Treatment Outcomes in Septic Arthritis of the Foot and Ankle in People Who Inject Drugs.

Background: Although injection drug use (IDU) is a known risk factor for septic arthritis (SA) of the foot and ankle (F&A), disease and hospitalization outcomes are poorly characterized. We evaluated national trends, demographic characteristics, and hospitalization outcomes of SA of the F&A in people who inject drugs vs those who do not.

Methods: Using the Nationwide Inpatient Sample, we identified all patients aged 15-64 with a principal discharge diagnosis of SA of the F&A from 2000 to 2013 and evaluated if they were related or unrelated to IDU. We assessed differences in demographic characteristics and in-hospital outcomes in these groups.

Results: From 2000 to 2013, there were an estimated 14,198 hospitalizations for SA of the F&A in the United States, and 11% were associated with IDU (SA-IDU). Compared to SA unrelated to IDU, people with SA-IDU were significantly more likely to be younger, black, and have Medicaid or no insurance. People with SA-IDU were significantly more likely to leave against medical advice (9.7% vs 1.4%, P < .001), have a longer length of stay (9.2 vs 6.8 days, P < .001), and incur increased hospital charges ($58 628 vs $38 876, P = .005). People with SA-IDU were significantly less likely to receive an arthroscopy (1.5% vs 6.5%, P < .001) or arthrotomy (2.2% vs 11.0%, P < .001) of the foot.

Conclusions: People with SA-IDU of the F&A had suboptimal hospitalization outcomes with greater costs. Recognizing risk factors and proactively addressing potential complications of substance use disorder in the hospital should be prioritized by the orthopedic community. Methods: Level III, retrospective cohort study.