A New Radiological Parameter in Pediatric Lateral Condyle Fractures: How Effective Is Fragment Size?

Background and Objectives: This study was conducted to investigate the effects of fragment size on clinical and radiological outcomes and the development of complications during the surgical treatment of pediatric lateral condyle fractures. Materials and Methods: This retrospective cohort study evaluated data from 47 pediatric patients with lateral condyle fractures, including demographic information, fracture type, range of motion, complications, radiographic assessments, capitellum size, and presence of a lateral bump. Clinical evaluations were performed using the Hardacre functional classification. To objectively investigate the effect of fragment size on prognosis, the total anterior-posterior (AP) and lateral fragment areas, as well as the corresponding AP and lateral capitellum areas (to provide an individualized constant for ratio calculation), were measured. The fractured fragment/capitellum area ratio was then calculated by dividing the fragment area by the respective capitellum area. All statistical analyses were conducted using a two-tailed significance threshold of p < 0.05, and corresponding 95% confidence intervals were calculated where applicable. Results: After a mean follow-up of 66 months (range: 12-142 months), no significant association was identified between the fractured fragment/capitellum area ratio and either the range of motion (p > 0.05) or the presence of a palpable lateral bump (p > 0.05). In contrast, a higher fractured fragment/capitellum area ratio was found to be significantly associated with the presence of radiographic complications (p = 0.01) and a larger final capitellar area (p = 0.02). Conclusions: The fractured fragment/capitellum area ratio, a newly defined parameter for quantifying initial fracture size in pediatric lateral condylar fractures, demonstrated no measurable effects on clinical outcomes, the presence of a lateral bump, or range of motion; however, it was significantly associated with the development of radiological complications and may represent an important predictor of subsequent capitellar hypertrophy. Level of Evidence: This study corresponds to Level III-retrospective cohort study.