Os trigonum
Last revised by Daniel J Bell on 31 Jul 2024
Citation, DOI, disclosures and article data
Citation:
Jones J, Bell D, Weerakkody Y, et al. Os trigonum. Reference article, Radiopaedia.org (Accessed on 07 Sep 2024) https://doi.org/10.53347/rID-10194
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rID:
10194
Article created:
22 Jul 2010,
Jeremy Jones ◉
Disclosures:
At the time the article was created Jeremy Jones had no recorded disclosures.
View Jeremy Jones's current disclosures
Last revised:
31 Jul 2024,
Daniel J Bell ◉
Disclosures:
At the time the article was last revised Daniel J Bell had no financial relationships to ineligible companies to disclose.
View Daniel J Bell's current disclosures
Revisions:
34 times, by
20 contributors -
see full revision history and disclosures
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Synonyms:
- Os tali accessorium
- Os intermedium tarsi
- Os tali secundarium
- Ossa trigona
The os trigonum (plural: ossa trigona) is one of the ossicles of the foot and can be mistaken for a fracture.
It sits posterior to the talus on the lateral foot radiograph and represents a failure of fusion of the lateral tubercle of the posterior process. It is estimated to be present in ~7% of adults 1. Bilateral ossa trigona are seen in 2% of individuals 3. The ossicle usually forms between 7-13 years of age and fuses with the talus in a majority of patients by approximately age 17 years old 4, otherwise persisting as an os trigonum.
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Related pathology
Differential diagnosis
General imaging differential considerations include:
See also
Quiz questions
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References
- 1. Cerezal L, Abascal F, Canga A et al. MR Imaging of Ankle Impingement Syndromes. AJR Am J Roentgenol. 2003;181(2):551-9. doi:10.2214/ajr.181.2.1810551 - Pubmed
- 2. Karasick D & Schweitzer M. The Os Trigonum Syndrome: Imaging Features. AJR Am J Roentgenol. 1996;166(1):125-9. doi:10.2214/ajr.166.1.8571860 - Pubmed
- 3. Uzel M, Cetinus E, Bilgic E, Karaoguz A, Kanber Y. Bilateral Os Trigonum Syndrome Associated with Bilateral Tenosynovitis of the Flexor Hallucis Longus Muscle. Foot Ankle Int. 2005;26(10):894-8. doi:10.1177/107110070502601017 - Pubmed
- 4. Incidence and Fusion of Os Trigonum in a Healthy Pediatric Population. (2017) Journal of Pediatric Orthopaedics. doi:10.1097/BPO.0000000000001016 - Pubmed
Incoming Links
Articles:
Cases:
- Os trigonum syndrome
- Talocalcaneal coalition
- Os supratalare
- Accessory ossicles of the foot (illustration)
- Os trigonum syndrome
- Os trigonum and unfused apophysis of the proximal 5th metatarsal
- Subtalar osteoarthritis - bilateral
- Displaced os trigonum
- Achilles tendinopathy and peritendonitis
- Haglund syndrome
- Extra-articular intramalleolar triplane fracture
- Osteochondritis dissecans
- Extra-articular calcaneal fracture
- Ankle fracture - Weber C
- Os trigonum
- Accessory ossicles of the foot
- Posterior talar process fracture
- Normal foot series
- Osgood-Schlatter disease
- Maisonneuve fracture
Multiple choice questions:
Related articles: Anatomy: Lower limb
- skeleton of the lower limb
- joints of the lower limb
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hip joint
- ligaments
- muscles
- additional structures
- hip joint capsule
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hip bursae
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