798. Propionibacterium acnes Prosthetic Joint Infections 2000-2012: Potential Role of Nonoperative Management
Session: Poster Abstract Session: Bone and Joint
Friday, October 4, 2013
Room: The Moscone Center: Poster Hall C
Posters
  • 798_IDWPOSTER.pdf (314.5 kB)
  • Background: Prosthetic joint infections (PJIs) continue to complicate joint arthroplasties, with significant adverse clinical and economic consequences for the aging U.S. population. Propionibacterium acnes is increasingly recognized as an important PJI pathogen. However, limited data exist regarding the diagnosis and management of PJIs with this low virulence, commensal organism.

    Methods: We conducted a retrospective chart review of P. acnes PJIs at an academic center in Baltimore, Maryland from 2000 to 2012. We examined clinical and microbiologic parameters before and after institution of prolonged P. acnes culture incubation protocols in January 2009.

    Results: We identified 29 cases of P. acnes PJIs; 3 in 2000-2008 and 26 in 2009-2012. The median age was 61 (range 33-82), 90% male, and 93% white. Affected sites included the shoulder (23), knee (5), and hip (1). All patients presented with pain. Fever was documented in 1 case. Of all cases, 18% occurred in the early postsurgical period (<3 months), 25% were delayed (3-24 months) and 57% presented late (>24 months post procedure). ESR was elevated in 10 of 17 (59%) and CRP was elevated in 9 of 18 (50%) cases. The median time to culture positivity was 4 days (range 3-14). All tested isolates were susceptible to penicillin, piperacillin/tazobactam, ertapenem, moxifloxacin, and rifampin. Clindamycin susceptibility was noted in 16 of 18 (89%) isolates. All tested isolates were resistant to metronidazole. The MIC range for vancomycin was 0.12-1 µg/ml and for minocycline 0.03-0.25 µg/ml. Treatment primarily entailed antibiotic therapy with or without a surgical approach. Median follow up was 17 months. Of 6 antibiotic-only treated cases, 5 (83%) had a favorable clinical outcome, compared to 12 of 18 (66%) cases with a combined antibiotic-surgical approach.

    Conclusion: The number of P. acnes PJI diagnoses has notably increased with prolonged incubation and anaerobic culture methods. Inflammation-associated markers are elevated in a significant proportion but not all cases. Isolates have maintained sensitivity to β-lactams. Compared to traditional combined antibiotic-surgical approaches, antibiotic-only approaches may be similarly successful in selected cases.

    Damani Piggott, MD, PhD, Yvonne Higgins, MS, Michael T. Melia, MD, Brandon Ellis, BS, Karen Carroll, MD, Edward Mcfarland, MD and Paul Auwaerter, MD, MBA, Johns Hopkins University, Baltimore, MD

    Disclosures:

    D. Piggott, None

    Y. Higgins, None

    M. T. Melia, None

    B. Ellis, None

    K. Carroll, Illumingene: Grant Investigator, Research support
    BioFire Inc,: Grant Investigator, Research support
    Nanosphere, Inc.: Research Contractor, Research grant
    Quidel, Inc. : Scientific Advisor, Consulting fee
    AdvanDX, Inc: Research Contractor, Research support

    E. Mcfarland, None

    P. Auwaerter, None

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