title: Postoperative outcomes of initial varus versus initial valgus proximal humerus fracture: A systematic review and meta-analysis.
abstract: OBJECTIVE
  Our objective was to perform a systematic review of the literature and conduct a meta-analysis to investigate the effect of initial varus or valgus displacement of proximal humerus on the outcomes of patients with proximal humerus fractures treated with open reduction and internal fixation.
  
  
  METHODS
  In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement standards, we performed a systematic review. Electronic databases MEDLINE, EMBASE, CINAHL and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched to identify randomised and non-randomised studies comparing postoperative outcomes associated with initial varus versus initial valgus displacement of proximal humerus fracture. The Newcastle-Ottawa scale was used to assess the methodological quality and risk of bias of the selected studies. Fixed-effect or random-effects models were applied to calculate pooled outcome data.
  
  
  RESULTS
  We identified two retrospective cohort studies and one retrospective analysis of a prospective database, enrolling a total of 243 patients with proximal humerus fractures. Our analysis showed that initial varus displacement was associated with a higher risk of overall complication (RR 2.28, 95% CI 1.12-4.64,P= 0.02), screw penetration (RR 2.30, 95% CI 1.06-5.02,P= 0.04), varus displacement (RR 4.38, 95% CI 2.22-8.65,P< 0.0001), and reoperation (RR 3.01, 95% CI 1.80-5.03,P< 0.0001) compared to valgus displacement. There was no significant difference in avascular necrosis (RR 1.43, 95% CI 0.62-3.27,P= 0.40), infection (RR 1.49, 95% CI 0.46-4.84,P= 0.51), and non-union or malunion (RR 1.37, 95% CI 0.37-5.04,P= 0.64).
  
  
  CONCLUSIONS
  The best available evidence demonstrates that initial varus displacement of proximal humerus fractures is associated with higher risk of overall complication, screw penetration, varus displacement, and reoperation compared to initial valgus displacement. The best available evidence is not adequately robust to make definitive conclusions. Further high quality studies, that are adequately powered, are required to investigate the outcomes of initial varus and valgus displacement in specific fracture types.
  
  
  METHODS
  Level II.
authors.affiliation: Trauma and Orthopaedic Department, Queen's Medical Centre, Derby Road, Nottingham NG7 2UH, United Kingdom.
authors.forename: Mallikarjun Honnenahalli
authors.initials: MH
authors.lastname: Chandrappa
authors.affiliation: General Surgery Department, Royal Blackburn Hospital, Haslingden Rd, Blackburn BB2 3HH, United Kingdom.
authors.forename: Shahin
authors.initials: S
authors.lastname: Hajibandeh
authors.affiliation: General Surgery Department, Royal Blackburn Hospital, Haslingden Rd, Blackburn BB2 3HH, United Kingdom.
authors.forename: Shahab
authors.initials: S
authors.lastname: Hajibandeh
keywords: Humerus fracture; Open reduction and internal fixation; Valgus; Varus