Risk factors for readmission and mortality after irrigation & debridement for septic arthritis in persons who inject drugs

Abstract

Background and objective

Persons who inject drugs (PWID) are associated with increased risk of repeat irrigation & debridement (I&D) in the setting of native joint septic arthritis. Despite these associations, there is a lack of data regarding postoperative outcomes for PWID with septic arthritis. The primary aim of this study was to determine if PWID were associated with increased rates of readmission and mortality after I&D for septic arthritis.

Materials and methods

Patients from two level one trauma centers with native joint septic arthritis from 2015 to 2019 were retrospectively identified. Patients were included if they had a clinical presentation consistent with septic arthritis. Independent sample T-tests and Fisher's Exact testing were used to compare outcomes by PWID and repeat I&D status. Primary outcomes included 30 and 90-day readmission, 30 and 90-day readmission related to septic arthritis, and 30 and 90-day mortality. Binary logistic regression testing was used to control for confounders such as human immunodeficiency virus (HIV), tobacco use disorder, diabetes, and immunocompromised status.

Results

192 patients with septic arthritis were identified (female, n = 70; male, n = 122). 231 joints were included in the analysis. There were 67 cases associated with PWID (29 %). Notably, PWID were associated with increased rates of tobacco use disorder (92 % vs. 24 %, p < 0.001) and increased immunocompromised status (81 % vs. 24 %, p < 0.001). PWID were associated with increased rates of 30-day and 90-day readmission (35 % vs. 12 %, p = 0.008; 61 % vs. 21 %, p = 0.002), and increased 30-day and 90-day mortality rate (22 % vs. 0.03 %, p < 0.001; 35 % vs 0.09 %, p = 0.001). However, these associations did not remain significant after controlling for confounders. Repeat I&D was significantly associated with increased 90-day readmission rates (OR 6.32, p < 0.001), which remained significant when controlling for confounders.

Conclusions

This multicenter study demonstrated a strong association between repeat I&D and 90-day readmission rate in the setting of native joint septic arthritis. Reassuringly, repeat I&D was not associated with increased rates of postoperative mortality. PWID were associated with increased 30 and 90-day readmission and mortality rates, but these were no longer significant after controlling for confounders.