[Radiologic and morphologic evaluation of the lateral sacral mass]

Area of Science:

• Orthopedic surgery
• Anatomy
• Radiology

Background:

• Iliosacral screw fixation is a common procedure for stabilizing sacral fractures.
• Accurate anatomical knowledge of the lateral sacral mass (LSM) is crucial for safe screw placement.
• Previous studies have provided limited data on the morphometric analysis of the LSM for surgical planning.

Purpose of the Study:

• To perform morphologic measurements of the lateral sacral mass (LSM) and adjacent bone structures.
• To evaluate the appropriateness of the LSM area for iliosacral screw applications using CT scans.
• To provide anatomical data to enhance the safety of iliosacral screw fixation.

Main Methods:

• Morphologic measurements of the LSM were taken on 30 dried human sacrum specimens.
• Computed tomography (CT) scans were obtained for S1 and S2 pedicle-bodies and intervertebral foramina.
• Radiologic measurements were performed to assess the relationship between the LSM, neural canal, and intervertebral foramina.

Main Results:

• Average LSM widths varied between posterior (18.4-24.5 mm) and anterior (22.6-29.1 mm) aspects across S1 and S2 levels.
• Average oblique LSM heights ranged from 27.6-39 mm.
• CT measurements showed average pedicle+sacral ala widths of 36.3-37.6 mm at S1 and pedicle+LSM widths of 26.4-27.8 mm at S2.

Conclusions:

• Iliosacral screw fixation can be performed more safely at the S1 pedicle-body level, lateral to the sacral neural canal and intervertebral foramina.
• Preoperative CT-based measurements of the LSM are recommended to minimize the risk of neural tissue injury.
• This study provides valuable anatomical data for optimizing surgical techniques in sacral fracture fixation.