Beyond 25 millimetres makes the difference: a prospective study on tip apex distance in dynamic hip screw treatment of intertrochanteric fractures

Background: The tip apex distance (TAD) is a key indicator of screw cut-out risk in dynamic hip screw (DHS) treatment for intertrochanteric fractures. This study sought to assess the prognostic significance of TAD in intertrochanteric fractures managed with DHS. Methods: This prospective observational study encompassed 50 patients with intertrochanteric fractures who had DHS fixing treatment. TAD was measured on postoperative radiographs. Patients were followed clinically and radiologically for a minimum of 3 months. The primary outcome was screw cut-out. Results: The mean TAD was 25.5 mm, with a range of 10 to 47 mm. Four screw cut-outs were seen, all in patients with TAD exceeding 35 mm. The mean TAD was 24.18 mm for successfully treated fractures, in contrast to 40.89 mm for those who experienced cut-out. No cut-outs were seen with TAD <25 mm. The inferior-central region of the femoral head was the predominant site for screw placement, occurring in 30% of cases. Conclusions: TAD is a dependable predictor of screw cut-out risk in DHS fixation of intertrochanteric fractures. Maintaining a TAD <25 mm and screw position in the inferior-central zone of the femoral head may help minimize cut-out risk. Surgeons should aim for proper screw placement and consider TAD when treating these fractures.