title: Rate of avascular necrosis and time to surgery in proximal humerus fractures.
abstract: OBJECTIVE
  Avascular necrosis (AVN) of the humeral head is a devastating complication of proximal humeral fracture (PHF) that often results in long-term morbidity for the patient. Rates of AVN depend on the number of fracture fragments and are highly variable. The literature suggests that timely stable and anatomic reduction may decrease the rate at which AVN develops after PHF. To our knowledge, there is no literature published investigating a temporal relationship between the timing of PHF fixation and rates of AVN.
  
  
  METHODS
  Operative records of one orthopedic trauma surgeon were used to identify patients that underwent open reduction internal fixation for PHF at our institution between 2007 and 2012. Radiographs at presentation were reviewed and used to classify the fractures into two, three or four parts. Date and time of the initial radiograph were recorded as were the date and time of available intra-operative fluoroscopic images. The time from presentation radiograph to operative fixation was calculated (hours). Available follow-up plain films were then reviewed and evaluated for the presence or absence of humeral head AVN.
  
  
  RESULTS
  Time to surgery (less than or greater than 72 h) and patient age did not correlate with development of AVN after PHF (p > 0.26). Notably, the number of fracture fragments did influence the rate of AVN identified in patients with PHF (p = 0.002).
  
  
  CONCLUSIONS
  Early operative intervention does not appear to decrease the rate of development of avascular necrosis after PHF.
authors.affiliation: Department of Orthopaedic Surgery, Memorial University of Newfoundland Health Sciences Center, 300 Prince Philip Drive, St. John's, NL, A1B 3V6, Canada. lori.anne.archer@gmail.com.
authors.forename: L A
authors.identifier: http://orcid.org/0000-0002-7767-8579
authors.initials: LA
authors.lastname: Archer
authors.affiliation: Department of Orthopaedic Surgery, Memorial University of Newfoundland Health Sciences Center, 300 Prince Philip Drive, St. John's, NL, A1B 3V6, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Furey
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001860:Bone Plates; D005500:Follow-Up Studies; D005593:Fracture Fixation, Internal / Q000379:methods; D017102:Fracture Healing; D006801:Humans; D008875:Middle Aged; D010020:Osteonecrosis / Q000000981:diagnostic imaging* / Q000601:surgery*; D011859:Radiography; D012189:Retrospective Studies; D012784:Shoulder Fractures / Q000000981:diagnostic imaging* / Q000601:surgery*; D016896:Treatment Outcome
keywords: Avascular necrosis; Open reduction internal fixation; Proximal humerus fracture; Timing of surgery