Korean J Sports Med.  2021 Sep;39(3):127-130. 10.5763/kjsm.2021.39.3.127.

Irreducible Anterior Subluxation of the Ankle Joint Caused by Os Trigonum and Transverse Ligament: A Case Report

  • 1Department of Orthopedic Surgery, Armed Forces Yangju Hospital, Yangju, Korea


Ankle joint is a stable mortise structure, therefore pure ankle dislocation without ankle fracture is rare. Several adjacent anatomical structures have been reported as a cause of irreducible ankle dislocation. Author report a case of successful treatment of irreducible anterior subluxation of the ankle joint due to os trigonum and transverse ligament by closed reduction under anesthesia, and a review of the literature as well.


Ankle joint; Joint dislocations; Talus; Ligaments


  • Fig. 1 Initial right ankle plain radiographs showing anterior subluxation of the ankle joint. Note that the ankle is in full plantar flexion state and os trigonum is present.

  • Fig. 2 Initial magnetic resonance imaging of right ankle after several trials of manual reduction at emergency room. Note the transverse ligament (arrow-heads) between posterior talar body and os trigonum.

  • Fig. 3 Intraoperative ankle plain radiograph showing stable mortise structure.

  • Fig. 4 Standing ankle plain radiographs of postoperative 3 months.

  • Fig. 5 Illustration of posterior ankle ligament structures.


1. Wight L, Owen D, Goldbloom D, Knupp M. 2017; Pure Ankle Dislocation: A systematic review of the literature and estimation of incidence. Injury. 48:2027–34. DOI: 10.1016/j.injury.2017.08.011. PMID: 28826653.
2. Natoli RM, Summers HD. 2015; Irreducible ankle fracture-dislocation due to tibialis anterior subluxation: a case report. J Foot Ankle Surg. 54:268–72. DOI: 10.1053/j.jfas.2014.11.012. PMID: 25618805.
3. Connors JC, Coyer MA, Hardy MA. 2016; Irreducible Ankle Fracture Dislocation Due to Tibialis Posterior Tendon Interposition: A Case Report. J Foot Ankle Surg. 55:1276–81. DOI: 10.1053/j.jfas.2015.06.014. PMID: 26243721.
4. Hsiao KC, Tu CH. 1994; Irreducible fracture dislocation of the ankle: report of two cases. J Formos Med Assoc. 93 Suppl 3:S161–5. PMID: 7606175.
5. Georgilas I, Mouzopoulos G. 2008; Anterior ankle dislocation without associated fracture: a case with an 11 year follow-up. Acta Orthop Belg. 74:266–9. PMID: 18564487.
6. Segal LS, Lynch CJ, Stauffer ES. 1992; Anterior ankle dislocation with associated trigonal process fracture. A case report and literature review. Clin Orthop Relat Res. 171–6. DOI: 10.1097/00003086-199205000-00028. PMID: 1563151.
7. Irving D, Geers B, Lawrence B. 2020; Isolated Posterior Medial Ankle Dislocation with Associated Os Trigonum Dislocation after Low-Energy Mechanism. Case Rep Orthop. 2020:1–6. DOI: 10.1155/2020/5026058. PMID: 32047686. PMCID: PMC7007941.
8. Grogan DP, Walling AK, Ogden JA. 1990; Anatomy of the os trigonum. J Pediatr Orthop. 10:618–22. DOI: 10.1097/01241398-199009000-00009. PMID: 2394815.
9. Gursoy M, Dag F, Mete BD, Bulut T, Uluc ME. 2015; The anatomic variations of the posterior talofibular ligament associated with os trigonum and pathologies of related structures. Surg Radiol Anat. 37:955–62. DOI: 10.1007/s00276-015-1428-5. PMID: 25604649.
10. Golano P, Vega J, de Leeuw PA, et al. 2016; Anatomy of the ankle ligaments: a pictorial essay. Knee Surg Sports Traumatol Arthrosc. 24:944–56. DOI: 10.1007/s00167-016-4059-4. PMID: 27052302. PMCID: PMC2855022.
11. Taylor DC, Englehardt DL, Bassett FH 3rd. 1992; Syndesmosis sprains of the ankle. The influence of heterotopic ossification. Am J Sports Med. 20:146–50. DOI: 10.1177/036354659202000209. PMID: 1558241.
Full Text Links
  • KJSM
export Copy
  • Twitter
  • Facebook
Similar articles
Copyright © 2024 by Korean Association of Medical Journal Editors. All rights reserved.     E-mail: koreamed@kamje.or.kr