Review Question - QID 219843

This patient sustained an anterior glenohumeral dislocation (Figure A) with subsequent physical examination concerning for a rotator cuff injury. In a patient over 40 years old, concomitant rotator cuff injury is likely, and the patient underwent MR arthrography. This is the most sensitive and specific test for the identification of rotator cuff pathology (Answer 3).

In older patients, shoulder dysfunction and pseudoparalysis following shoulder dislocations should raise suspicion for an acute traumatic rotator cuff tear. A CT scan may be used to further characterize a proximal humerus fracture; however, plain radiographs are unremarkable for fracture in this case. MRA is the most sensitive in detecting full-thickness and partial-thickness rotator cuff tears, while standard MRI and ultrasonography have comparable sensitivity and specificity.

Gombera et al. reviewed rotator cuff pathology in the setting of anterior shoulder dislocations. They determined that rotator cuff tears often accompany shoulder dislocations, particularly in older patients or athletes, leading to pain, dysfunction, and instability if untreated. Surgical repair generally provides better pain relief and patient satisfaction than nonoperative approaches, especially when both rotator cuff and capsulolabral lesions are addressed. The authors conclude that persistent pain after dislocation should prompt evaluation of the rotator cuff, particularly in patients over 40, or those with nerve injury.

De Jesus et al. conducted a meta-analysis comparing the diagnostic accuracy of MRI, MR arthrography, and ultrasound for rotator cuff tears. They found that MR arthrography is significantly more sensitive and specific than both MRI and ultrasound for diagnosing full- and partial-thickness tears. MRI and ultrasound showed similar sensitivity and specificity, with no significant differences between them. Receiver Operating Characteristic (ROC) curves for MR arthrography, MRI, and ultrasound for all tears show the area under the ROC curve is greatest for MR arthrography (0.935), followed by ultrasound (0.889) and then MRI (0.878). Overall, MR arthrography proved to be the most accurate imaging technique for the identification of rotator cuff pathology.

Figure A: AP right shoulder illustrating an anterior glenohumeral dislocation

Incorrect Answers:
Answers 1 & 5: This patient's physical exam and imaging are more consistent with rotator cuff pathology.
Answers 2 & 4: Radiographs of this patient's injury do not demonstrate any acute osseous abnormalities and MRA is not described as the most sensitive or specific test for identifying humeral head or glenoid fractures.