History 23-year-old man who fell onto his outstretched arm in a rugby tackle. He holds the right arm in slight abduction and external rotation. Right shoulder series.
Right shoulder series: AP and scapular Y views · Click an image to enlarge.
Answer each question aloud before you reveal it. Marks and domains appear only in the revealed answers, as in the exam.
-
Q1 What are your observations?
Reveal answer
A Annotated 3 marks Observation
- AP: humeral head displaced medially and inferiorly, lying below the coracoid and no longer articulating with the glenoid (1)
- Y view: humeral head anterior to the centre of the 'Y' (the glenoid), towards the ribs (1)
- Check the greater tuberosity and glenoid rim for fracture (0.5)
- Look for a posterolateral humeral head impaction (Hill-Sachs) (0.5)
Examiner note 2025 S2 report: many candidates missed Hill-Sachs on x-ray.
-
Q2 What is your preferred diagnosis? Name one other type of this injury and its key radiographic sign.
Reveal answer
2 marks Interpretation
- Preferred: anterior (subcoracoid) glenohumeral dislocation (1)
- Posterior: 'lightbulb' humeral head, rim sign (widened glenohumeral space), trough line (reverse Hill-Sachs); or inferior (luxatio erecta): arm fixed overhead, head below the glenoid (1)
-
Q3 What must happen next, and which imaging?
Reveal answer
2 marks Management/Safety
- Document neurovascular status before and after reduction, especially the axillary nerve (regimental badge sensation, deltoid) (1)
- Prompt reduction with analgesia or sedation, then post-reduction radiographs (AP plus Y or axillary) to confirm reduction and show associated fractures (1)
-
Q4 Which associated injuries should you look for?
Reveal answer
3 marks Applied sciences
- Hill-Sachs lesion: impaction of the posterolateral humeral head against the anterior glenoid rim (Hill & Sachs 1940) (1)
- Bony Bankart: fracture of the anteroinferior glenoid rim (soft-tissue Bankart = labral tear) (1)
- Greater tuberosity fracture; rotator cuff tear (especially over 40); axillary nerve or vascular injury (0.5 each, max 1) (1)
End of the OSCER block (10 marks).
Beyond the exam: teaching extension
Q5–Q9: not part of the 10-mark OSCER block. Untimed, viva-style discussion: mimics and pitfalls, complications, guidelines and report wording.
-
Q5 Which additional views help, and why?
Reveal answer
- Axillary view (or Velpeau if the arm cannot be abducted): the best plain-film view of the head–glenoid relationship; prevents a missed posterior dislocation
- Stryker notch view for Hill-Sachs; West Point view for the anteroinferior glenoid rim (bony Bankart)
- 2025 S2 report: know views beyond the standard AP and lateral
-
Q6 Why are posterior dislocations missed, and how do you avoid it?
Reveal answer
- They are uncommon, and associated with seizures, electrocution and high-energy trauma
- On the AP the head may overlap the glenoid: look for the lightbulb sign, rim sign and trough line
- Always get an orthogonal view (Y or axillary)
-
Q7 When is cross-sectional imaging indicated after a first dislocation?
Reveal answer
- Young, active patients have a high risk of recurrence
- MR arthrography for labral and capsular injury (LO 6.7.2); MRI for the rotator cuff in older patients
- CT to quantify glenoid bone loss and Hill-Sachs engagement for surgical planning
-
Q8 Classify glenohumeral dislocations.
Reveal answer
- Anterior (most common): subcoracoid > subglenoid > subclavicular > intrathoracic
- Posterior; inferior (luxatio erecta); superior (rare)
- Fracture-dislocation; LO Appendix 1 includes 'assessment of stability' in the dislocation entry
-
Q9 Draft the key sentence of your report.
Reveal answer
- 'Anterior (subcoracoid) dislocation of the right glenohumeral joint. No displaced fracture of the greater tuberosity or glenoid rim is seen; assess for a Hill-Sachs lesion on post-reduction films.'
End of questions. Reveal the diagnosis, key takeaways and syllabus mapping below.
Reveal diagnosis, key takeaways & syllabus mapping
Diagnosis Anterior (subcoracoid) glenohumeral dislocation
Key takeaways
- Always get two orthogonal views: an AP alone misses posterior dislocation.
- Name the injury and hunt for Hill-Sachs, bony Bankart and greater tuberosity fractures.
- Check the axillary nerve before and after reduction; get post-reduction films.
- Young patients recur: MR arthrography and CT bone-loss assessment guide surgery.
Syllabus mapping
| OSCER station | Musculoskeletal |
|---|---|
| Learning Outcomes section | §6.7 Musculoskeletal (LO 6.7.2 MR arthrography) |
| Appendix 1 condition | Glenohumeral dislocations (Appendix 1 G, Specific upper limb conditions, p80); Subluxation and dislocation including assessment of stability (G, Traumatic conditions, p78) |
| Category | Category 1 |
| Key Condition | Yes (p78 'Subluxation and dislocation' entry is KC; the p80 'Glenohumeral dislocations' entry is not KC-flagged) |
| Core marks by domain | Observation 3 · Interpretation 2 · Management/Safety 2 · Applied sciences 3 (= 10) |
| Learning objectives | Recognise anterior glenohumeral dislocation on AP and Y views; Search for Hill-Sachs and bony Bankart lesions; Know the additional views and post-reduction care |
Mapped to the RANZCR Clinical Radiology Learning Outcomes v1.3 (January 2024), section 6 and Appendix 1.
Further reading
- Youm T, Takemoto R, Park BK. Acute management of shoulder dislocations. J Am Acad Orthop Surg. 2014;22(12):761–771. PMID 25425611.
- Hill HA, Sachs MD. The grooved defect of the humeral head. Radiology. 1940;35(6):690–700. doi:10.1148/35.6.690.
- RANZCR. Clinical Radiology Learning Outcomes, v1.3 (January 2024), §6 and Appendix 1. Sydney: RANZCR.
- RANZCR. Clinical Radiology Phase 2 OSCER Sample Questions, v1.6 (4 May 2026). Sydney: RANZCR. (Format reference only; no RANZCR images reproduced.)
Always check current Australian/local guidelines.
Image credits
- A by James Heilman, MD, CC BY-SA 4.0, via Wikimedia Commons. Changes: resized and re-encoded (WebP/JPEG). Teaching arrows and labels are a separate overlay added by this site. Adapted image shared under the same licence.
- B by James Heilman, MD, CC BY-SA 4.0, via Wikimedia Commons. Changes: resized and re-encoded (WebP/JPEG). Adapted image shared under the same licence.
Original file titles are listed on the image credits page (they may reveal the diagnosis).