Rotator cuff tears: association with acromion angulation on MRI

Area of Science:

• Orthopedic Surgery
• Radiology
• Sports Medicine

Background:

• Subacromial impingement syndrome is a common cause of shoulder pain.
• Acromion morphology and coracoacromial ligament (CAL) status are implicated in impingement.
• Understanding these relationships is crucial for diagnosis and treatment.

Purpose of the Study:

• To investigate the correlation between acromion angulation and CAL thickening.
• To assess the relationship between acromion angulation and subacromial space narrowing.
• To determine if acromion angulation is associated with rotator cuff tears.

Main Methods:

• Retrospective analysis of 89 shoulder MRI studies on a 3T scanner.
• Two blinded reviewers measured acromion angle (delta angle) and CAL thickness.
• Subacromial space distance was measured; patients grouped by delta angle (>7.5° vs. <7.5°).

Main Results:

• Steeper acromion angles (Group 2) showed significantly thicker CAL and narrower subacromial space compared to lower angles (Group 1).
• Rotator cuff tears (full or near full thickness) were significantly more prevalent in the steeper acromion group (Group 2).
• No significant interobserver variability was found in measurements.

Conclusions:

• Steep acromion angulation is a significant factor associated with CAL thickening and subacromial space narrowing.
• Increased incidence of rotator cuff tears is linked to steeper acromion angles.
• MRI assessment of acromion morphology may aid in predicting rotator cuff tear risk.