One hundred children with supracondylar femoral fractures (SFF) were randomized to receive either distal femur 90° locking plate fixation (n=50) or Kirschner wire (K wire) internal fixation (n=50). The primary outcome of interest was fracture union rate. Secondary outcomes included knee joint function (Harris-Hip-Score, Flynn score), intracavitary knee pressure, weight-bearing recovery time, and postoperative complications. Outcomes were assessed at 12, 16, 20, 24, and 28 weeks. Overall, the results of the study revealed that the distal femur 90° locking plate fixation had a significantly higher fracture union rate at earlier time points (12–24 weeks) compared to K wire fixation (p<0.05), with no significant difference at 28 weeks. Additionally, the study group showed better knee joint function scores, lower intracavitary knee pressure at 8 and 16 weeks, and fewer postoperative complications (p<0.05). These findings suggest that distal femur 90° locking plate fixation provides a more stable and effective fixation method for pediatric SFF, particularly benefiting children with diabetes.