Superior glenoid inclination and rotator cuff tears

Area of Science:

• Orthopedics
• Radiology
• Shoulder Surgery

Background:

• Assessing glenoid inclination is crucial for shoulder pathologies.
• Magnetic resonance imaging (MRI) is a common imaging modality, but its accuracy for glenoid inclination measurement needs validation.
• Computed tomography (CT) is considered the gold standard for bone measurements.

Purpose of the Study:

• To evaluate the accuracy and reliability of glenoid inclination measurements using MRI.
• To compare glenoid inclination between patients with rotator cuff tears and healthy controls.

Main Methods:

• A retrospective study measured glenoid inclination on T1 coronal MRI, corrected to the plane of the scapula.
• Accuracy was assessed by comparing MRI measurements to CT scans.
• Inter-rater reliability was determined for MRI measurements.
• Glenoid inclination was compared between a rotator cuff tear group (n=192) and a control group (n=107).

Main Results:

• MRI measurements of glenoid inclination showed high accuracy compared to CT (intraclass correlation coefficient [ICC] = 0.877).
• MRI measurements demonstrated excellent inter-rater reliability (ICC = 0.911).
• Superior glenoid inclination was significantly higher in the rotator cuff tear group (2° greater, P < .001).

Conclusions:

• Glenoid inclination can be accurately and reliably measured using MRI.
• While statistically significant, the observed increase in superior glenoid inclination in rotator cuff tear patients is likely below the threshold for clinical significance.