The Limited Significance of the Internal Rotation Stress Test in Pediatric Gartland Type III Supracondylar Humerus Fractures

<b>Background:</b> Gartland type III pediatric supracondylar humerus fractures can be unstable and prone to loss of reduction. The Internal Rotational Stress Test (IRST) aims to assess and address rotational instability during surgery. <b>Method:</b> This retrospective study analyzed treatments for Gartland type III pediatric supracondylar humerus fractures at our institution from January 2020 to December 2022. Only patients who underwent IRST were included. IRST was performed after inserting either two or three lateral pins. Patients were divided into Group 1 (IRST +) or 2 (IRST -) based on IRST results. Radiographic and clinical outcomes were compared between the two groups. <b>Result:</b> A total of 46 patients were included in the study. The mean age at the time of diagnosis was 5.7 years (range, 4 to 11 years), and the mean duration of follow-up was 2.8 years (range, 1.0 to 4.8 years). Group 1 consisted of 24 patients, and Group 2 comprised 22 patients. We did not find any differences in radiographic parameters and clinical scores between the two groups. Additionally, in both groups, there were no instances of major loss of reduction, defined as greater than 12 degrees or 12%. In five patients, we identified two types of fracture patterns that were stable with only two lateral pins. <b>Conclusions:</b> In patients with Gartland type III supracondylar humerus fractures, if reduction is adequately achieved and sufficient fixation force is maintained, the IRST results do not significantly impact radiologic and clinical outcomes. The pattern of the fracture can influence instability, necessitating further research on this matter.