Minimally Displaced Humeral Lateral Condyle Fractures: Immobilize or Operate When Stability Is Unclear?

Either casting or in situ fixation (to prevent displacement) are recommended for minimally displaced pediatric lateral condyle fractures of indeterminate stability with ≤2 mm lateral displacement and narrowed fracture extension to the epiphyseal articular cartilage. This study compares casting only, acute prophylactic in situ pinning, and surgery if casting fails due to displacement.

In total, 738 fractures at a level 1 trauma center between 2008 and 2014 were reviewed. All fractures were assigned a Song classification and Song 2 fractures followed to union were analyzed. Worsening displacement was defined as an increase in Song stage. Patients were grouped per treatment: (1) cast only; (2) in situ pinning; or (3) closed or open reduction percutaneous pinning after displacement during attempted cast treatment.

In total, 139 fractures were included and 45 (32%) underwent surgery. Among 114 fractures intended for casting, only 20 (18%) displaced and needed surgery. This implies 82% of fractures prophylactically pinned in situ may have remained stable in a cast. On average, displaced fractures were noted 6.5 (2 to 13) days after presentation and required 1 extra clinic visit and week of immobilization without increased complications. Surgeons chose open reduction percutaneous pinning more often for displaced fractures.

Our data estimate 82% of Song 2 fractures never meaningfully displace in a cast. Meaningful displacements occur in <2 weeks. Benefits of prophylactic pinning include 1 less x-ray and clinic visit in exchange for a clinically insignificant lateral cortex reduction and inherent surgical risks. Compliance, surgical scheduling, and a higher rate of open reduction after displacement should influence early treatment decisions.

Level III.