Abstract
Objective To evaluate and compare the glenoid track method in 3D-reconstructed computed tomography
(3D-CT) scans with magnetic resonance imaging (MRI) and/or arthro-MRI.
Methods Forty-four shoulders with clinical and radiographic diagnosis of traumatic anterior
instability were assessed using 3D-CT, MRI, and/or arthro-MRI scans. Glenoid track
(GT), Hill-Sachs interval (HSI), and glenoid bone loss (GBL) were determined by a
radiologist using 3D-CT images, and classified as on-track/off-track. Three surgeons,
blinded to the radiologist's evaluation, performed the same determinations using MRI/arthro-MRI.
Descriptive analysis, variance analysis, results disagreement analysis, and receiver
operating characteristic (ROC) curves were performed.
Results Results from the 4 examiners were fully consistent in 61.4% of the cases. Magnetic
resonance imaging/arthro-MRI diagnosed off-track injuries with 35 to 65% sensitivity
and on-track injuries, with 91.67 to 95.83% specificity. Accuracy ranged from 68.1
to 79.5%. The greatest data divergence occurred for off-track injuries diagnosed by
MRI/arthro-MRI. The greatest data variability referred to HSI calculation. Higher
HSI and GBL values were associated with greater disagreement among examiners. Hill-Sachs
interval values were lower at MRI/arthro-MRI when compared to 3D-CT. Agreement between
CT and MRI/arthro-MRI for the GT method was only moderate (kappa value, 0.325–0.579).
Conclusion Magnetic resonance imaging/arthro-MRI showed low accuracy and moderate agreement
for the GT method; as such, it should be used with caution by surgeons.
Keywords
glenoid cavity - anterior shoulder instability - shoulder dislocation
