Shoulder
| Injury | Imaging |
|---|---|
| Anterior dislocation (~95%; subcoracoid commonest) | humeral head anterior–inferior to the glenoid, under the coracoid; Hill–Sachs lesion (impaction defect of the posterolateral humeral head), bony/soft Bankart lesion (anteroinferior glenoid rim/labrum); greater tuberosity fracture; axillary nerve; recurrence high in the young; MR arthrography for labral injury |
| Posterior dislocation (2–4%; often missed) | seizures, electrocution, extreme trauma ("3 Es"; triple E syndrome: bilateral posterior locked fracture‑dislocation); AP: light‑bulb sign (internal rotation), rim sign (widened glenohumeral space > 6 mm), trough line sign (reverse Hill–Sachs: anteromedial head impaction), loss of the half‑moon overlap; axillary or scapular Y view confirms |
| Inferior (luxatio erecta) | arm fixed abducted overhead; head below the glenoid |
| Proximal humerus fracture | elderly osteoporotic; surgical neck commonest site; Neer classification (four parts: head, greater tuberosity, lesser tuberosity, shaft; a part is displaced if > 1 cm or angulated > 45°); AVN risk with 4‑part/anatomical neck |
| Clavicle | middle third (~80%); lateral third (coracoclavicular ligament integrity) |
| AC joint | Rockwood types; normally inferior margins of acromion and clavicle aligned; coracoclavicular distance < 13 mm |
| Scapula | high‑energy; CT; associated chest injury |