Courtesy: Prof Shital Parikh MD, Cincinnati Childeren’s Hospital, Philadelphia, PN

Part 1: Fracture Mimickers in Children

1. Irregular Ossification – A Common Trap

Pediatric ossification centers are irregular and may mimic fractures.
The elbow is particularly challenging due to multiple ossification centers.
Familiarity with:
- Order of appearance
- Timing of fusion
- Normal variants
  is essential to avoid misdiagnosis.

Key Strategy:

When in doubt, obtain a contralateral X-ray for comparison.

2. Multi-Partite Apophysis

Olecranon may ossify from multiple centers.
Can resemble fracture in acute trauma.
Bilateral comparison helps differentiate normal from fracture.

3. Lateral Epicondyle Ossification

Appears transiently.
May mimic fracture on lateral view.
Short window of visibility ? easily mistaken.

4. Irregular Ossification vs Osteochondritis Dissecans (OCD)

Seen commonly in the distal femur.

Differentiation Based on Age:

< 8 years ? usually irregular ossification
12 years ? usually OCD
8–12 years ? grey zone (clinical judgment + MRI)

MRI Clues for Irregular Ossification:

No cartilage breach
No fluid beneath lesion
Tends to resolve with observation

5. Patella Variants

Normal irregular patellar ossification
Bipartite patella (often superolateral and bilateral)
Dorsal defect of patella (benign)

May mimic:

Osteomyelitis
Osteochondral fracture

6. Epiphyseal Variants

Possible normal findings:

Cleft epiphysis
Double epiphysis
Pseudo-epiphysis
Notched epiphysis
Wedge-shaped epiphysis
Undulating physis

Rotation of limb can create illusion of fracture lines.

7. Fifth Metatarsal Apophysis

Apophysis runs longitudinally.
Fracture line runs transversely.
Orientation helps distinguish fracture from normal apophysis.

8. Accessory Ossicles

Common around:

Ankle
Foot
Wrist

Examples:

Os peroneum
Medial malleolar ossicle
Bipartite navicular

These may be:

Normal variants
Or fractures through accessory ossicle

Clinical correlation is essential.

9. Growth Variants

Supracondylar spur (points toward elbow; unlike osteochondroma)
Postero-medial distal femoral irregularity
Deltoid insertion irregularity
Dorsal patellar defect

Often mistaken for tumors.

10. Nutrient Channels

Can resemble hairline or greenstick fractures.
Must differentiate carefully.

11. Infection or Tumor Mimicking Fracture

Red Flags:

Fever
Increasing swelling
Systemic illness
Disproportionate symptoms

Cases discussed:

Osteomyelitis following trivial trauma
Osteosarcoma initially diagnosed as fracture

Clinical suspicion is critical.

12. Non-Accidental Trauma (Child Abuse)

Must consider in:

Infants
Multiple fractures
Fractures at different stages of healing
Rib, scapular, distal clavicle fractures
Corner or bucket-handle metaphyseal fractures

Important:

Avoid both under-diagnosis and over-diagnosis
Consider metabolic or collagen disorders

Part 2: Missed Fractures in Children

Prospective data showed:

~10% error rate in pediatric fracture interpretation.
High discordance between ED physician and radiologist readings.

Commonly Missed Areas:

Ankle
Foot
Wrist
Hand
Elbow

Distal Tibia & Ankle Injuries

Intra-articular fractures often underestimated on X-ray.
CT scan changes:
- Fracture pattern (46%)
- Measured displacement (39%)
- Treatment plan (25%)

Low Threshold for CT:

Transitional fractures
Salter-Harris III & IV
Intra-articular injuries

Complex Tibial Shaft + Intra-Articular Fracture

Focus on obvious shaft fracture may lead to missed ankle fracture.
CT scan essential in suspicious cases.

Deep MCL Avulsion

May appear as small fragment.
Persistent pain despite conservative treatment.
Surgical fixation may be required.

Missed Osteochondral Fractures

Particularly after patellar dislocation.
Cartilage fragments may be hidden in posterior gutter.
MRI essential for diagnosis.

Tibial Spine (ACL Avulsion) – Cartilaginous Injuries

May not be visible on X-ray.
MRI shows displaced cartilaginous avulsion.
Late diagnosis complicates management.

Bipartite Patella vs Osteochondral Fracture

Bipartite usually superolateral and bilateral.
True fracture correlates with mechanism and symptoms.

Proximal Tibial Posterior Fractures

Subtle on X-ray.
Risk of:
- Vascular injury
- Compartment syndrome

MRI helpful.

Seymour Fracture (Distal Phalanx)

Open physeal fracture.
Nail plate lies over nail fold (not under).
Requires:
- Nail removal
- Debridement
- Reduction
- Nail bed repair
- Antibiotics

Complications if missed:

Osteomyelitis
Nail deformity
Growth arrest

Phalangeal Neck & Condylar Fractures

May remodel, but improper treatment causes:
- Deformity
- Contracture
- Motion restriction

Clinical examination (finger cascade) is essential.

Elbow “TRASH” Lesions

(Trauma Radiographic Appearance Seems Harmless)

Commonly Missed:

Monteggia fractures
Radial head fractures
Medial epicondyle incarceration
Coronoid fractures
Lateral condyle fractures

Posterior Fat Pad Sign

Always abnormal.
Suggests intra-articular injury.

Monteggia Injury

Look for radial head alignment.
Draw line along radial shaft ? must intersect capitellum.
Always evaluate radio-capitellar relationship.

Missed Monteggia ? complex reconstructive surgery.

Radial Head Fractures

Can progress to:
- Posterior subluxation
- Rapid arthritis

Late cases may require radial head excision.

Medial Condyle Fracture

May rotate 180° if missed.
Requires surgical fixation.

Coronoid Fracture

Provides elbow stability.
Often cartilaginous in younger children.
Requires fixation if unstable.

Arthrogram for Lateral Condyle Fractures

Helps assess articular hinge.
Determines need for open reduction.

Transphyseal Fracture vs Elbow Dislocation

Radio-capitellar alignment intact ? transphyseal fracture.
Both relationships disrupted ? dislocation.

Imaging Strategy Summary

CT Scan

Indicated for:

Intra-articular fractures
Transitional fractures
Surgical planning

MRI