title: Percutaneous screw fixation promotes healing of lateral condyle nonunion in children.
abstract: BACKGROUND
  This retrospective study examined whether pediatric lateral condyle nonunions could be successfully managed by percutaneous screw fixation. We report the outcome of this minimally invasive technique avoiding open reduction and bone grafting associated with the risk of avascular necrosis (AVN), infection, and stiffness.
  
  
  METHODS
  The hospital radiology database was searched between 1998 and 2008. This identified 16 consecutive patients aged 2 to 10 years, with lateral condyle nonunions treated with percutaneous screw fixation. We assessed clinical and radiographic outcomes from presentation to final follow-up. Potential risk factors for recalcitrant nonunion were identified. Categorical variables are presented as proportions and percentages. Continuous variables were assessed for normality with the d'Agostino-Pearson test. Normally distributed variables are presented as means with 1 SD. Non-normally distributed data are presented as medians with interquartile range.
  
  
  RESULTS
  Outcome was defined as successful if radiologic and clinical union was achieved. Twelve patients (75%) united after surgery, at a mean of 16.2 weeks (±6.74). Four (25%) failed to unite. The failures presented with nonunion later (median of 225.5 wk from initial injury). This was significantly different (P=0.039) from presentation in the successful group (median time 15.7 wk).Median age at injury was 5.1 years (range, 3.2 to 7.2) in the successful and 2.8 years (range, 2.1 to 4.7) in the unsuccessful group (P=0.18). Overall, mean time from nonunion diagnosis to percutaneous surgery was 5.2 weeks (±4.11). Forty-four percent had implant removal once union was achieved and no cases of AVN were reported.
  
  
  CONCLUSIONS
  We demonstrate this technique to be successful in nonunions addressed within 16 weeks from initial injury to diagnosis. Our 4 failures occurred in nonunions diagnosed >31 weeks from the injury (31, 68, 383, 427 wk). All had been managed nonoperatively as their primary treatment plan.Percutaneous fixation is feasible and safe. Patients not achieving union were diagnosed after a greater delay. There was a trend toward successfully treated patients being younger. There were no cases of AVN, infection, or elbow stiffness.
  
  
  METHODS
  Level 4.
authors.affiliation: Division of Orthopaedic Surgery, The Hospital for Sick Children, Toronto, ON, Canada.
authors.forename: Dominique M
authors.initials: DM
authors.lastname: Knight
authors.forename: Cristina
authors.initials: C
authors.lastname: Alves
authors.forename: Benjamin
authors.initials: B
authors.lastname: Alman
authors.forename: Andrew
authors.initials: A
authors.lastname: Howard
mesh_terms: D001863:Bone Screws; D002648:Child; D002675:Child, Preschool; D004551:Elbow Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D005260:Female; D005592:Fracture Fixation; D017102:Fracture Healing; D005599:Fractures, Ununited / Q000000981:diagnostic imaging / Q000601:surgery*; D006801:Humans; D006810:Humeral Fractures / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D019060:Minimally Invasive Surgical Procedures; D011859:Radiography; D012189:Retrospective Studies; D000092464:Elbow Injuries