Internal Rotation Stress Test Reduces Cross-Pinning and Improves Outcomes in Displaced Pediatric Supracondylar Humeral Fractures

Stabilization of the medial column is vital in preventing the loss of fixation and malunion in displaced pediatric supracondylar humeral fractures (SCHFs). The preferred percutaneous pin configuration for medial column fixation remains controversial between medial pinning (cross-pinning) and additional lateral-based pinning. The intraoperative internal rotation stress test (IRST) has been proposed to reliably determine the optimal fixation strategy for each unique fracture. This study evaluated the impact of implementing the IRST on both the choice of pin configuration and institution-wide complications in pediatric patients treated operatively for SCHFs. METHODS: Pediatric patients undergoing percutaneous pinning for SCHFs between 2007 and 2017 at a single center were retrospectively reviewed. The IRST was made a universal institutional practice in 2013. Patients were divided into 2 groups for analysis: (1) patients who underwent treatment before the IRST was implemented in 2013 (the pre-IRST group), and (2) patients who were treated after the IRST was implemented in 2013 (the IRST group). Subgroup analysis was completed for patients in the IRST group who were treated with cross-pinning or 3 lateral-based pins. RESULTS: In this study, 820 patients in the pre-IRST group and 636 patients in the IRST group were included. After the IRST implementation, the rate of loss of fixation fell from 1.2% to 0% (p = 0.003), and the reoperation rate fell from 3.3% to 0.2% (p < 0.001). No cases resulted in a loss of fixation after the adoption of the IRST. The number of patients treated with cross-pinning decreased significantly from 53.2% to 31.6% (p < 0.001) after the IRST implementation, yet cross-pinning continued to be used for more severe fractures. Complication rates within the IRST group were not significantly different (p > 0.05) between cross-pinning and 3 lateral-based pins. CONCLUSIONS: In the largest cohort reported on to date, to our knowledge, institutional implementation of the IRST resulted in a significant reduction in the use of cross-pinning. Although the usage of cross-pinning decreased, cross-pinning was still used frequently in the most severe fractures. The IRST use also resulted in significantly fewer complications such as loss of fixation after institution-wide implementation of the IRST for treating pediatric SCHFs. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.