Management of Propionibacterium acnes infection after shoulder surgery

Abstract

Propionibacterium acnes (P. acnes) is a gram-positive anaerobic bacillus commonly isolated from the flora of the face, chest, and axilla region. It has emerged as a major pathogen responsible for postoperative shoulder infections after both arthroscopy and arthroplasty procedures. Patients with P. acnes shoulder infection typically present with normal laboratory values (white blood cells (WBC), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP)) making diagnosis difficult. Several intraoperative tissue cultures should be obtained and cultured in both agar plate and broth in aerobic and anaerobic conditions for a minimum of 13 days to optimize the sensitivity and specificity to detect P. acnes. The utilization of intraoperative frozen sections to detect P. acnes infection is not reliable. Risk factors include male, cloudy synovial fluid, lucencies around the implant, and periprosthetic membrane formation. Managements include irrigation and debridement, single or two-staged revision, and intravenous antibiotics. Open biopsy prior to the final implantation (two-staged revision) may help detect persistent P. acnes infection. Penicillin and cephalosporins are effective against clinical P. acnes infection and biofilm in vitro. Combination antibiotic therapy with rifampin and daptomycin may further increase the clinical efficacy of treatment.

Figures

Fig. 1

Microscopic image of P. Acnes organism. Propionibacterium acnes by CDC-http://phil.cdc.gov ID#3083. Licensed under Public domain

Fig. 2

Arthroscopic evaluation and culture with biopsy for shoulder infection workup in a patient who presented with pain after total shoulder arthroplasty. a Diagnostic arthroscopy performed first with a dry scope technique. Cloudy synovial fluid was seen after the introduction of a 30° scope. b Spinal needle (18 gauge) was place anteriorly into the glenohumeral joint to aspirate the synovial fluid. c Multiple swab cultures were done through a 6-mm cannula placed anteriorly. d Glenoid component seen on the right and the humeral head on the left. A trochar was used to evaluate for glenoid loosening. Multiple tissue biopsies were taken using arthroscopic technique. Cultures were held for 14 days for P. Acnes