A guideline for placement of an infra-acetabular screw based on anatomic landmarks via an intra-pelvic approach

• Published in: Journal of orthopaedic surgery and research Vol. 13; no. 1; p. 77
• Main Authors: Baumann, Florian, Schmitz, Paul, Mahr, Daniel, Kerschbaum, Maximilian, Gänsslen, Axel, Nerlich, Michael, Worlicek, Michael
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 10.04.2018; BioMed Central; BMC
• Subjects: Acetabulum - anatomy & histology; Acetabulum - diagnostic imaging; Acetabulum - injuries; Acetabulum - surgery; Acetabulum fracture; Analysis; Anatomic Landmarks; Bone Screws; Bones; Entry point; Female; Fracture Fixation, Internal - instrumentation; Fracture Fixation, Internal - methods; Fractures, Bone - diagnostic imaging; Fractures, Bone - surgery; Health aspects; Humans; Imaging, Three-Dimensional - methods; Infra-acetabular screw; Intra-pelvic approach; Male; Medical equipment; Morphometrics (Biology); Practice guidelines (Medicine); Radiography; Screw fixation; Tomography, X-Ray Computed - methods; Screw fixation; Infra-acetabular screw; Anatomic landmarks; Intra-pelvic approach; Entry point; Acetabulum fracture
• ISSN: 1749-799X; 1749-799X
• DOI: 10.1186/s13018-018-0786-1

Due to demographic changes, more and more fracture patterns involving anterior acetabular structures occur. The infra-acetabular screw is seen a useful tool to increase stability in fixation of the acetabular cup. However, the exact position of this screw in relation to anatomic landmarks which are intra-operatively palpable via an intra-pelvic approach has not yet been determined. This biomorphometric experimental study references the ideal screw position of an infra-acetabular screw to anatomic landmarks palpable via an intra-pelvic approach. Therefore, we created a computer tomography-based 3D-model of 40 patients (20 women, 20 men) who received a computer tomography (CT) scan of the pelvis for any other reason than an acetabular fracture. The entry point of an ideal infra-acetabular was of high constancy. At mean, this point was 10.2 mm caudal and 10.4 mm medial of the ilio-pubic/ilio-pectineal eminence. This reference is independent of age, gender, or physical dimensions. However, we found gender-dependent differences for the angulation and the length of the screw. This study provides a comprehensive guideline to determine the ideal entry point for an infra-acetabular screw via an intra-pelvic approach. The entry point is located 10.2 mm caudal and 10.4 mm medial of the ilio-pubic/ilio-pectineal eminence. Clinical Trial Registry University of Regensburg Z-2017-0930-1 . Registered 04. Dec 2017.