Correlations between Capsular Changes and ROM Restriction in Frozen Shoulder Evaluated by Plain MRI and MR...

Area of Science:

• Orthopedic imaging
• Shoulder biomechanics
• Diagnostic radiology

Background:

• Range of Motion (ROM) evaluation is crucial for diagnosing shoulder disorders.
• Frozen shoulder often involves significant ROM restrictions.
• Capsular changes are implicated in frozen shoulder pathophysiology.

Purpose of the Study:

• To investigate correlations between capsular changes and ROM restrictions in frozen shoulder.
• To compare findings from plain Magnetic Resonance Imaging (MRI) and Magnetic Resonance Arthrography (MRA).
• To assess the utility of MRA in quantifying capsular changes related to ROM limitations.

Main Methods:

• Evaluated 24 frozen shoulder patients (mean age 60.5) who underwent both MRI and MRA.
• Assessed ROM, coracohumeral ligament (CHL) thickness, axillary recess area, and capsular thickness.
• Utilized both MRI and MRA for comparative analysis of capsular structures.

Main Results:

• MRA showed positive correlations between axillary area and multiple ROM measures (forward flexion, lateral elevation, external rotation, abduction with external rotation, hand behind back).
• Negative correlations were observed between glenoid-side joint capsule thickness and external rotation/hand behind back on both MRI and MRA.
• Axillary area and glenoid capsule thickness emerged as key imaging indicators.

Conclusions:

• The axillary area, assessed via MRA, significantly correlates with ROM restrictions in frozen shoulder.
• Glenoid-side joint capsule thickness is a critical factor contributing to ROM limitations.
• MRA provides valuable insights into capsular changes affecting shoulder function in frozen shoulder.