Trigger Thumb
SUMMARY: Overview of Paediatric Trigger Thumb
Background
Flexion deformity of the interphalangeal joint.
The cause is unknown and it does not present at birth.
60% of trigger thumbs resolve spontaneously by 12 months of age.
Trigger thumbs do not impede the early use of the hand.
Approximately 1:300 kids by the age of 12 months
25% are bilateral
Note: Trigger finger is rare and is generally associated with other disorders. A referral to a Paediatric Orthopaedic Specialist is required.
Cause
? Thickening of flexion tendon > nodule forming
Different cause to adult trigger thumb, anti-inflammatory not helpful in kids
Most are idiopathic, not obviously linked to other MSK conditions
Assessment
History:
Age
Trauma to the hand or fingers
Appropriate developmental milestones
Family history of trigger fingers or hand deformities
Examination:
Weight, height, and percentile for age
Flexed position of thumb
A palpable nodule may be present on the tendon of the metacarpal joint on the palmer side
An audible pop or click on extension
A palpable click on extension
Examine both hands
X-ray is not required but is safe if there is a traumatic dislocation-type history
Management
Splinting or other therapies are of no benefit in the first 12 months.
Observation is a recommended first-line treatment and spontaneous recovery more likely in under age of 2
Gentle stretching and massage
Night time splinting
Ask the parents to keep a photographic diary.
Surgery is ideally attended between 2 to 3 years of age.
Successful surgical correction after 3 years may still have residual contracture.
Referral
Consider referral to paediatric orthopaedic specialist, or a specialist hand surgeon, if:
the trigger thumb persists past 18 months of age.
the child complains of pain, or is not using the hand efficiently.
Attach a photograph, if possible.
Information
Trigger Thumb Fact Sheet – The Sydney Children's Hospitals Network
20 min audio podcast on Trigger Thumb from Kids Hospital Colorado
