MR evaluation of subscapularis tears.

Area of Science:

• Orthopedic Surgery
• Radiology
• Musculoskeletal Imaging

Background:

• Rotator cuff tears are common injuries.
• The subscapularis tendon is a key component of the rotator cuff.
• Understanding the imaging characteristics and associated injuries of subscapularis tears is crucial for diagnosis and treatment.

Purpose of the Study:

• To characterize the magnetic resonance (MR) imaging appearance of subscapularis tendon tears.
• To evaluate the effectiveness of different imaging planes (axial, coronal, sagittal) in visualizing these tears.
• To determine the association of subscapularis tears with other rotator cuff tears and biceps tendon dislocations.

Main Methods:

• Retrospective review of 1.5 T MR studies over an 8-year period.
• Assessment for subscapularis tears and associated rotator cuff tears (supraspinatus, infraspinatus, teres minor).
• Evaluation for biceps tendon dislocation and the "naked humerus sign"; correlation with surgical reports.

Main Results:

• Subscapularis tears were identified in 2% (45/2167) of rotator cuff tears, with 27% partial and 73% complete.
• Tears were most conspicuous on sagittal oblique MR images.
• Associated injuries included supraspinatus tears (79%), infraspinatus tears (56%), biceps dislocations (49%), and the naked humerus sign (69%).

Conclusions:

• Subscapularis tendon tears represent a small but significant subset of rotator cuff injuries.
• Sagittal oblique MRI is optimal for visualizing subscapularis tears.
• These tears frequently occur in conjunction with other rotator cuff pathology and biceps tendon abnormalities.