Two patients presented with painful heels. The first was relieved by excision of the os trigonum from each heel. The second was relieved by local steroid injection. The os trigonum is not always an insignificant roentgenographic finding, and fracture of the posterior process of the talus does occur and may in time resemble an os trigonum.
Ecker ML, Ritter MA, Jacobs BS. The Symptomatic Os Trigonum. JAMA. 1967;201(11):882-884. doi:10.1001/jama.1967.03130110108037