Determination of an Intraosseous Safe Corridor for Suprapubic Screw Placement in Total Hip Arthroplasty.

INTRODUCTION: Supplemental screw fixation during total hip arthroplasty (THA) helps improve implant stability and osseointegration. The suprapubic region remains an underdefined region for supplemental screws due to proximity to critical neurovascular structures. This study aimed to define a reproducible, landmark-based intraosseous safe corridor for suprapubic screw placement using three-dimensional (3D) computed tomography (CT) analysis.

METHODS: Preoperative CT scans of 27 patients who underwent primary robotic-assisted THA were retrospectively analyzed. The 3D pelvic reconstructions were oriented to obtain en face sagittal and axial acetabular views. Using consistent intraoperative landmarks, the anterior superior iliac spine (ASIS), acetabular center, and anterior acetabular rim reference lines were established to measure superior-inferior and anterior-posterior intraosseous safe corridor angles using a standardized 25-mm screw length. Median values and interquartile ranges (IQRs) were reported, with subgroup analyses by age, sex, and body mass index (BMI).

RESULTS: In the sagittal plane, the suprapubic intraosseous safe corridor extended a median of 15° (IQR, 12 to 24) superiorly and 9° (IQR, 3 to 16) inferiorly from the reference line. In the axial plane, a reproducible safe entry point was identified 1.5 cm posterior to the anterior acetabular rim, with safe intraosseous corridor boundaries of 4° (IQR, 0 to 12) anteriorly and 31° (IQR, 21 to 36) posteriorly. There were no statistically significant differences detected based on age, sex, or BMI.

CONCLUSIONS: This study defines a consistent, landmark-based intraosseous safe corridor for suprapubic screw placement in THA. These findings provide practical guidance for anterior column fixation during THA and are most applicable in cases with adequate bone stock and non-dysplastic anatomy. Further cadaver and clinical validation of bony pelvic anatomy in revision THA cohorts is warranted to establish a generalizable suprapubic intraosseous safe corridor for more complex cases with aberrant anatomy.