The Measurement of the Lateral Center-Edge Angle Is Underestimated on Radiographs Compared With 3-Dimensional...

Area of Science:

• Orthopedic surgery
• Radiology
• Hip biomechanics

Background:

• Acetabular coverage assessment is crucial for diagnosing and managing hip pathologies.
• The lateral center-edge angle (LCEA) is a key radiographic measurement for evaluating acetabular coverage.
• Accurate LCEA measurement relies on consistent radiographic landmarks.

Purpose of the Study:

• To compare the accuracy of measuring the lateral center-edge angle (LCEA) using femoral heads (FHs) versus other radiographic landmarks (floor, acetabular teardrops, ischial tuberosities).
• To determine the accuracy of these radiographic measurements against computed tomography (CT) scans.

Main Methods:

• Retrospective analysis of 100 hips from 96 patients with preoperative pelvic radiographs and CT scans.
• LCEA was measured four times per hip on anteroposterior pelvis radiographs using four different anatomic horizons.
• Radiographic LCEA measurements were compared to CT-based measurements at the 12-o'clock position for accuracy.

Main Results:

• Radiographic LCEA measurements (mean 31.1°) were slightly underestimated compared to CT scans (mean 32.2°).
• Using femoral heads (FHs) as the anatomic horizon yielded the lowest mean difference (2.3 ± 2.4) between radiographic and CT measurements.
• A smaller mean difference was observed between FHs and ischial tuberosities (ITs) (1.0 ± 0.8).

Conclusions:

• Femoral heads (FHs) represent a more accurate radiographic landmark for LCEA measurement than acetabular teardrops, ischial tuberosities (ITs), or floor.
• Although statistically significant, the observed differences in LCEA measurements may not be clinically significant.
• Accurate radiographic assessment of acetabular coverage is vital for guiding clinical decisions in hip pathology management.