Background: A significant complication of prosthetic joint replacement is the development of a PJI. Therapy includes prolonged IV antibiotics (IVAB), usually delivered in the outpatient setting. Follow-up (FU) in this population can be difficult, particularly for the treating ID physician. We report our experience treating PJI in an ID POIC.
Methods: Retrospective chart review was conducted of patients (pts) with initial knee or hip PJI, who received ≥3 days of IVAB in 14 ID POICs from July 2015 to July 2017. Initial clinical success (ICS) was defined as no evidence of infection at completion of outpatient parenteral antimicrobial therapy (OPAT), although continued oral antibiotics were allowed. Available FU pts were assessed at 6 mo for recurrence and associated factors analyzed using Chi-squared and Fishers exact test.
Results: We evaluated 171 pts (122 knee, 49 hip) with a median age of 65 years (range 31-91) and 64% male. Infection occurred within 90 days of implant in 40% (25% within 30 days). Prostheses were retained in 109 pts (64%). 91% were hospitalized prior to OPAT for 4.7 median days, with the remainder treated from the community. Median length of OPAT was 37 days (range: 8-77). Cultures were positive in 154 pts with 122 Staphylococcus spp. pathogens (43% MSSA, 43% CoNS, 13% MRSA) in 112 pts. Most commonly prescribed IVABs were vancomycin (41%) and cefazolin (37%). ICS was achieved in 163 pts (95%), independent of prosthesis removal, with 119 (73%) continuing oral antibiotics post OPAT. Eight pts did not complete OPAT. Six-month FU to the ID physician was available for 97/163 pts completing therapy (60%). Of these, recurrence occurred in 22 pts (23%) at a median of 2.1 months (range 0.2-6). Risk factors for recurrence are noted below. Oral rifampin use with IVAB was associated with a significantly lower rate of recurrence in pts with staphylococcal PJI (p=0.004).
Conclusion: This real-world evaluation underscores the challenges of successful treatment of PJI. ICS was readily achieved (95%). High recurrence (23%) may be exaggerated by lower likelihood of FU in asymptomatic pts. Lack of improvement in 6-month cure with prosthesis removal merits additional inquiry. Although the group was small, adjunctive rifampin suggests improved outcomes in staphylococcal PJI.
B. S. Metzger,
J. R. Bernett, None
R. M. Mandel, None
R. C. Prokesch, None
C. T. Lo, None
T. C. Hardin, None
C. P. Schroeder, None
L. J. Van Anglen, Merck & Co.: Investigator , Research grant .