Imaging Recommendations and Surgical Indications for Acute Shoulder Pain

Initial Imaging and Clinical Evaluation

The American College of Radiology recommends that the first imaging study for any acute shoulder pain be plain radiographs with at least three views—anteroposterior (AP) in internal and external rotation plus an axillary or scapula‑Y view—to detect fractures, dislocations, and malalignment. 1
A focused history that includes the mechanism of injury helps differentiate fractures, rotator‑cuff or labral soft‑tissue injuries, and shoulder instability. 2
Young male patients have a higher incidence of traumatic shoulder injuries, so age and activity level should influence the diagnostic suspicion. 2
Physical examination should assess shoulder alignment and joint integrity as part of the initial evaluation. 4

The American College of Radiology specifies three mandatory radiographic views for the shoulder: AP internal rotation, AP external rotation, and either an axillary or scapula‑Y view. The axillary/scapula‑Y view is essential because anterior‑posterior views alone may miss acromioclavicular (AC) and glenohumeral dislocations. 3
When a Hill‑Sachs lesion is suspected, a Stryker notch view should be added to the radiographic series. 4

Order a non‑contrast CT of the shoulder to delineate complex fracture patterns and guide surgical planning; CT provides superior spatial resolution for evaluating fracture planes. 1
If the clinical question is rotator‑cuff integrity in a patient not slated for operative fracture fixation, obtain a non‑contrast MRI instead. 1

Either a non‑contrast CT (high spatial resolution for subtle nondisplaced fractures) or a non‑contrast MRI (detects bone‑marrow edema and concurrent soft‑tissue pathology) may be performed. 1

Proceed with a non‑contrast MRI as the next study; post‑traumatic joint effusion/hemarthrosis supplies natural contrast for soft‑tissue assessment, making MR arthrography unnecessary in the acute setting. 1
Reserve CT without contrast only when MRI cannot adequately evaluate bone loss. 5

Obtain a non‑contrast MRI in the acute/traumatic setting; the effusion generated by trauma adequately distends the joint. MR or CT arthrography is reserved for sub‑acute or chronic cases when the effusion is insufficient. 1

Choose either MRI or ultrasound; both modalities demonstrate 90–91 % sensitivity and 93–95 % specificity for full‑thickness tears.
MRI is preferred in patients with large body habitus, limited range of motion from pain, or when additional intra‑articular pathology (e.g., labral tear) is suspected.
Ultrasound is preferred when proximal humeral hardware would cause MRI artifacts.
Both techniques have reduced and more variable accuracy for partial‑thickness tears. 1

Immediate orthopedic consultation is indicated for unstable or significantly displaced proximal humerus, scapular, or clavicular fractures. 2
Acute surgical stabilization is required for shoulder joint instability that cannot be managed conservatively. 2
Traumatic massive rotator‑cuff tears warrant expedited repair because early intervention improves functional outcomes. 3

Soft‑tissue injuries such as labral tears and non‑massive rotator‑cuff tears may initially be managed non‑operatively with a trial of conservative therapy. 2

Do not omit the axillary or scapula‑Y view; failure to obtain these views frequently leads to missed or misclassified dislocations. 3
Avoid ordering MR arthrography in the acute phase because the post‑traumatic effusion already provides sufficient joint contrast. 1
Do not rely solely on ultrasound for partial‑thickness rotator‑cuff tears, as inter‑observer agreement is poor. 1
In patients with proximal humeral hardware, prefer ultrasound over MRI to prevent artifact‑related image degradation. 1