Reliability of radiological measurements and treatment recommendations of displaced paediatric humeral medial epicondyle fractures

There are conflicting recommendations regarding the amount of displacement necessitating stabilization of paediatric humeral medial epicondyle fractures. Our aim was to assess the reliability of the measurements of the displacement and the treatment recommendations of these fractures. The maximum displacement of 57 children with displaced humeral medial epicondyle fractures was analyzed on radiographs by six raters (4 paediatric surgeons, 2 paediatric radiologists) at two time points. In addition, the four surgeons recorded their treatment recommendation. Intraobserver and interobserver reliability were calculated with intraclass correlation coefficients (ICC) and Kappa values. The ICC for the intraobserver reliability ranged between 0.67 and 0.93. The raters disagreed with their own measurements between 8.8% and 28.1%. The ICC for the interobserver reliability of all six raters was 0.90 for measurement 1 and 0.93 for measurement 2. All six raters disagreed (difference > 2mm) in 93% of the cases in measurement 1 and in 91.2%in measurement 2. Treatment recommendations of the four paediatric surgeons between the two time points differed in 5.3% to 28.1% of the cases. Furthermore, the treatment recommendations were concordant in 24 cases (42%) at time point 1 and 32 cases (56.1%) at time point 2. In displaced paediatric medial epicondyle fractures, disagreement regarding measurement of displacement and recommendation for treatment is high. Validated and standardized measurement tools and a clear threshold for operative fixation of displaced medial epicondyle fractures are needed.