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

Abstract

BackgroundDue 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.MethodsThis 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.ResultsThe 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.ConclusionsThis 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.Trial registrationClinical Trial Registry University of Regensburg Z-2017-0930-1. Registered 04. Dec 2017.

The largest secure corridor of the infra-acetabular screw — a 3-D axial perspective analysis

“…In recent years, the treatment trend of acetabular fractures is toward less invasive single ilioinguinal approach, especially in elderly patients [14][15][16][17][18]. Due to the complex characteristic of pelvic anatomy, the safe region of screw placement is far away from the acetabulum, which will reduce the peri-acetabular stability [7]. The common xation methods for acetabular fractures are lag screw xation and plate osteosynthesis [10].…”

“…Culemann et al reported that the entry point for the infra-acetabular screw is 1 cm caudal of the eminelntia iliopectinea and in the middle of the pubic ramus [1]. Baumann et al found that the ideal entry point for the infra-acetabular screw is 10.2 mm caudal and 10.4 mm medial of the eminelntia iliopectinea [7]. Gras et al found that the optimized entry points of infra-acetabular screws are located in the mediocaudal region of the eminelntia iliopectinea [13].…”

“…The treatment of complex acetabular fractures complicated with quadrilateral displacement has been widely studied in recent years [1][2][3][4][5][6]. The goal of acetabular surgery is achieving perfect reduction and rigid xation, allowing early joint movement and avoiding postoperative complications [1,5,7].…”

“…At present, there are many studies on the application of CT data into various software for the xation of periacetabular screws [7,9,[10][11][12][13]. In previous studies, the method of axial perspective can help to nd a larger anterior and posterior column screw path [10,11].…”

Infra-Acetabular Screw Exited Between Ischial Tuberosity and Ischial Spine is more Suitable for Asian Population: A 3D Morphometric Study

“…What's more, they found that congenital hip dysplasia does not affect secure infra-acetabular screw insertion. Baumann et al [10] found the entry point of an ideal infraacetabular was of high constancy, with an average distance of 10.2 mm caudally and 10.4 mm medially to the IPE, which provided a guideline for placement of an infra-acetabular screw via an intra-pelvic approach. The ndings of these scholars could help surgeons safely place an infra-acetabular screw.…”