title: Management of deep postoperative shoulder infections: is there a role for open biopsy during staged treatment?
abstract: BACKGROUND
  Despite the gold standard treatment of 2-stage exchange arthroplasty, reinfection after periprosthetic shoulder infections and periarticular osteomyelitis can be as high as 37%. This study describes a protocol to detect persistent deep shoulder infection before revision arthroplasty.
  
  
  METHODS
  Patients who presented with periprosthetic shoulder infections and osteomyelitis after previous surgery were treated with a standardized protocol of irrigation and debridement (I&D), removal of implants, antibiotic cement spacer placement, and pathogen-directed antibiotic therapy for 6 weeks. After completion of antibiotics and resolution of clinical symptoms, specimens were obtained from an open biopsy performed in the operating room, followed by revision arthroplasty at a later date if final cultures were without evidence of infection. If evidence of infection persisted, then another course of I&D and antibiotic treatment was performed. American Shoulder and Elbow Surgeon scores were used to evaluate clinical outcomes.
  
  
  RESULTS
  Eighteen patients were included between 2005 and 2012. The most common pathogens isolated were Propionibacterium acnes (44%), Staphylococcus epidermidis (39%), and S aureus (22%). Four patients (22%) had evidence of persistent infection on specimens from open biopsy and required subsequent rounds of I&D before replantation. The infecting pathogen in 75% of patients with persistent infection was P acnes, and 38% of patients with P acnes infection had recurrence. Mean follow-up of 24 months showed no signs of recurrent infection in any patient and an average American Shoulder and Elbow Surgeon score of 71.
  
  
  CONCLUSIONS
  Despite prior staged treatment for deep postoperative shoulder infections, specimens obtained from open biopsy before replantation detected a persistent infection rate of 22% in all patients and 38% in patients with P acnes infection, which may indicate a role for this procedure in the prevention of recurrent infections.
authors: Department of Orthopaedic Surgery, University of California San Francisco, San Francisco, CA, USA.
authors: Alan L
authors: AL
authors: Zhang
authors: Department of Orthopaedic Surgery, University of California San Francisco, San Francisco, CA, USA.
authors: Brian T
authors: BT
authors: Feeley
authors: Department of Orthopaedic Surgery, University of California San Francisco, San Francisco, CA, USA.
authors: Brian S
authors: BS
authors: Schwartz
authors: Department of Orthopaedic Surgery, University of California San Francisco, San Francisco, CA, USA.
authors: Teddy T
authors: TT
authors: Chung
authors: Department of Orthopaedic Surgery, University of California San Francisco, San Francisco, CA, USA. Electronic address: MaBen@orthosurg.ucsf.edu.
authors: C Benjamin
authors: CB
authors: Ma
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000627:therapeutic use; D019643:Arthroplasty, Replacement / Q000009:adverse effects*; D001706:Biopsy; D001843:Bone Cements; D003646:Debridement; D020878:Device Removal; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010019:Osteomyelitis / Q000175:diagnosis / Q000382:microbiology / Q000628:therapy*; D016459:Prosthesis-Related Infections / Q000175:diagnosis* / Q000382:microbiology / Q000628:therapy*; D012086:Reoperation; D012189:Retrospective Studies; D012785:Shoulder Joint / Q000382:microbiology* / Q000601:surgery; D007507:Therapeutic Irrigation
chemical_list: D000900:Anti-Bacterial Agents; D001843:Bone Cements
keywords: Deep shoulder infection; open biopsy; recurrent infection; shoulder arthroplasty