Abstract
Background. Culture-negative (CN) prosthetic joint infection (PJI) has not been well studied. We performed a retrospective cohort study to define the demographic characteristics and determine the outcome of patients with CN PJI.
Methods. All cases of CN total hip arthroplasty and total knee arthroplasty infections (using a strict case definition) treated at our institution from January 1990 through December 1999 were analyzed. Kaplan-Meier survival methods were used to determine the cumulative probability of success.
Results. Of 897 episodes of PJI during the study period, 60 (7%) occurred in patients for whom this was the initial episode of CN PJI. The median age of the cohort was 69 years (range, 36–87 years). Patients had received a prior course of antimicrobial therapy in 32 (53%) of 60 episodes. Of the 60 episodes, 34 (57%), 12 (20%), and 8 (13%) were treated with 2-stage exchange, debridement and retention, and permanent resection arthroplasty, respectively. The median duration of parenteral antimicrobial therapy was 28 days (range, 0–88 days). Forty-nine (82%) of 60 episodes were treated with a cephalosporin. The 5-year estimate of survival free of treatment failure was 94% (95% confidence interval, 85%–100%) for patients treated with 2-stage exchange and 71% (95% confidence interval, 44%–100%) for patients treated with debridement and retention.
Conclusions. CN PJI occurs infrequently at our institution. Prior use of antimicrobial therapy is common among patients with CN PJI. CN PJI treated at our institution is associated with a rate of favorable outcome that is comparable to that associated with PJI due to known bacterial pathogens.
Publication
Clinical Infectious Diseases
Notes
The authors retrospectively examined patients with Culture-Negative Prosthetic Joint Infections (CN PJI) who underwent total hip or knee arthroplasty at the Mayo Clinic between 1990 and 1999. The study aimed to estimate the probability of treatment failure in these patients and identify variables associated with it.
Key findings:
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Definition of CN PJI: CN PJI was diagnosed based on clinical signs such as purulence around the prosthesis, acute inflammation in periprosthetic tissue, or a sinus tract connecting to the prosthesis. In these cases, standard cultures showed no microbial growth.
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Patients and Demographics: The study included 60 episodes of CN PJI in 59 patients. The median age at diagnosis was 70 years, with a range of 36 to 87 years. Most patients were female (47%), and 55% of CN PJI cases were related to total knee arthroplasty (TKA).
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Clinical Presentation: The median time from prosthesis implantation to CN PJI diagnosis was 1,269 days, and the median duration of symptoms prior to diagnosis was 103 days. Some patients had a fever (22%) or a sinus tract (10%). Histopathological examination of periprosthetic tissue indicated acute inflammation in 78% of cases.
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Microbiologic Examination: Multiple specimens were submitted for aerobic and anaerobic cultures, but none revealed microbial growth. Fungal and mycobacterial cultures were also negative.
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Treatment Modalities: The primary treatments for CN PJI were two-stage exchange (57% of cases), debridement and retention (20%), and permanent resection arthroplasty (13%).
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Outcome and Risk Factors: The overall 5-year survival free of treatment failure for CN PJI was 82%. Two-stage exchange had the best outcome, with a 5-year survival rate of 94%. Patients with acute inflammation in periprosthetic tissue had better outcomes than those without. Patients who received prior antimicrobial therapy had a higher risk of treatment failure.
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Medical Therapy: The choice of systemic antimicrobial therapy was determined based on various factors, including the spectrum of activity of prior antimicrobial therapy, local antimicrobial therapy, resistance patterns, patient allergies, intolerances, and comorbidities.
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Optimal Surgical Therapy: The choice of surgical therapy depended on multiple factors, including patient characteristics, prosthesis age, duration of symptoms, and operative risks.
In conclusion, the study found that CN PJI can have outcomes similar to PJI caused by known pathogens, and many cases may result from prior antimicrobial therapy. Two-stage exchange was associated with the best outcomes, but the choice of medical and surgical therapy should be individualized based on patient factors. The study suggests that CN PJI may be due to biofilm-producing microorganisms, and further research is needed to confirm this hypothesis.
Level of evidence: Low (retrospective)
Citation
1.
Berbari EF, Marculescu C, Sia I, et al. Culture-Negative Prosthetic Joint Infection. Clinical Infectious Diseases. 2007;45(9):1113-1119.