Determining the stability of minimally displaced lateral humeral condyle fractures in children: ultrasound is better than arthrography

BACKGROUND: Evaluating of the articular cartilage status of the distal humeral epiphysis is difficult. Ultrasound imaging of the elbow is increasingly being used to confirm the integrity of the articular cartilage of minimally displaced lateral humeral condyle fractures in children with minimally displaced fractures. The aims of this study were to assess the correlations between ultrasound and arthrography findings for predicting the integrity of the cartilage hinge and to describe the utility of ultrasound in determining the need for pre-treatment. METHODS: Thirty-nine patients with minimally displaced lateral humeral condyle fractures who underwent ultrasound and arthrography examinations before surgery from May 2018 to December 2019 were included in this study. Ultrasound and arthrography predictors of the cartilage hinge status were independently measured. The ultrasound and arthrography results were compared. RESULTS: The mean displacement of the fractures was 3.1 mm (range, 2.0~5.0 mm). Arthrography showed incomplete fractures in 24 patients (61.5%) and complete fractures in 15 patients (38.5%). Ultrasound showed incomplete fractures in 25 patients (64.1%) and complete fractures in 14 patients (35.9%). The ultrasound and arthrography results of the integrity of the articular surface were consistent in 92.3% of the cases, including 23 that were predicted to have an intact articular surface and 13 that were predicted to have an incongruity articular surface. There was no correlation between the displacement and the fracture appearing complete on the ultrasound scan. The Pearson coefficient between ultrasound and arthrography for assessing the integrity of the articular surface was 0.837. CONCLUSIONS: Ultrasound and arthrography assessments of the integrity of the cartilage hinge status appear to be highly consistent. Ultrasound can be used as a complementary tool with arthrography to predict the integrity of the cartilage hinge status in children with minimally displaced lateral humeral condyle fractures. LEVEL OF EVIDENCE: Prospective study; level II.