Diagnosing Seronegative Periprosthetic Joint Infection After Total Hip and Knee Arthroplasties

Serum erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are used to screen for periprosthetic joint infection (PJI) of total hip arthroplasties (THAs) and total knee arthroplasties (TKAs). However, PJI may exist in the absence of elevated ESR and CRP. We aimed to report the incidence of seronegative PJIs in THAs and TKAs and the utility of arthrocentesis for PJI workup.

We identified 925 total joint arthroplasties (312 THAs, 613 TKAs) that had surgical management of a chronic PJI from 2013 to 2022 at a single institution. All cases met the 2011 Musculoskeletal Infection Society (MSIS) criteria for PJI. Seronegative PJI was defined as meeting the MSIS criteria for PJI with a preoperative ESR of less than 30 mm/hour and CRP of less than 10 mg/L. Hips and knees were analyzed separately.

Out of 925 chronic PJIs, 10% of THAs (n = 32) and 4% of TKAs (n = 24) were seronegative PJIs. Among these, 94% of hips and 92% of knees met more than one major MSIS criterion, with 94 and 92% of seronegative hips and knees, respectively, having at least two positive intraoperative cultures with the same organism. A positive culture from preoperative aspiration was obtained from 84 and 81% of seronegative hips and knees, respectively. The most common infecting organism overall was Staphylococcus epidermidis (25% of hips and 38% of knees), followed by Cutibacterium species (16%) for hips and polymicrobial infections (23%) for knees.

Serum ESR and CRP were normal in 10 and 6% of chronic hip and knee PJIs, respectively. An arthrocentesis before revision surgery was able to identify 84 and 81% of seronegative hip and knee PJIs, respectively, highlighting the importance of arthrocentesis prior to revision THA and TKA. Our findings suggest that serum ESR/CRP should not be utilized in isolation to definitively rule out PJI.

III (retrospective).