Standard Versus Low-Dose Computed Tomography for Assessment of Acetabular Fracture Reduction

Area of Science:

• Orthopedic Surgery
• Radiology
• Medical Imaging

Background:

• Accurate assessment of acetabular fracture reduction is crucial for optimal patient outcomes.
• Computed tomography (CT) is commonly used for evaluating fracture reduction and implant positioning.
• The impact of varying radiation doses on the diagnostic accuracy of CT in this context is not fully understood.

Purpose of the Study:

• To evaluate how different computed tomography (CT) radiation doses affect surgeon's assessment of acetabular fracture reduction and implant malposition.
• To quantify the accuracy of CT-based assessments compared to known displacements in cadaveric specimens.
• To determine if CT radiation dose influences the ability to detect intra-articular screw placement.

Main Methods:

• Posterior wall acetabular fractures were created in 8 cadaver hips and reduced with controlled step and gap displacements.
• CT scans were performed using standard (120 kV), intermediate (100 kV), and low-dose (80 kV) protocols, with and without metal artifact reduction.
• Reviewers assessed gap, step, and overall displacement, reduction quality, scan quality, and intra-articular screw presence.

Main Results:

• No significant differences in assessing displacement or screw presence were found across varying CT dose protocols.
• Reviewer accuracy in categorizing displacement improved when "anatomic" and "imperfect" categories were combined (52.5%-82.5%).
• Interobserver reliability for all assessed items was poor to moderate; low-dose CT scans were more frequently rated as "inferior".

Conclusions:

• CT radiation dose does not significantly alter the assessment of displacement or intra-articular screw penetration in posterior wall acetabular fractures.
• Surgeon's subjective rating of scan quality is influenced by dose, with lower doses more likely to be rated as inferior.
• These findings suggest that lower radiation dose CT protocols may be viable for evaluating acetabular fracture reduction without compromising diagnostic accuracy.