摘要:Purpose: This study examined the effect of lag screw insertion on proximal fragments by separating the right and left sides of intertrochanteric fractures in elderly patients that underwent intramedullary nailing. Materials and Methods: Patients aged ≥65 years that underwent intramedullary nailing after a diagnosis of intertrochanteric fractures during the period February 2012 to May 2016 were included in the study. The subjects were divided into right and left side groups. The effect of the clockwise rotational force generated when a lag screw was inserted on the proximal fragment was evaluated in both groups. Results: In the right and left groups, most proximal fragments were located in the intramedullary canal after surgery (45 cases [75.0%] and 67 cases [73.6%], respectively). Clockwise rotation due to lag screw placement in the right group occurred in two cases (3.3%), which both showed internal rotation, and in four cases (4.4%) in the left group, all of which showed external rotation. Conclusion: After intramedullary nailing of intertrochanteric fractures in elderly patients, proximal fragments were mostly located in the intramedullary cavity. The results obtained confirmed that the clockwise rotational force generated by lag screw insertion did not affect left or right sides.