In which condition is the Hamilton Ruler test sign positive?

Anterior dislocation of shoulder

Posterior dislocation of shoulder

Acromioclavicular joint dislocation

Hill-Sachs lesion is seen in?

Anterior dislocation of shoulder joint

Posterior dislocation of shoulder joint

A 30-year-old male presents with pain and limited movement in his shoulder following a fall. X-ray reveals an anterior dislocation of the glenohumeral joint. Which of the following structures is most likely to be damaged in this injury?

Anterior inferior glenohumeral ligament

Which activity will be difficult to perform for a patient with an anterior cruciate deficient knee joint?

Getting up from a sitting position

Shoulder Instability for FMGE: High-Yield Orthopaedics Lessons

Anatomy & Biomechanics - Anatomy's Tightrope Act

Glenohumeral Joint (GHJ): Inherently unstable; relies on static & dynamic stabilizers.
Static Stabilizers:
- Glenoid: Shallow; retroversion 2-7°.
- Labrum: Fibrocartilage, deepens glenoid.
  
  ⭐ Labrum increases glenoid depth by ~50%.
- Ligaments:
  - SGHL: Resists inferior translation (adducted).
  - MGHL: Limits ER at 0-45° abd. (📌 MGHL May Go Hiding - often variable).
  - IGHLC: Main anterior stabilizer in ABER position (90° abd. + ER).
- Negative intra-articular pressure.
Dynamic Stabilizers:
- Rotator Cuff (SITS): Compresses humeral head.
- Long Head of Biceps (LHB): Depresses head.
- Scapulothoracic rhythm.

Shoulder Joint Ligaments and Tendons

Classification & Lesions - Decoding the Wobble

Etiology: Traumatic, Atraumatic, Microtraumatic (repetitive).
Direction: Anterior, Posterior, Inferior (Luxatio erecta), Multidirectional (MDI).
Severity: Dislocation (complete) vs. Subluxation (partial).

⭐ Anterior instability is the most common type (approx. 95%).

Feature	TUBS	AMBRI
Etiology	Traumatic	Atraumatic
Direction	Unidirectional (usually Anterior)	Multidirectional
Pathology	Bankart lesion	Often bilateral, capsular laxity
Treatment	Surgery (often required)	Rehabilitation (primary), Inferior capsular shift (if surgery)
📌 Mnemonic	Torn Loose, Bankart, Surgery	Atraumatic, Multidirectional, Bilateral, Rehabilitation, Inferior capsular shift

- **Bankart Lesion**: Anteroinferior labrum & IGHL detachment.
    + Bony Bankart: Involves glenoid rim fracture.
    ![Bankart Lesion: Anterior Inferior Labral Tear](https://ylbwdadhbcjolwylidja.supabase.co/storage/v1/object/public/notes/L1/Orthopaedics_Sports_Medicine_Shoulder_Instability/65208883-ee75-4d5f-a02a-ad846fcd87f8.jpg)
- **Hill-Sachs Lesion**: Posterolateral humeral head impaction fracture.
    ![Bankart Lesion of the Shoulder](https://ylbwdadhbcjolwylidja.supabase.co/storage/v1/object/public/notes/L1/Orthopaedics_Sports_Medicine_Shoulder_Instability/c556102e-ee01-497a-bdd2-d17524683119.jpg)
- ALPSA: Anterior Labrum Periosteal Sleeve Avulsion.
- HAGL: Humeral Avulsion of Glenohumeral Ligament.
- SLAP: Superior Labrum Anterior-Posterior tear.

Diagnosis & Evaluation - Clinical Detective Work

History: Mechanism (FOOSH, direct blow, overuse), prior dislocations, pain, clicking, "dead arm" sensation. Differentiate TUBS vs. AMBRI.
Examination: Observe (asymmetry, atrophy), palpate key structures, assess active/passive ROM. Neurovascular status crucial.

Special Tests:

Test Category	Key Tests
Anterior Instability	Apprehension, Relocation, Surprise
Posterior Instability	Posterior Drawer, Jerk Test
Inferior Instability	Sulcus Sign (Grades +1/+2/+3)
Labral/SLAP	O'Brien's, Crank Test

Imaging:
- X-rays: AP, Grashey, Axillary lateral. Consider West Point (bony Bankart), Stryker Notch (Hill-Sachs).
⭐ The West Point axillary view is best for imaging a bony Bankart lesion.
- MRI/MR Arthrogram: Gold standard for labral tears, capsular injury, RTC.

Management Principles - Fixing the Flux

Goal: Restore stability & function; prevent recurrence & arthropathy.
Conservative Management (Often first-line):
- Immobilization (sling for comfort, brief duration).
- Physiotherapy: Key for AMBRI. Focus on rotator cuff, deltoid, and scapular stabilizer strengthening.
- Activity modification.
Surgical Management (Indications vary by instability type):
- TUBS: Often requires surgery after first dislocation in high-demand individuals or for recurrence.
  - Arthroscopic Bankart Repair: For labral tears without significant bone loss.
  - Latarjet Procedure: For significant glenoid bone loss >20-25% or failed soft-tissue repair.
- AMBRI: Surgery (e.g., capsular shift/plication) if extensive physiotherapy fails.
- 📌 Mnemonic (Instability Types & Treatment Bias):
  - TUBS: Traumatic, Unidirectional, Bankart lesion, Surgery often needed.
  - AMBRI: Atraumatic, Multidirectional, Bilateral, Rehabilitation (primary), Inferior capsular shift (if surgery).

Bankart vs. Latarjet: Patient-reported outcomes over 2 years

⭐ Latarjet procedure is indicated for recurrent anterior instability with significant glenoid bone loss (typically >20-25%) or failed previous soft tissue repairs.

High‑Yield Points - ⚡ Biggest Takeaways

Anterior instability (95%) is most common, from abduction & external rotation.

Bankart lesion (anteroinferior labral tear) is pathognomonic for traumatic anterior instability.

Hill-Sachs lesion (humeral head impaction) often co-exists with Bankart.

Key acronyms: TUBS (Traumatic, Unidirectional, Bankart, Surgery) & AMBRI (Atraumatic, Multidirectional, Bilateral, Rehabilitation).

Tests: Apprehension, Relocation (anterior); Sulcus sign (inferior/MDI).

High recurrence of traumatic dislocations in young, active patients.

Posterior instability often follows seizures/electric shock.

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Shoulder Instability