4. Radiographic Assessment

All radiographic measurements (e.g., bone union time, nonunion, sliding, angulation of lag screw, and screw tip migration) were evaluated using AP and lateral radiographs with PACS (Picture Archiving and Communication Systems). Bone union was judged as callus appearance across the fracture line on AP and lateral radiographs. Radiologic failure was defined as i) screw sliding at more than 15 mm, ii) varus collapse of the proximal fragment, iii) lag screw cut-out from the femoral head, iv) varus angulation at more than 5°, or v) screw-tip migration greater than 7 mm¹⁴⁾.