title: Intraoperative intra-articular injection of gentamicin: will it decrease the risk of infection in total shoulder arthroplasty?
abstract: BACKGROUND
  Deep infection is a debilitating complication after shoulder arthroplasty. Intra-articular injection of antibiotic can give a higher concentration compared with intravenous administration. We hypothesized that a group of patients given an intra-articular, intraoperative injection of gentamicin would report a lower infection rate than a group without local antibiotics.
  
  
  METHODS
  Between 2005 and 2011, the senior author performed 507 shoulder arthroplasties. We retrospectively reviewed all of those cases. All patients were administered systemic prophylactic antibiotics. Beginning in June 2007, patients were also injected with 160 mg of gentamicin in the glenohumeral joint at the end of their surgery. Patient records were examined for preexisting medical conditions, type of surgery, and presence of infection. Patients receiving surgery before 2007 were compared with those after to determine the effect of prophylactic gentamicin administration in preventing deep infection associated with surgery. All patients were observed for a minimum of 1 year.
  
  
  RESULTS
  Of the 507 surgeries, 164 were performed before 2007 (without intra-articular injection of gentamicin; group A) and 343 were performed with addition of gentamicin (group B). In group A, 5 patients presented with infection (3.0%) compared with 1 in group B (0.29%). The gender, mean age, mean body mass index, and prevalence of comorbidities were similar between the groups.
  
  
  CONCLUSIONS
  The data from this study support the conclusion that intra-articular intraoperative gentamicin administration may reduce postoperative infection.
authors.affiliation: Anderson Orthopedic Clinic, Alexandria, VA, USA; Department of Medicine, Georgetown University, Washington, DC, USA; INOVA Hospital, Alexandria, VA, USA.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Lovallo
authors.affiliation: Nirschl Orthopedic Center, Arlington, VA, USA.
authors.forename: Jarrett
authors.initials: J
authors.lastname: Helming
authors.affiliation: Nirschl Orthopedic Center, Arlington, VA, USA.
authors.forename: S Mehdi
authors.initials: SM
authors.lastname: Jafari
authors.affiliation: Nirschl Orthopedic Center, Arlington, VA, USA.
authors.forename: Afia
authors.initials: A
authors.lastname: Owusu-Forfie
authors.affiliation: Nirschl Orthopedic Center, Arlington, VA, USA; Department of Physical Therapy, Marymount University, Arlington, VA, USA. Electronic address: Skye.donovan@marymount.edu.
authors.forename: Skye
authors.initials: S
authors.lastname: Donovan
authors.affiliation: Nirschl Orthopedic Center, Arlington, VA, USA.
authors.forename: Christopher
authors.initials: C
authors.lastname: Minnock
authors.affiliation: University of Maryland, Baltimore, MD, USA.
authors.forename: Farshad
authors.initials: F
authors.lastname: Adib
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D019643:Arthroplasty, Replacement / Q000009:adverse effects*; D005260:Female; D005839:Gentamicins / Q000008:administration & dosage*; D006801:Humans; D007270:Injections, Intra-Articular; D007430:Intraoperative Care; D007592:Joint Diseases / Q000601:surgery; D008297:Male; D008875:Middle Aged; D016459:Prosthesis-Related Infections / Q000517:prevention & control*; D012086:Reoperation; D012189:Retrospective Studies; D012785:Shoulder Joint / Q000601:surgery*; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D005839:Gentamicins
keywords: Shoulder; antibiotics; arthroplasty; gentamicin; infection; intra-articular