Cumulative Intraarticular Injections Are Not a Risk Factor for Periprosthetic Joint Infection Following total Knee Arthroplasty.

BACKGROUND

While injections within 90 days prior to total knee arthroplasty (TKA) are associated with an increased risk of periprosthetic joint infection (PJI), there is a paucity of literature regarding the impact of cumulative injections on PJI risk. This study was conducted to assess the association between cumulative corticosteroid and hyaluronic acid (HA) injections and PJI risk following TKA.

METHODS

This retrospective study using an injection database included patients undergoing TKA with a minimum 1-year follow-up from 2015 to 2020. Patients with injections within 90 days prior to surgery were excluded. The sum of corticosteroid and HA injections within five years prior to TKA was recorded. The primary outcome was PJI within 90 days following TKA. Area under the curve (AUC) values were calculated for a cumulative number of injections.

RESULTS

648 knees with no injections and 672 knees with injections prior to TKA were included, among whom 243 received corticosteroids, 151 received HA, and 278 received both. No significant differences in early PJI rates existed between patients who received injections (0.60%) or not (0.93%) (P = .541). No significant differences existed in early PJI rates between patients injected with corticosteroids (0.82%), HA (0.66%), or both (0.36%) (P = .832). No cutoff number of injections was predictive for PJI.

DISCUSSION: A cumulative amount of steroid or HA injections, if given more than 90 days prior to TKA, does not appear to increase the risk of PJI within 90 days postoperatively. Multiple intraarticular corticosteroid injections and HA injections may be safely administered before TKA, without increased risk for early PJI.