Why not borrow a successful approach from another field? That is what investigators from Massachusetts General Hospital thought when they began research on the use of erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) ratio as a marker for predicting infection resolution in patients with periprosthetic joint infections (PJI) after debridement, antibiotics and implant retention (DAIR).
Their study, “Elevated ESR/CRP Ratio is associated with re-infection following debridement, antibiotics and implant retention in chronic periprosthetic joint infections,” appears in the June 9, 2020 edition of The Journal of Arthroplasty.
Co-author Kwon Young-Min, M.D., Ph.D., program director of the Adult Reconstructive Surgery Fellowship Program at Mass General, explained the origins of the study to OTW: “Recent efforts have focused on using the ratio between erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) to illustrate success in non-orthopaedic literature distinguishing infection from flare in systemic lupus erythematosus patients presenting with fever. However, there is a limited data investigating the diagnostic potential of erythrocyte sedimentation rate to C-reactive protein ratio (ECR) in the setting of periprosthetic joint infection (PJI) in patients with total hip [THA] and knee joint arthroplasty [TKA].”
“As debridement, antibiotics and implant retention (DAIR) is used as surgical treatment option for acute and chronic periprosthetic joint infections, with success rates of debridement, antibiotics and implant retention varying widely, the focus of our study was to evaluate the diagnostic accuracy of ECR in predicting postoperative reinfection in THA and TKA patients that underwent debridement, antibiotics and implant retention for periprosthetic joint infection.”
The authors performed a retrospective review of 179 consecutive patients who had debridement, antibiotics and implant retention surgery after periprosthetic joint infections. Participants were stratified as: 1) acute periprosthetic joint infections, 2) acute hematogenous periprosthetic joint infections, and 3) chronic periprosthetic joint infections.
A Difference in Acute And Chronic Infections
Dr. Kwon explained to OTW that the study demonstrated “an elevated erythrocyte sedimentation rate to CRP ratio (ECR) was associated with an increased reinfection risk in patients that underwent debridement, antibiotics and implant retention for chronic periprosthetic joint infections (p=0.04).”
“There was no association between an elevated erythrocyte sedimentation rate to C-reactive protein ratio and an increased reinfection risk in patients that underwent DAIR for acute infection (p=0.70).”
“Given that previous literature showed high failure rates in patients with chronic infections following debridement, antibiotics and implant retention, the findings of this study have the potential to assist in clinical decision-making for surgeons.”
“Patients with acute periprosthetic joint infections have shown good outcomes following debridement, antibiotics and implant retention, with chronic infections demonstrating increased failure rates. The findings of our study demonstrate that an elevated erythrocyte sedimentation rate to CRP ratio has the potential to predict increased reinfection risks in patients that underwent debridement, antibiotics and implant retention for chronic PJI, thus the erythrocyte sedimentation rate to C-reactive protein ratio may clinically be used to assist in surgical decision-making for patients that are due to undergo a debridement, antibiotics and implant retention procedure for chronic PJI in order to reduce post-operative reinfection rates.”

