Is Quantitative Radiographic Measurement of Acetabular Version Reliable in Anteverted and Retroverted Hips?

Area of Science:

• Orthopedic surgery
• Radiology
• Hip biomechanics

Background:

• Accurate acetabular version assessment is vital for hip function and managing hip disorders.
• Existing research shows discrepancies between radiographic and CT measurements, with limited focus on anteverted vs. retroverted hips.

Purpose of the Study:

• To compare the reliability of quantitative radiographic and CT methods for measuring acetabular version angle.
• To investigate differences in measurement reliability between radiography and CT for anteverted and retroverted hips.
• To quantify the variation in acetabular version measurements between radiographic and CT methods across hip types.

Main Methods:

• Retrospective analysis of 122 hips (from 61 patients) with both radiograph and CT scans (Jan 2020 - June 2022).
• Independent measurements by three clinicians, assessing intraobserver and interobserver reliability using Intraclass Correlation Coefficients (ICCs).
• Comparison of measurement agreement between radiography and CT, specifically for anteverted and retroverted hips, using t-tests and Bland-Altman analysis.

Main Results:

• CT measurements showed higher reliability (ICCs 0.91-0.92) than radiographic measurements (ICCs 0.78-0.87).
• Radiographic measurement reliability was moderate for anteverted hips (ICC 0.59) but poor for retroverted hips (ICC -0.41).
• Greater measurement variability was observed with radiographs in retroverted hips (6° ± 4°) compared to anteverted hips (3° ± 3°).

Conclusions:

• While radiographic measurements are acceptable, CT provides superior precision for acetabular version assessment.
• Radiographic methods exhibit a larger margin of error, especially in retroverted hips.
• CT measurement is recommended for precise acetabular version evaluation, particularly in cases of hip retroversion.