Orthopedic implants are frequently used to repair fractures and replace joints. The number of total joint replacements is high, with over 1 million total hip (THA) and total knee (TKA) arthroplasties performed in the United States each year (Maradit Kremers et al., 2015). While most joint arthroplasties are successful and significantly improve patient quality of life, a small proportion become infected (Kapadia et al., 2016).  Prosthetic joint infection (PJI) causes substantial morbidity and mortality, particularly among the elderly, and is difficult and costly to treat (Zhan et al., 2007). The historic “gold standard” treatment for PJI is a two-stage replacement, wherein the prosthesis is removed in one surgery and a new prosthesis is implanted in another after an extended course of antibiotics. This approach requires the patient to undergo two major procedures and spend considerable time without a functioning prosthesis, contributing to immobility and deconditioning. This option is difficult for frail or elderly patients and is associated with high medical costs (Fisman et al., 2001). 

In 1998, a novel method of orthopedic device treatment known as debridement, antibiotics, and implant retention (DAIR) was evaluated. This method utilized a unique antimicrobial approach: the administration of ciprofloxacin plus rifampin for 3-6 months, combined with a single surgical debridement. Eliminating a second surgical procedure and largely relying on oral antimicrobials reduces surgical risks and decreases costs. Current guidelines endorse DAIR with rifampin and a second antibiotic for patients diagnosed with PJI within approximately 30 days of prosthesis implantation who have a well-fixed implant without evidence of a sinus tract. Clinical trial data demonstrates that this approach is over 90% effective in patients who meet the guidelines. However, the effectiveness of this approach had not previously been studied in the VA population, where patients are older, frailer, and with more comorbidities. We conducted a retrospective review at the Minneapolis VA Health Care System to evaluate the management of PJI with DAIR combined with a rifampin-based regimen. 

The Minneapolis VA Healthcare System is a federally funded hospital which provides inpatient and outpatient care to U.S. Veterans. Research at the VA seeks to examine the effectiveness of medical treatments in their unique patient population.

At the VA I worked as a research assistant to Dr. Dimitri Drekonja, Chief of the Infectious Disease section. Dr. Drekonja and I designed a retrospective research study examining the efficacy of DAIR plus rifampin for treatment of PJI. In the project I analyzed over 700 patient charts across 20 years of data, prepared a manuscript for submission, and used my research to influence new guidelines surrounding PJI treatment at the VA. I also had the opportunity to shadow the Infectious Disease team in inpatient and outpatient settings, and interact with the population who my research would affect. 

Through our research, we found that DAIR followed by a short course of intravenous antibiotics and an oral regimen including rifampin is a reasonable option for veterans with acute staphylococcal orthopedic device infections. Consistent with previous research, we determined that patients with a well-placed prosthesis are especially well-suited for this treatment. We also identified ways to improve patient care through more consistent adherence to rifampin treatment guidelines. In my research I saw firsthand how socioeconomic status, access to care, and additional comorbidities influenced patients’ treatment outcomes. I realized how important preventative care, early diagnosis, and following treatment guidelines are to facilitating treatment success.

1. Fisman, D. N., Reilly, D. T., Karchmer, A. W., & Goldie, S. J. (2001). Clinical Effectiveness and Cost-Effectiveness of 2 Management Strategies for Infected Total Hip Arthroplasty in the Elderly. Clinical Infectious Diseases, 32(3), 419–430. https://doi.org/10.1086/318502

2. Kapadia, B. H., Berg, R. A., Daley, J. A., Fritz, J., Bhave, A., & Mont, M. A. (2016). Periprosthetic joint infection. The Lancet, 387(10016), 386–394. https://doi.org/10.1016/s0140-6736(14)61798-0

3. Maradit Kremers, H., Larson, D. R., Crowson, C. S., Kremers, W. K., Washington, R. E., Steiner, C. A., Jiranek, W. A., & Berry, D. J. (2015). Prevalence of Total Hip and Knee Replacement in the United States. The Journal of bone and joint surgery. American volume, 97(17), 1386–1397. https://doi.org/10.2106/JBJS.N.01141

4. Zhan, C., Kaczmarek, R., Loyo-Berrios, N., Sangl, J., & Bright, R. A. (2007). Incidence and Short-Term Outcomes of Primary and Revision Hip Replacement in the United States. The Journal of Bone & Joint Surgery, 89(3), 526–533. https://doi.org/10.2106/jbjs.f.00952

Image Credits: Minneapolis VA Medical Center