Background: Due to the population's longevity and high life expectancy, the frequency of proximal femoral fractures doubles with age. As a result, managing such fractures places a financial and logistical burden on the social and health care systems.

Aim of the work: using Tip Apex Distance (TAD) as a tool for decreasing the incidence of lag screw cut-out in managing proximal femur fractures using cephalo-medullary nailing and dynamic hip screws.

Subject & Methods: This interventional clinical trial included 18 patients 18 with proximal femur fractures managed either by cephalo-medullary nailing or dynamic hip in the Orthopedic department, at Zagazig University Hospitals. Clinical as well as radiological assessments were applied pre- and post-operative.

Results: Gamma nails were used among 10 cases (55.6%) and Dynamic hip screw (DHS) was used among 8 cases (44.4%) of the studied group. Most of the cases (72.2%) didn't have any complications, three cases (16.7%) had cut out and two cases (11.1%) had superficial infections. The mean operative Tip Apex Distance among cases was (19.1± 3.13) ranging from (13.6 to 26.7) mm. Two-thirds of cases (66.6%) had excellent quality reduction, three cases (16.7%) had good quality and three cases (16.7%) had poor quality. TAD increased significantly at 6 months postoperative among patients with poor than good than excellent reduction quality. TAD increased significantly at 6 months postoperative among patients with cut-outs than without cut-outs.

Conclusion: Tip apex distance accuracy plays a crucial function in reducing the incidence of lag screw cut-out in managing proximal femur fractures