IOA 2022

Intra-articular Corticosteroid Injections into a Pre-existing Total Knee Arthroplasty are Associated with an Increased Risk of Periprosthetic Joint Infection and Revision

Caleb Durst Kevin Rezzadeh Sean Rajaee Andrew Spitzer
Department of Orthopaedic Surgery, Cedars-Sinai Medical Center, USA

Introduction:
Periprosthetic Joint Infection (PJI) following total knee arthroplasty (TKA) is a devastating complication. Intra-articular corticosteroid (IACS) injections are occasionally administered to treat painful TKAs, but associated risks are unclear. This study addresses the risk of PJI and revision following IACS injections into a pre-existing TKA.

Methods:
Patients aged 40-100 undergoing primary TKA between 2015–2020 were identified using the PearlDiver database. Those receiving any ipsilateral knee injection within 3 months prior to, or a hyaluronic acid injection within 5 years following TKA were excluded. CPT and ICD-10 codes, used in tandem, identified TKAs followed by an ipsilateral IACS injection. Risks of PJI and revision within 5 years were compared between the IACS group and a control group without injection.

Results:
Of 905,825 TKAs, 30,726 (3.39%) received ipsilateral IACS injections postoperatively after an average of 435.45 days (Range: 2–2,561). IACS patients were categorized according to number of injections received(Table 1). The odds of infection were 1.71 greater amongst those receiving IACS (IACS: 2.37% [95% CI: 2.20%-2.54%] vs Control: 1.40% [1.37%-1.42%], p<0.01)(Figure 1). Infection risk was increased with each incremental injection: 1-IACS (OR: 1.49; rate: 2.25% [1.84-2.30%]), 2-IACS (OR: 2.43; rate; 3.33% [2.75%-3.91%]), >3-IACS (OR: 3.83; rate: 5.15% [95% CI: 4.01%-6.30]) (p<0.05)(Figure 2). The odds of revision were 3.54 greater amongst those receiving IACS (IACS: 2.79% [95% CI: 2.61%-2.98%] vs Control: 0.81% [0.79%-0.82%], p<0.01). Revision risk was also increased with each incremental injection: 1-IACS [OR: 2.84: rate; 2.26% [95% CI: 2.07%-2.44%]), 2-IACS (OR: 6.25: rate; 4.83% [4.14%-5.53%]), >3-IACS (OR: 9.51: rate; 7.17% [5.84%-8.51%]) (p<0.05)(Figure 3).

Discussion:
IACS injections following TKA were associated with increased risk of PJI and revision within 5 years of primary TKA. Before injecting a painful TKA with IACS, physician and patient should consider the potential deleterious impact on PJI and revision.