How can you differentiate a shoulder dislocation from a humeral head fracture on exam and imaging?

• A. Dislocation shows diffuse swelling without deformity
• B. Fracture shows obvious deformity with no swelling
• C. Imaging is never useful in shoulder injuries
• D. Dislocation typically presents with obvious deformity and severe limitation; fracture presents with focal pain and swelling and may require imaging

Answer: (D)

Differentiating these injuries hinges on how they look and what imaging shows. A shoulder dislocation usually creates an obvious deformity of the shoulder contour—the head of the humerus is out of place relative to the glenoid—and the patient has severe pain with a marked limitation in lifting or rotating the arm. In contrast, a proximal humeral head fracture tends to produce focal tenderness over the proximal humerus, swelling and bruising, with less dramatic deformity and a more localized pain pattern. Imaging helps confirm the diagnosis and guide treatment: radiographs with multiple views (including axillary or scapular Y views if a dislocation is suspected) show whether the humeral head is displaced from the glenoid or if a fracture line is present, and CT can further define complex fractures. Therefore, the description that dislocation presents with obvious deformity and severe limitation, while fracture presents with focal pain and swelling and may require imaging, best fits the typical exam and imaging distinction.