Tendon retraction with rotator cuff tear causes a decrease in cross-sectional area of the supraspinatus muscle on...

Area of Science:

• Orthopedic Surgery
• Musculoskeletal Imaging
• Rotator Cuff Pathology

Background:

• Muscle atrophy and fatty degeneration are negative prognostic indicators for rotator cuff repair.
• The Y-shaped view is common for supraspinatus muscle cross-sectional area measurement.
• Tendon retraction and muscle atrophy are critical factors in rotator cuff assessment.

Purpose of the Study:

• To investigate the relationship between rotator cuff muscle cross-sectional area and tendon retraction or tear size.
• To determine the optimal imaging views for assessing muscle atrophy in rotator cuff tears.

Main Methods:

• 76 shoulders with arthroscopically evaluated rotator cuff tears were analyzed.
• Cross-sectional areas of rotator cuff muscles were measured from the Y-shaped view to more medial slices.
• Tendon retraction was measured on oblique coronal images.

Main Results:

• Supraspinatus cross-sectional area and occupation ratio decreased with increasing tear size on the Y-shaped view.
• Significant cross-sectional area decreases were observed in large/massive tears on medial slices.
• A negative correlation between tendon retraction and cross-sectional area was strongest on the Y-shaped view.

Conclusions:

• Tendon retraction influences supraspinatus muscle cross-sectional area measurements.
• Medial slices from the musculotendinous junction are crucial for accurate muscle atrophy evaluation.
• Comprehensive imaging is necessary to avoid misinterpreting muscle atrophy due to tendon retraction.