title: Treatment of displaced pediatric supracondylar humerus fracture patterns requiring medial fixation: a reliable and safer cross-pinning technique.
abstract: BACKGROUND
  Treatment of displaced Gartland type 3 supracondylar humerus fractures in children may include closed reduction and percutaneous pinning. The pin configuration may be all-lateral entry or cross-pin. Despite the improved stability possible with cross-pinning, there is an inherent iatrogenic risk to the ulnar nerve of about 6%. As medial fixation may be necessary for certain fracture patterns, this study was conducted to evaluate the risk of ulnar neuropathy using a technique here described and developed to minimize injury to this structure.
  
  
  METHODS
  A retrospective review was performed on all children treated for a supracondylar humerus fracture at our institution between 2003 and 2010. All the type 3 displaced fractures were placed into 2 groups: lateral-entry pinning and cross-pinning. The 2 groups were then compared for risk of ulnar nerve injury, and a post hoc power analysis was performed.
  
  
  RESULTS
  A total of 381 supracondylar humerus fractures met the inclusion criteria. Our cross-pinning technique was used in 187 (49%) of the children with a mean age of 5.8 years (range, 0.92 to 13.92 y). There were 4 ulnar nerve injuries in the entire cohort and 2 sustained as iatrogenic injuries in the cross-pinning group (1.1%). There was no significant difference between our 2 groups in regard to risk of ulnar nerve injury (P=0.24). There is a statistically significant lower risk of ulnar nerve injury in our cross-pinning technique than previously described techniques (P=0.0028), with a post hoc power analysis of 93%.
  
  
  CONCLUSIONS
  Despite the inherent risk for iatrogenic nerve injury with cross-pinning completely displaced supracondylar humerus fractures, there is often a need to use this technique to improve fixation and stability of the fracture. Our method of cross-pinning is safe and reproducible for providing fracture stability with a significant decrease in the risk of iatrogenic ulnar nerve injury (1 in 94) when a medial pin is required.
  
  
  METHODS
  Level III-therapeutic studies.
authors.affiliation: Department of Orthopaedic Surgery, Rady Children's Hospital and Health Center, San Diego, CA 92123, USA. ewedmonds@rchsd.org
authors.forename: Eric W
authors.initials: EW
authors.lastname: Edmonds
authors.forename: Joanna H
authors.initials: JH
authors.lastname: Roocroft
authors.forename: Scott J
authors.initials: SJ
authors.lastname: Mubarak
mesh_terms: D000293:Adolescent; D001858:Bone Nails; D002648:Child; D002675:Child, Preschool; D005260:Female; D005592:Fracture Fixation / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D006810:Humeral Fractures / Q000601:surgery*; D007223:Infant; D008297:Male; D011183:Postoperative Complications / Q000209:etiology; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012306:Risk; D016896:Treatment Outcome; D020424:Ulnar Neuropathies / Q000453:epidemiology / Q000209:etiology* / Q000517:prevention & control