52 children with completely displaced (Type-III) extension supracondylar humerus fracture were randomized to receive either lateral entry pin fixation, or crossed lateral and medial entry pin fixation. This study aimed to compare loss to reduction and incidence of iatrogenic ulnar nerve injury. Results demonstrated that both procedures were effective in treating type-III extension supracondylar humerus fractures at the 3-month follow-up. Both groups did not have a major loss of reduction, and there was no significant difference between rates of mild loss of reduction. Furthermore, both groups showed no cases of iatrogenic ulnar nerve injury.