Pseudosubluxation

 

Cervical pseudosubluxation

 

Definition

 

Relative translation of (typically) C2 on C3

- Physiological variant in children up to 8

 

Subluxation of up to 4 mm

- C2/3 in 40% children

- C3/4 14%

 

Reduces with extension

 

Aetiology

 

Horizontal facet joints

- flat orientation of pediatric facets and laxity of ligaments

- become more vertical with age

 

Diagnosis

 

1. Swischuk's Line

- drawn along spinolaminar line C1 & C3

- C2 should be within 1.5 - 2mm of this line

 

Swishuks line

 

2. Pseudosubluxation will reduce with extension

 

Example in Paediatric Imaging Radiology Textbook