What Are the Long-Term Outcomes of 2-Stage Exchange for Chronic PJI?
Dr. Beau Kildow and Dr. Bryan Springer answer ICJR’s questions about their multicenter study investigating eradication, reinfection, and mortality rates among knee and hip arthroplasty patients who were at least 5 years out from 2-stage exchange for periprosthetic joint infection.
ICJR: What question did you and your co-authors want to answer with this study?
Beau J. Kildow, MD: Our goal was to evaluate short- and long-term outcomes following 2-stage exchange arthroplasty for treatment of chronic periprosthetic joint infection (PJI). Specifically, we wanted to quantify patient outcomes at more than 5 years out from surgery, as the data on this topic are currently minimal.
We know that patients still experience complications and reinfections after their infections had been considered “eradicated.” With this study, we hoped to identify factors that correlate to long-term reinfection, which may help improve treatment strategies for chronic PJI. We included patients from 3 large tertiary referral centers that commonly treat chronic PJI – OrthoCarolina, University of Nebraska Medical Center, and University of Iowa Medical Center – to increase sample size as well as decrease treatment pathway variation.
ICJR: What did you conclude about outcomes of 2-stage revision for chronic PJI?
Dr. Kildow: We performed a retrospective review of all knee and hip arthroplasty patients who were diagnosed with a chronic PJI and who underwent a planned 2-stage exchange procedure at 3 large institutions. We found relatively high infection eradication rates, in addition to high mortality rates. We concluded that 2-stage exchange remains the gold standard for managing knee and hip arthroplasty patients with chronic PJI.
However, despite relatively good infection control, mortality and complication rates were high, especially in the long term. Patient whose health was more compromised – ie, more major comorbidities – and those who had antibiotic-resistant organisms were more likely to experience reinfection.
ICJR: How did you reach your conclusions? What was your study cohort and what did you find with your analysis?
Dr. Kildow: Among our 3 institutions, we identified 237 knees and 221 hips that underwent 2-stage exchange for PJI between 1990 and 2015, with average follow-up of 5.21 and 6.14 years, respectively. For the knee patients, we found that:
- The overall infection eradication rate was 81% and the overall mortality rate was 28%.
- Infection recurrence was 11%, with mortality of 33%, among the 118 knees with more than 5 years of follow-up.
- The calculated survival rate at 5 years was 85%, with cumulative risk of reinfection of 17%.
- Coagulase-negative staphylococcus was the most prevalent organism (19%), while Streptococcus species was associated with the highest failure rate (47%).
For hip patients, we found that:
- The overall infection eradication rate was 88% and the overall mortality rate was 41%.
- The reinfection rate was 8.5%, with a mortality rate of 41%, among the 129 hips with more than 5 years of follow-up.
- The calculated survival rate at 5 years was 80%, with cumulative risk of reinfection of 9%.
- Coagulase-negative Staphylococcus was the most prevalent organism (19%) and had the highest success rate (95%), while methicillin-resistant Staphylococcus aureus was associated with the highest failure rate (21%).
In hip patients, polymicrobial and antibiotic-resistant organisms were identified as risk factors for failure. No risk factors were identified in the knee patients. Patients in both groups averaged 3 major comorbidities.
ICJR: Why are your findings significant for clinical practice?
Bryan D. Springer, MD: This is one of the few studies – and the only multi-institutional study – that has evaluated long-term outcomes following 2-stage exchange for chronic PJI in knee and hip arthroplasty patients. Our overall findings regarding infection eradication, complications, and mortality parallel those of other reports. Two of our findings should be emphasized:
- The 5-year chronic PJI survival rates (about 80%) are similar to overall cancer survival rates (78%) and much higher than breast (90%) and prostate (98%) cancer.
- About 10% of reinfections were reported in patients who were more than 5 years out from 2-stage exchange.
These findings will help surgeons counsel patients on expected outcomes following treatment of chronic PJI with 2-stage exchange. They also further highlight the need for research and innovation in the treatment of PJI.
Kildow BJ, Springer BD, Brown TS, Lyden E, Fehring TK, Garvin KL. Results of Two-Stage Revision for Chronic Periprosthetic Joint Infection with Minimum 5-Year Follow Up: A Multicenter Study (Paper 005). Presented at the 2021 Annual Meeting of the American Academy of Orthopaedic Surgeons, August 31-September 3, San Diego, California.
About the Experts
Beau J. Kildow, MD, is from the University of Nebraska Medical Center in Omaha, where he specializes in adult reconstructive surgery.
Bryan D. Springer, MD, is the Adult Reconstruction Fellowship Director at the OrthoCarolina Hip and Knee Center in Charlotte, North Carolina. He is also a Professor in the Department of Orthopedic Surgery at the Atrium Musculoskeletal Institute.
Disclosures: Dr. Kildow has no disclosures relevant to this article. Dr. Springer has disclosed that he receives royalties from and is a paid consultant for OsteoRemedies and Stryker; that he is a paid consultant for ConvaTec; and that he receives other financial or material support from Joint Purification Systems.