Hitchhiker thumb deformity

Last revised by Mostafa Elfeky on 15 Aug 2023

Citation, DOI, disclosures and article data

Citation:

Shetty A, Elfeky M, Bilodeau L, et al. Hitchhiker thumb deformity. Reference article, Radiopaedia.org (Accessed on 19 Apr 2024) https://doi.org/10.53347/rID-28019

DOI:

https://doi.org/10.53347/rID-28019

Permalink:

https://radiopaedia.org/articles/28019

rID:

28019

Article created:

5 Mar 2014, Aditya Shetty

Disclosures:

At the time the article was created Aditya Shetty had no recorded disclosures.

View Aditya Shetty's current disclosures

Last revised:

15 Aug 2023, Mostafa Elfeky ◉

Disclosures:

At the time the article was last revised Mostafa Elfeky had no financial relationships to ineligible companies to disclose.

View Mostafa Elfeky's current disclosures

Revisions:

16 times, by 12 contributors - see full revision history and disclosures

Systems:

Musculoskeletal

Sections:

Signs

Tags:

shetty, refs

Synonyms:

Z-thumb
Z-shaped thumb
Duckbill thumb
Duck-bill thumb
Hitchhiker's thumb
Hitchhiker's thumbs
Hitchhiker thumbs

Hitchhiker thumb deformity is a musculoskeletal manifestation of rheumatoid arthritis presenting in the thumb, with the combination of:

flexion of the metacarpophalangeal (MCP) joint
hyperextension of the interphalangeal (IP) joint

Terminology

Hitchhiker thumb deformity, also known as Z-thumb or duckbill thumb, is used to both describe the appearance of the thumb on physical examination and also the corresponding radiographic appearance. It is similar to how a person would normally angulate and hold out the thumb with the intention to hitchhike. It is one of the musculoskeletal manifestations of rheumatoid arthritis in the hand although not entirely specific for this diagnosis.

The sign is also used in obstetric ultrasound and on pediatric radiographs to describe the appearance of the fingers in diastrophic dysplasia.