EDAITUTOR
ED Reference · Paeds X-ray v0.1 · illustrated Educational use only

Reading the
Paediatric Elbow

A systematic read for the ED — fat pads · the lines · CRITOE — and the can't-miss fractures hiding in a growing skeleton.

LinesFat padsCRITOE

🔴 The paediatric elbow is a trap

Ossification centres mimic fractures and fractures hide. A posterior fat pad = effusion = occult fracture until proven otherwise. Always check the anterior humeral & radiocapitellar lines, know the CRITOE order, and correlate with the point of maximal tenderness. If the exam says fracture, treat it as one and get senior / orthopaedic review.

Approach
  • Adequate views — AP + a true lateral
  • Soft tissues & fat pads
  • Anterior humeral & radiocapitellar lines
  • CRITOE ossification centres
  • Cortex & each bone in turn
⚪ tipA true lateral shows a tear-drop and the capitellum as the leading rounded ossification centre.
🟢 RCH · Radiopaedia
Fat pads
  • Anterior pad: small lucency is normal; raised = sail sign
  • Posterior pad: never normally seen — if visible it is always abnormal
  • Either raised pad = joint effusion
  • Effusion = occult fracture until proven otherwise
🔴 ruleA posterior fat pad with no visible fracture → treat as an occult fracture (often supracondylar / radial neck), splint & review.
🟢 LITFL · Radiopaedia
The lines
  • Anterior humeral line → should cross the middle third of the capitellum
  • If it passes anteriorly → supracondylar fracture (capitellum pushed back)
  • Radiocapitellar line → through the capitellum in every view
  • If it misses → radial head dislocation (think Monteggia)
⚠ both viewsThe radiocapitellar line must hold on AP and lateral.
🟢 Radiopaedia · Orthobullets
CRITOE
C1
R3
I5
T7
O9
E11
  • Capitellum · Radial head · Internal (medial) epicondyle
  • Trochlea · Olecranon · External (lateral) epicondyle
  • Appear in order, ~ages 1·3·5·7·9·11 (girls earlier)
🔴 the trapIf the trochlea is present but the medial epicondyle isn't, suspect an avulsed medial epicondyle trapped in the joint.
🟢 Don't Forget the Bubbles · RCH
How to read it well — a safe routine

Get a true lateral

A poorly positioned elbow hides fat pads and fakes line abnormalities — insist on an adequate AP + true lateral.

🟢 RCH

CRITOE

Know CRITOE first

Confirm the ossification order before calling any "fragment" a fracture — and use it to catch the medial epicondyle trap.

🟢 DFTB

Never ignore a pad

A posterior fat pad is an effusion until proven otherwise — treat the child as having an occult fracture.

🟢 LITFL

Correlate clinically

Match the film to the point of maximal tenderness and neurovascular exam — the child, not just the X-ray.

🟢 Orthobullets

Key signs on the film — tap any image to enlarge
Anterior humeral line and radiocapitellar line on a paediatric lateral elbow X-ray

1The lines

Anterior humeral line through the middle third of the capitellum; radiocapitellar line points into the capitellum.

Tap to enlarge
Image: Radiology Expert (educational use)
CRITOE ossification centres labelled on AP and lateral paediatric elbow X-rays

2CRITOE centres

The six ossification centres — C·R·I·T·O·E — appearing in their predictable order on the growing elbow.

Tap to enlarge
Image: educational reference
Elevated anterior and posterior fat pads on a paediatric lateral elbow X-ray

3Fat pads

Raised anterior (sail) and visible posterior fat pads (arrows) — a joint effusion signalling occult fracture.

Tap to enlarge
Image: RiT Radiology (educational use)
⚪ use them togetherThese three checks catch the great majority of paediatric elbow injuries — disrupted lines, an out-of-order CRITOE, or a tell-tale fat pad. Images are external educational references, not produced by ED AI Tutor.
Read it step-by-step — a repeatable routine
1

Adequate views

  • AP + a true lateral
  • Repeat if poorly positioned
2

Fat pads

  • Raised anterior = sail · any posterior = abnormal
effusion = occult #
3

Anterior humeral line

  • Down the anterior humeral cortex
  • Crosses the middle third of capitellum
4

Radiocapitellar line

  • Radial shaft axis → through capitellum
  • Holds on AP and lateral
5

CRITOE

  • Confirm centres appear in order
  • Watch the medial epicondyle trap
order, not age
6

Supracondylar

  • Most common — check the line first
  • Look at the posterior cortex
7

Each bone

  • Radial head/neck · olecranon · condyles
  • Trace each cortex for a step
8

Synthesise

  • Pull lines, pads & CRITOE together
  • Match to the clinical exam
treat the child
Common paediatric elbow fractures
most common · extension type

Supracondylar

Anterior humeral line off the capitellum (Gartland I–III). Check NV status — AIN / brachial artery.

neurovascular check
2nd most common · SH IV

Lateral condyle

Risk of non-union & growth disturbance; often needs ORIF. Easily under-called.

refer orthopaedics
avulsion · valgus

Medial epicondyle

May be trapped in the joint — use CRITOE order to spot it. Associated with dislocation.

CRITOE trap
FOOSH

Radial neck

Check the radiocapitellar line and angulation; common cause of an isolated effusion.

angle matters
ulna # + radial head dislocation

Monteggia

Don't miss the dislocation — the radiocapitellar line is the giveaway.

check the line
toddler · pulled arm

Pulled elbow

Radial head subluxation; X-ray usually normal; reduce clinically (supination-flexion / hyperpronation).

clinical diagnosis
⚪ classify & referUse the appropriate classification (e.g. Gartland for supracondylar) and discuss displaced or intra-articular fractures with orthopaedics. Document distal neurovascular status before and after any manipulation.
Don't miss
  • Occult #posterior fat pad with no visible fracture
  • Supracondylarsubtle — anterior humeral line off the capitellum
  • Medial epi.avulsed fragment trapped in the joint (CRITOE)
  • Monteggiaradial head dislocation behind an ulnar #
  • Lateral condyleunder-called; non-union risk
  • NV injuryAIN / brachial artery in supracondylar #
🟢 LITFL · DFTB · Orthobullets
Quick rules
  • AHL → middle third of capitellum
  • RCL → through capitellum, every view
  • Posterior fat pad → always abnormal
  • CRITOE → 1·3·5·7·9·11 (order > age)
  • Trochlea without medial epicondyle → avulsion
  • Effusion + no # → treat as occult fracture
🟢 Radiopaedia · RCH
Neurovascular
  • Document NV status before & after any manipulation
  • AIN (OK sign), median, radial & ulnar nerves
  • Radial pulse & capillary refill — watch the pink-pulseless / white hand
  • Escalate displaced supracondylar # urgently
🔴 red flagPain out of proportion, tense forearm → think compartment syndrome.
🟢 Orthobullets · RCH

ED AI Tutor — ED Reference Series · v0.1 · For clinician education only. Not a substitute for formal radiology reporting, clinical judgment, local guidelines or senior oversight. Paediatric elbow X-rays must always be correlated with the clinical examination.