitis, infected artificial joints, infections after a fracture repair and diabetic foot infections [2]. The main result was treatment failure within 12 months, judged by a committee that did not know which group each patient was in.
How the Short Course Compared on Cure
Treatment failed in 26 of 234 patients in the short-course group, or 11.1%. It failed in 34 of 241 patients in the long-course group, or 14.1% [1].
The difference was 3.0 percentage points in favor of the short course, with a 95% confidence interval of 9.0 points lower to 3.0 points higher. That range sat inside the trial’s preset limit, so the investigators concluded the short course was noninferior, meaning not meaningfully worse.
The limit was 10 percentage points. The protocol explains where that number came from: most patient advisers surveyed said they would accept a cure chance of 8 in 10 instead of 9 in 10 to avoid 4 weeks of antibiotic side effects [2].
The trial was designed to rule out a large loss of benefit. Its lower failure rate in the short-course group does not show that the short course works better.
Side Effects
The gap in side effects was large. By week 6 after surgery, 17.2% of short-course patients had symptoms that may have come from treatment. In the long-course group, 45.2% did [1].
For a patient, a shorter course means fewer weeks of antibiotics after surgery. The trial report as covered did not put a dollar figure on any savings.
Who the Results Apply To
SOLARIO tested one specific approach, and the result is tied to it. Every patient had the infected tissue removed and had a local antibiotic carrier left behind. A patient who has surgery without a carrier falls outside what this trial studied.
The protocol also excluded several groups [2]:
- Patients whose surgeons planned a second look operation or whose first surgery was not meant to be definitive.
- Patients who kept an infected implant in place, a procedure known as DAIR (debridement, antibiotics and implant retention).
- Patients whose bacteria resisted the antibiotic in the carrier.
- Patients with another infection that needed more than 7 days of antibiotics.
People facing surgery for a bone infection may want to ask their surgeon whether a local antibiotic carrier is part of the plan, whether their case matches the trial’s criteria and how long antibiotics would run after surgery. Those decisions depend on the germ, the implant and the patient’s health, and they belong with the treating team.
Research Gap
The trial was open-label, so patients and their doctors knew which group they were in. That can affect how people report symptoms, which matters most for the side-effect result. A blinded committee judged the main outcome, which limits that risk for the cure result.
Follow-up ran for 12 months. Bone infections can return years later, and this report does not show what happens after the first year.
Most patients were treated at specialist bone infection centers in the United Kingdom and Europe. Results at hospitals that treat fewer of these cases, or that use different carriers, may differ. The full NEJM paper was not available to read for this article, so breakdowns by infection type come from the protocol rather than the results.
Closing Thoughts
For adults who have infected bone removed and a local antibiotic carrier placed, SOLARIO found that a week of antibiotics after surgery prevented treatment failure about as well as a month, with far fewer side effects.
The result does not cover implants left in place, surgery without a carrier or recurrences past the first year. Those questions remain for future trials and for each patient’s own care team.
References
[1]. McNally, M., Dudareva, M., Kümin, M., Vach, W., Scarborough, C. L., Cichero, M. J., Sousa, R., Ferguson, J., Stubbs, D. A., Atkins, B. L., Ramsden, A. J., Young, B. C., Carvalho, A. D., Kendal, A. R., Alvand, A., Palmer, A. J. R., Loizou, C. L., Kendrick, B., Taylor, A. H., . . . Scarborough, M. (2026). Short or long antibiotic regimens in orthopedics. New England Journal of Medicine. https://doi.org/10.1056/NEJMoa2506756
[2]. Dudareva, M., Kümin, M., Vach, W., Kaier, K., Ferguson, J., McNally, M., & Scarborough, M. (2019). Short or Long Antibiotic Regimes in Orthopaedics (SOLARIO): A randomised controlled open-label non-inferiority trial of duration of systemic antibiotics in adults with orthopaedic infection treated operatively with local antibiotic therapy. Trials, 20, Article 693. https://doi.org/10.1186/s13063-019-3832-3
[3]. Li, H.-K., Rombach, I., Zambellas, R., Walker, A. S., McNally, M. A., Atkins, B. L., Lipsky, B. A., Hughes, H. C., Bose, D., Kümin, M., Scarborough, C., Matthews, P. C., Brent, A. J., Lomas, J., Gundle, R., Rogers, M., Taylor, A., Angus, B., Byren, I., . . . Scarborough, M. (2019). Oral versus intravenous antibiotics for bone and joint infection. New England Journal of Medicine, 380(5), 425–436. https://doi.org/10.1056/NEJMoa1710926
[4]. Oxford University Hospitals NHS Trust. (2019). Short or Long Antibiotic Regimes in Orthopaedics (SOLARIO) (ClinicalTrials.gov Identifier NCT03806166). https://clinicaltrials.gov/study/NCT03806166
[5]. Bender, K. (2026, September 23). Implanted antibiotic reduced systemic regimen for orthopedic infection. Contagion Live. https://www.contagionlive.com/view/implanted-antibiotic-reduced-systemic-regimen-for-orthopedic-infection
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