🩺 Traumatic Elbow Injuries — A Complete RCEM-Aligned Guide for FRCEM Candidates

09/10/2025.

🔍 Introduction

Traumatic elbow injuries account for 2–3 % of all Emergency Department presentations, and subtle radiographic findings are easily missed.
 Understanding key lines, injury patterns, and management priorities is essential for safe practice — and frequently tested in the Final FRCEM SBA exam.

This guide summarises the RCEMLearning reference on Traumatic Elbow Injuries with concise explanations, imaging pearls, and take-home messages — integrated with high-yield exam preparation from FRCEM StudyZone
.🦴 1. Elbow Anatomy — The Foundation for Every Diagnosis

The elbow is a hinge joint comprising three articulations:

• Humeroulnar joint — hinge stability
• Humeroradial joint — pronation/supination
• Proximal radioulnar joint — rotational motion

Key stabilisers:

• Medial (ulnar) and lateral collateral ligaments resist valgus and varus forces.
• Annular ligament anchors the radial head.
• The ulnar nerve runs posterior to the medial epicondyle; the brachial artery and median nerve traverse the cubital fossa anteriorly.

🧠 StudyZone Tip: Knowing this anatomy aids rapid identification of nerve involvement and ligamentous instability in trauma questions — revisit our Musculoskeletal SBA Pack
for detailed anatomy-based questions.

👨‍⚕️ 2. Structured Clinical Assessment

A systematic approach prevents missed diagnoses:

History

Mechanism (FOOSH, direct blow, twisting), onset, pain radiation, paraesthesia, and previous injury. In children, exclude non-accidental injury.

Examination – Look, Feel, Move, Special Tests

Look:

• Deformity, swelling, bruising.
• Check the epicondyle–olecranon relationship:
  • In flexion → triangle,
  • In extension → straight line.
     Disruption suggests dislocation.

Feel:

• Palpate epicondyles, olecranon, radial head.
• Tenderness over radial head or olecranon → possible fracture.

Move:

• Active/passive flexion (0–140°), pronation/supination (~150° arc).
• Pain with supination → radial head fracture.

Special Tests:

• Valgus/varus stress → collateral ligament integrity.
• Resisted wrist extension → lateral epicondylitis.
• Resisted wrist flexion → medial epicondylitis (often with ulnar nerve irritation).

🔗 Practise similar structured assessment SBAs inside our Trauma & Musculoskeletal Section
.

📸 3. Radiographic Interpretation — The “Important Lines” Every Candidate Must Know

Understanding normal alignment is the cornerstone of elbow imaging.

Anterior Humeral Line

• Drawn along the anterior humeral cortex on the lateral X-ray.
• Should intersect the middle third of the capitellum.
• If it passes anteriorly, suspect posterior displacement — typically in supracondylar fractures.

Radiocapitellar Line

• Line through the centre of the radius must always intersect the capitellum in all views.
• Deviation → radial head dislocation or Monteggia injury.

Fat Pad (Sail Sign)

• Posterior fat pad visible? → Always abnormal.
• Indicates intra-articular effusion, usually due to occult fracture.

Paediatric Ossification Centres (CRITOE)

• Capitellum – 1 yr
• Radial head – 3 yr
• Internal (medial) epicondyle – 5 yr
• Trochlea – 7 yr
• Olecranon – 9 yr
• External (lateral) epicondyle – 11 yr

Understanding these prevents confusion between growth centres and fractures.

🧠 StudyZone Take-Home Message:
Always draw the lines and look for the fat pad sign. Missed alignment = missed diagnosis.

Explore radiology-focused SBAs in our Emergency Imaging Category
.

💥 4. Common Traumatic Patterns & Management

Supracondylar Fracture (Children)

• Mechanism: Fall on outstretched hand (extension-type).
• Anterior humeral line anterior to capitellum.
• Management: Immobilisation, neurovascular checks, urgent orthopaedic referral.
• Complication: Brachial artery injury → compartment syndrome.

Radial Head Fracture

• Pain on pronation/supination; lateral tenderness.
• Often subtle on X-ray — fat pad may be the only clue.
• Management: Early mobilisation (<3 weeks).
• Check for: Essex-Lopresti injury (wrist DRUJ).

Elbow Dislocation

• Most are posterior/posterolateral.
• Look for alignment loss of olecranon–epicondyle triangle.
• Immediate reduction + post-reduction imaging.

Olecranon Fracture

• Inability to extend elbow = loss of extensor mechanism.
• Displacement >5 mm → operative repair.

Monteggia Injury

• Ulna fracture + radial head dislocation.
• Always check radiocapitellar line when ulna is fractured.

🩺 High-yield cross-reference: Our Trauma SBA Pack
includes consultant-written MCQs covering Monteggia, Essex-Lopresti, and supracondylar fractures.

⚠️ 5. Common Pitfalls in the ED

PitfallConsequenceFRCEM TipIgnoring posterior fat pad | Missed occult fracture | Treat as fracture until proven otherwise
Failure to test neurovascular status | Missed compartment syndrome | Always check radial/ulnar pulses, median/ulnar nerve
Confusing ossification centres with fractures | Over-diagnosis | Recall CRITOE sequence
Immobilising >3 weeks | Stiffness, poor outcome | Encourage early mobilisation
Not imaging wrist/forearm | Missed associated injuries | Always image joints above and below

🧩 6. Example FRCEM-Style Question

A 9-year-old boy presents after a fall on his outstretched hand.
Lateral X-ray shows the anterior humeral line passing anterior to the middle third of the capitellum and a posterior fat pad.

Which injury best fits these findings?

A. Lateral condyle fracture
 B. Posterior elbow dislocation
 C. Supracondylar fracture (extension type) ✅
D. Monteggia fracture
E. Capitellar fracture

💡 Answer Explanation:
Posterior displacement of the distal fragment (anterior humeral line abnormal) = extension-type supracondylar fracture.
Fat pad = intra-articular effusion confirming fracture even if subtle.

🔗 More imaging-based questions are available in our Mock Exam Section
.

🧠 7. StudyZone Take-Home Messages

✅ Always draw the anterior humeral and radiocapitellar lines.
✅ A posterior fat pad = fracture until proven otherwise.
✅ Know the CRITOE ossification sequence to avoid misreading children’s X-rays.
✅ Immobilise briefly; mobilise early.
✅ Always assess neurovascular status and associated injuries.
✅ Revise trauma patterns regularly using RCEM-aligned SBAs.

Explore all relevant modules in our Trauma & Musculoskeletal Category
.

🏁 Conclusion

Traumatic elbow injuries demand precision in assessment, imaging, and decision-making.
 For the FRCEM SBA, understanding “important lines,” common fracture patterns, and early complications is indispensable.

At FRCEM StudyZone, our mission is to help you:

Prepare smarter, think like an examiner, and master RCEM-aligned emergency scenarios.

📘 Continue Learning:
🔗 Explore Categories

🔗 Join Mock Exam Series

🧑‍⚕️ Written and reviewed by NHS Emergency Medicine Consultants
© 2025 FRCEM StudyZone — Where Preparation Meets Precision.