Anatomical relationship between the intertrochanteric line and femoral neck osteotomy level in direct anterior approach total hip arthroplasty: a 3D morphometric and cadaveric validation study

ITL-H serves as a reproducible anatomical landmark for femoral neck osteotomy during DAA-THA. An osteotomy level of approximately 23 mm above the ITL-H represents a safe lower margin to avoid excessive calcar bone resection. Nevertheless, individualized preliminary osteotomy based on preoperative templating remains necessary, with intraoperative adjustment according to patient-specific ITL-H. Video Abstract.