Sacral dimple

Sacral dimples are a clinical and radiological feature that is associated with occult spinal dysraphism (e.g. tethered cord syndrome) but are more frequently a non-significant isolated finding.

Epidemiology

Common in healthy children (~5%) ¹.

Pathology

Simple sacral dimples have the following features ¹:

• <5 mm in diameter
• <2.5 cm from the anus
• midline without visible drainage
• not associated with other cutaneous stigmata of spinal dysraphism (e.g. hairy tuft, rudimentary tail, haemangioma)

Radiographic features

Ultrasound

Ultrasound is the most commonly used modality, as well as being the modality of choice in neonatal assessment. It is used to assess whether there is any communication with the vertebral column / spinal canal. 

Differential diagnosis

• dorsal dermal sinus
• pilonidal sinus