Risk of septic arthritis following corticosteroid and platelet-rich plasma injections: A multicenter retrospective review.

BACKGROUND

Platelet-rich plasma injections (PRPI) are a relatively new and evolving treatment option for a variety of musculoskeletal injuries. It has been theorized that there is an increased risk of septic arthritis (SA) with PRPI, though there have been no dedicated studies to assess the incidence of SA and only three cases have been previously reported to the authors' knowledge. By comparison, corticosteroid injections (CSI) have been a widely used treatment for decades, with a well-established risk profile and a variably reported incidence of SA between 1 in 555 to 77,000 injections.

OBJECTIVE

To identify the incidence of SA after peripheral joint/bursa PRPI, specifically in comparison to CSI.

DESIGN

Case-Control Series.

SETTING

Two large academic medical centers.

MAIN OUTCOME MEASURE(S): Incidence of SA, location of infection.

PATIENTS: All patients who underwent CSI or PRPI over the study timeframe.

METHODS

A search of electronic medical records was conducted to identify patients who underwent CSI and PRPI, with a subsequent encounter for a joint infection within 3-60 days of injection. Records were then reviewed by a physician to verify correlation.

RESULTS

A total of 1,067,498 total injections were identified in 366,541 patients: 1,053,953 CSIs in 358,079 patients and 13,545 PRPIs in 8462 patients. There were 69 confirmed cases of SA after CSI and one case of SA after PRPI. The incidence of SA after CSI and PRPI was 1 per 15,275 (95% CI 12,077-19,342) injections and 1 per 13,545 (95% CI 2392-76,923) injections, respectively.

CONCLUSIONS

To the authors' knowledge, this is the first study to report the incidence of SA following peripheral joint/bursa PRPI. One case of SA after PRPI was identified. There is a low incidence of SA after both CSI and PRPI, consistent with previously published data for CSI.