The Use of Preoperative CRP and ESR as Predictive Markers of Prosthetic Joint Infection in Primary Total Hip and Knee Arthroplasty

Abstract

Research Question: Do patients who undergo primary total hip arthroplasty (THA) or total knee arthroplasty (TKA) with elevated pre-operative C-reactive protein (CRP) and/or erythrocyte sedimentation rate (ESR) produce a higher incidence of post-operative periprosthetic joint infection (PJI), compared to THA and TKA patients that had normal pre-op labs? Further, what proportion of patients that developed PJI post-operatively had elevations in only CRP, only ESR, or both CRP and ESR? Lastly, we will investigate whether patients had pre-operative elevations in CRP and/or ESR due to the presence of a modifiable risk factor, such as an acute infection or inflammation. How did such conditions correlate with PJI development when compared to patients with non-modifiable risk factors (age, sex, chronic disease)?

Background and Significance: CRP and ESR are commonly utilized indicators of inflammation in the diagnosis and management of PJI among patients undergoing THA and TKA. The frequency of these surgeries is expected to increase significantly, with projections indicating a rise from 400,000 THAs and 700,000 TKAs annually to 635,000 THAs and 1,260,000 TKAs by 2030. PJI poses a notable challenge, contributing to 20% of revision THA cases and 25% of revision TKA cases. The economic burden of PJI is substantial, estimated to reach $753.4 million for THA and $1.1 billion for TKA by 2030. Given the transition to value-based healthcare, optimizing patients before surgery is paramount. This study aimed to evaluate the association between preoperative CRP/ESR levels and the subsequent development of PJI following primary THA and TKA, as well as to identify modifiable and non-modifiable risk factors among patients exhibiting elevated preoperative inflammatory markers.

Materials and Methods: retrospective review was conducted on 806 patients from a single healthcare facility who had undergone either THA (n=291) or TKA (n=515). As part of the preoperative assessment, CRP and ESR levels were measured for all patients. Data regarding patient demographics, medical conditions, and incidences of PJI were collected. A CRP value greater than 0.3 mg/dL and an ESR value exceeding 30 mm/hr were considered positive indicators.

Results: Our study revealed no statistically significant correlation between pre-operative CRP or ESR and PJI. However, it is worth mentioning that a greater percentage of patients diagnosed with PJI exhibited elevated preoperative CRP levels (70.6%) compared to PJI cases with normal CRP levels (29.4%).

Conclusion: This study did not validate the use of preoperative CRP and ESR as reliable predictors of PJI in primary THA and TKA. However, it offers valuable quantitative data on the prevalence of elevated preoperative CRP and ESR levels in all patients undergoing THA and TKA, with a significant portion having modifiable risk factors. Given that a significant number of patients with elevated CRP and ESR levels did not develop PJI, we do not advise cancellation of THA and TKA unless there are obvious modifiable risk factors significantly increasing the risk of PJI.