Lateral Condyle Fractures - Pediatric

Key Anatomical Points

The lateral condyle includes:

• Capitellum (articulates with radial head)
• Lateral portion of trochlea (variable extent)
• Lateral epicondyle (common extensor origin)

Blood supply: Enters posteriorly. The fragment has NO anterior blood supply once fractured. Protect posterior soft tissues during surgery.

Deforming forces: Extensor muscles (attached to lateral epicondyle) pull the fragment distally and rotate it, causing displacement.

Fracture Configuration

The fracture line runs:

• Through the lateral metaphysis
• Across the physis (usually posterolaterally)
• Into the articular surface of the trochlea/capitellum

Classification based on exit point: Milch Type I exits lateral to trochlear ridge (stable). Milch Type II exits through trochlear ridge (potentially unstable).

Weiss/Jakob Classification (Most Clinically Useful)

This classification is more practical for guiding treatment than Milch.

Milch Classification (Anatomical)

Type II is more common. The trochlear ridge is the key landmark. If the fracture exits through it, the ulnohumeral articulation may be unstable.

Radiological Investigations

Internal oblique view is particularly helpful as it places the fracture line in profile.

MRI and Arthrography

When to consider:

• Occult fracture suspected (effusion but no visible fracture)
• Cartilage extent of fracture unclear
• To assess articular congruity

Arthrogram: Contrast into elbow joint can outline cartilage extent. Useful intraoperatively or to clarify displacement.

Non-Operative Management (Weiss Type I)

Indications: Displacement less than 2mm, intact cartilage hinge.

Treatment: Long arm cast in 90 degrees elbow flexion.

Follow-up: Weekly X-rays for first 3 weeks. If any displacement occurs, convert to ORIF.

Duration: Cast for 4-6 weeks until union confirmed.

Key point: Close follow-up is mandatory. Up to 20% of initially non-displaced fractures may displace.

Operative Management (Weiss Type II-III)

Indication: Displacement greater than 2mm or any rotation of fragment.

Approach: Lateral/Kocher approach. STAY ANTERIOR. Do NOT dissect posteriorly (blood supply).

Technique: Open reduction through direct visualization. Reduce articular surface anatomically. Fix with 2 smooth K-wires (divergent). Check reduction under fluoro.

Post-op: Long arm cast for 4-6 weeks. Remove pins at 4 weeks if union proceeding.

ORIF Technique for Lateral Condyle

Position: Supine with arm on hand table.

Approach: Lateral/Kocher interval between anconeus and ECU.

Critical step: Visualize the articular surface from ANTERIOR. Do NOT strip soft tissues from posterior fragment.

Reduction: Reduce articular surface anatomically. The metaphyseal reduction usually follows.

Fixation: Two smooth K-wires, usually 1.6mm. Divergent configuration. Cross fracture site but avoid olecranon fossa.

Percutaneous Pinning

When appropriate: Minimally displaced fractures where surgeon concerned about displacement but reduction adequate.

Technique: Fluoro-guided pin placement. Two pins from lateral epicondyle directed proximally and medially.

Limitation: Cannot visualize articular reduction directly. Best reserved for near-anatomic alignment.

Management of Nonunion

Early nonunion (less than 3-6 months): ORIF with bone grafting still possible. Better outcomes than late reconstruction.

Established nonunion (greater than 6 months): In situ fixation with bone grafting or corrective osteotomy. The nonunion may be too sclerotic for direct healing without osteotomy.

Late nonunion with cubitus valgus: May require supracondylar osteotomy for angular correction plus ulnar nerve transposition.

Cubitus Valgus Management

Cause: Lateral condyle nonunion leads to lateral physeal arrest with continuation of medial growth.

Progressive valgus stretches ulnar nerve leading to tardy ulnar nerve palsy.

Treatment: Supracondylar or distal humeral osteotomy to correct carrying angle. Ulnar nerve transposition if neuropathy present.

Late Presenting Fractures

Challenge: Fragment may be fibrosed in displaced position.

Less than 3 weeks: Still reasonable to attempt ORIF.

Greater than 3-4 weeks: In situ fixation may be considered if functional limitation, but outcomes less predictable.

Much later: Better to accept position and address deformity if it develops.