Diagnosing Rotator Cuff Injury

Clinical Evaluation

The American College of Radiology recommends MRI as the optimal diagnostic imaging modality for rotator cuff injuries, with high sensitivity and specificity for full-thickness tears, while MR arthrography offers superior detection of partial-thickness tears 1, 2
Pain located in the anterior or anterolateral aspect of the shoulder that worsens with overhead activities has a sensitivity of 88% and specificity of 33% 3
Pain during specific phases of throwing motions, such as arm cocking and acceleration phases, is common in athletes 3
Decreased velocity and precision in throwing athletes is a symptom of rotator cuff injury 3
Pain during release, deceleration, and follow-through phases in throwing athletes is also a symptom of rotator cuff injury 4
Decreased range of motion, particularly during abduction with external or internal rotation, is a common finding in patients with rotator cuff injury 3, 4
Focal weakness in the affected shoulder has a prevalence of 75% 3
Neer's test has a sensitivity of 88% and specificity of 33% for diagnosing rotator cuff injury 3
Hawkins' test has a sensitivity of 92% and specificity of 25% for diagnosing rotator cuff injury 3

The American College of Radiology recommends plain radiographs as the initial imaging modality to rule out fractures, dislocations, and other bony abnormalities 1, 2
MRI is the best overall modality for assessing soft-tissue injuries, including rotator cuff pathology, with high sensitivity and specificity for full-thickness tears 1, 2
Ultrasound has high sensitivity and specificity for full-thickness rotator cuff tears, and is equivalent to MRI for evaluating rotator cuff abnormalities, with a sensitivity of 85% and specificity of 90% 1, 2, 3
MR arthrography is preferred for assessing intra-articular pathology and has increased sensitivity for partial-thickness articular surface tears 1, 2
CT arthrography is an alternative when MRI is contraindicated, with similar performance to MR arthrography for full-thickness tears, but significantly poorer performance for partial-thickness tears 1, 2

In youth/adolescent throwers, injuries often result from atraumatic microinstability and weak rotator cuff muscles, and undersurface tears from overuse are more common than primary impingement 3, 4
Scapular dyskinesis contributes to rotator cuff injury, with poor coordination of scapular movements during arm elevation 3, 4
Muscular imbalance, with weakened posterior shoulder musculature and overdeveloped anterior musculature, increases injury risk 3, 4

Noncontrast CT is unable to assess rotator cuff pathology in the acute setting 1, 2
FDG-PET/CT and bone scans are not routinely used for diagnosing rotator cuff tears 1, 2
Ultrasound interpretation is operator-dependent, with variable interobserver agreement for partial-thickness tears 1, 2
Failure to distinguish between primary impingement and secondary impingement may lead to inappropriate treatment 3