title: Is previous nonarthroplasty surgery a risk factor for periprosthetic infection in primary shoulder arthroplasty?
abstract: BACKGROUND
  The purpose of this study was to determine the risk of periprosthetic infection after primary shoulder arthroplasty (SA) in patients undergoing previous nonarthroplasty shoulder surgery compared with those without previous surgery.
  
  
  METHODS
  All patients undergoing primary SA at our institution between 1970 and 2012 were included in this study. The cohort consisted of 4577 patients treated with 2890 total SAs, 1233 hemiarthroplasties, and 454 reverse SAs; 813 (18%) patients had undergone prior nonarthroplasty shoulder surgery on the operative side. Patients with and without previous surgery were compared for postoperative periprosthetic infection. Univariate and multivariable analyses were used.
  
  
  RESULTS
  Deep postoperative infection of the shoulder was diagnosed in 68 patients (1.49%). Of the 813 patients who had undergone previous surgery, 20 (2.46%) developed a deep postoperative infection. However, of the 3764 patients who did not have previous shoulder surgery, 48 patients (1.28%) sustained deep shoulder infection. This difference was significant in both the univariate (P = .0094) and multivariate analyses (P = .0390). In addition, older age and female gender were significantly associated with a lower risk of deep postoperative infection (P = .0150 and P = .0074, respectively). A higher number of previous surgeries was also significantly associated with an increased risk of deep postoperative infection (P = .0272).
  
  
  CONCLUSIONS
  The risk of infection after primary SA is significantly higher in patients with a history of prior non-arthroplasty-related surgery. This finding should be discussed with the patients before their surgery, and potential preoperative and intraoperative workup should be undertaken to identify at-risk patients.
authors.affiliation: Department of Orthopaedic Surgery, Mayo Clinic, Rochester, MN, USA.
authors.forename: Jean-David
authors.initials: JD
authors.lastname: Werthel
authors.affiliation: Department of Orthopaedic Surgery, Mayo Clinic, Rochester, MN, USA.
authors.forename: Taku
authors.initials: T
authors.lastname: Hatta
authors.affiliation: Department of Orthopaedic Surgery, Mayo Clinic, Rochester, MN, USA.
authors.forename: Bradley
authors.initials: B
authors.lastname: Schoch
authors.affiliation: Department of Orthopaedic Surgery, Mayo Clinic, Rochester, MN, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Cofield
authors.affiliation: Department of Orthopaedic Surgery, Mayo Clinic, Rochester, MN, USA.
authors.forename: John W
authors.initials: JW
authors.lastname: Sperling
authors.affiliation: Department of Orthopaedic Surgery, Mayo Clinic, Rochester, MN, USA. Electronic address: elhassan.bassem@mayo.edu.
authors.forename: Bassem T
authors.initials: BT
authors.lastname: Elhassan
mesh_terms: D000368:Aged; D000072228:Arthroplasty, Replacement, Shoulder; D005260:Female; D062785:Hemiarthroplasty; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D016459:Prosthesis-Related Infections / Q000453:epidemiology*; D012086:Reoperation; D012189:Retrospective Studies; D012307:Risk Factors; D012785:Shoulder Joint / Q000601:surgery*; D013530:Surgical Wound Infection / Q000453:epidemiology*
keywords: Shoulder arthroplasty; periprosthetic infection; primary procedure; reoperation; risk factors; rotator cuff repair