Can 7 Days of Antibiotics Cure Bone and Joint Infection?

Orthopedic infection management traditionally requires extensive surgical debridement and prolonged systemic antimicrobial therapy. Clinicians routinely prescribe several weeks of systemic agents to prevent treatment failure. However, prolonged regimens expose patients to toxicities, catheter complications, and antimicrobial resistance. Consequently, optimizing orthopedic infection antibiotics represents a critical priority in modern surgical practice. The landmark SOLARIO trial directly evaluated whether local antibiotic delivery can shorten systemic antibiotic duration without compromising clinical cure.

Optimizing Orthopedic Infection Antibiotics With Local Delivery

Surgeons frequently insert antibiotic-loaded biomaterials into infected bone cavities or debrided joints. These carriers deliver exceptionally high local concentrations of antimicrobial agents directly at the infection site. Furthermore, local elution achieves bactericidal levels far exceeding the minimum inhibitory concentrations for biofilm-forming pathogens. Because the carrier handles the local bioburden, researchers questioned whether patients still need weeks of systemic medications. Therefore, investigators designed the multicenter, open-label, noninferiority SOLARIO trial.

The trial enrolled 500 adult patients undergoing surgery for orthopedic infections, including osteomyelitis and prosthetic joint infections. In addition, surgeons implanted a local-antibiotic carrier during the procedure in all participants. Following surgery, investigators randomly assigned patients to receive either a long regimen or a short course. Specifically, the long regimen lasted at least four weeks, whereas the short course lasted seven days or less.

Key Efficacy Outcomes and Noninferiority Results

The primary outcome was definite treatment failure within 12 months after surgical intervention. An independent clinical end-point committee assessed outcomes while remaining fully unaware of treatment allocations. Moreover, the trial protocol specified a noninferiority margin of 10 percentage points.

Among 475 patients in the primary analysis, definite treatment failure occurred in 14.1% of the long-duration group. In contrast, treatment failure occurred in only 11.1% of the short-duration cohort. The risk difference was -3.0 percentage points with a 95% confidence interval of -9.0 to 3.0 percentage points. Thus, the short regimen comfortably achieved the prespecified noninferiority criterion. Sensitivity analyses in the overall cohort and per-protocol groups demonstrated entirely consistent findings. Consequently, seven days of systemic coverage provided identical therapeutic efficacy to four weeks or more.

Substantial Reductions in Treatment-Related Adverse Events

Beyond proving noninferior efficacy, the shorter systemic duration showed striking advantages in patient safety. By week six after surgery, treatment-related adverse symptoms developed in 45.2% of patients receiving long antibiotic therapy. Conversely, only 17.2% of patients in the short-duration group experienced such symptoms. This difference represents a statistically significant risk reduction of 28.0 percentage points.

Prolonged antibiotic administration often triggers gastrointestinal distress, nephrotoxicity, and secondary opportunistic infections. Additionally, extended intravenous access increases the risk of vascular thrombosis and catheter-associated bacteremia. By limiting systemic antibiotics to one week, clinicians dramatically reduce medication burden and potential drug interactions. Therefore, this paradigm shift promotes patient comfort while maintaining rigorous infection eradication.

Implications for Clinical Practice and Antibiotic Stewardship

These results will reshape management protocols across orthopedic and reconstructive surgery units worldwide. In settings with high antimicrobial resistance rates, curbing unnecessary antibiotic exposure is paramount. For example, shorter regimens reduce selective pressure on hospital flora and preserve the efficacy of vital broad-spectrum antimicrobials. Furthermore, shorter courses lower healthcare expenditures by minimizing pharmacy costs, intravenous equipment needs, and prolonged hospitalizations.

Surgical teams must nevertheless ensure proper debridement and appropriate local carrier placement before shortening systemic therapy. When surgeons achieve source control and deliver adequate local antibiotics, seven days of systemic coverage is sufficient. Consequently, clinicians can safely discontinue systemic antibiotics early, confident in delivering both safety and clinical cure.

Frequently Asked Questions

Q1: What did the SOLARIO trial determine about systemic antibiotic duration in orthopedic infection?

The SOLARIO trial evaluated systemic antibiotic duration alongside local antibiotic carriers. It demonstrated that seven days or fewer of systemic therapy was noninferior to four weeks or more.

Q2: How much did adverse treatment symptoms decrease with the shorter antibiotic regimen?

Adverse symptoms occurred in only 17.2% of patients receiving the short regimen compared to 45.2% receiving the long regimen. This represents an absolute risk reduction of 28.0 percentage points.

Q3: Can clinicians apply this short antibiotic regimen without local antibiotic carriers?

No, the trial examined patients who received implanted local-antibiotic carriers during surgical debridement. Therefore, clinicians should not extrapolate these results to patients treated without local antibiotic delivery.

References

1. McNally M et al. Short or Long Antibiotic Regimens in Orthopedics. N Engl J Med. 2026 Sep 16. doi: 10.1056/NEJMoa2506756. PMID: 42748421.
2. Dudareva M, Kümin M, Vach W, et al. 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. 2019;20(1):693.
3. Li HK, Rombach I, Zambellas R, et al. Oral versus Intravenous Antibiotics for Bone and Joint Infection. N Engl J Med. 2019;380(5):425-436.