Lateral humeral condyle fractures are common in children and there remains no consensus regarding treatment of minimally displaced injuries. Previous authors have recommended a variety of measures to assess fracture stability, including a manual stress test and an assessment of the soft tissue damage. This report attempts to assess stability using MRI. The goal was to determine the extent of the fracture line and correlate this finding with stability.
Sixteen patients were included in the study. Each patient underwent MR imaging within 10 days. Displacement greater than 3 mm was considered unacceptable and early surgery performed. Extension of the fracture line into the epiphysis was analyzed using the MR image. Fractures were considered “incomplete” when extension was not into the elbow joint, which left a cartilage hinge intact. “Complete” fractures extended into the joint. Ten patients had incomplete fractures and six patients had complete fractures. All ten of the incomplete and 2 of the complete had displacement less than 3 mm. Eleven maintained reduction during immobilization and one of the complete fractures displaced during casting and required surgical intervention. Four complete fractures were displaced greater than 3 mm and all underwent early ORIF.
This report adds additional information to our understanding of lateral condyle fractures. The status of the epiphysis cartilage may provide information regarding fracture stability. Disruption of the cartilage is an indicator of potential instability. However, the MRI is an expensive test that may require sedation and is probably best warranted in equivocal cases to assess stability.
Journal of Pediatric Orthopaedics