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Ankle Fracture

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Other Names

  • Ankle Subluxation
  • Dislocated Ankle
  • Subluxed Ankle
  • Dislocated Ankle
  • Trimal fracture
  • Bimal fracture
  • Distal fibular fracture
  • Bimalleolar and bimalleolar-equivalent fractures
  • Posterior malleolus fractures
  • Bosworth fracture-dislocations
  • Open ankle fractures


  • This page describes fractures, subluxations and dislocations of the Ankle Joint


  • Needs to be updated


  • Ankle Fracture
    • More than 250,000 annually in the United States[1]
  • Ankle Fracture-Dislocations
    • Tibiotalar dislocations may occur in 21-36% of ankle fractures[2]
    • Occurs more in males (72%) than female[3]
  • Isolated Dislocations
    • Isolated dislocations without concomitant fracture are rare but do happen[4]
    • Estimated incidence of pure ankle dislocation is 0.065% (13/20,000) in patients presenting with an ankle injury[3]

Lateral ankle XR of open fibular fracture and tibiotalar dislocation
Ankle Fracture Case



  • Ankle fracture refers to fracture of the bones which make up the ankle (talus, tibia, fibula)
  • Dislocation refers to loss of congruence of the joint usually associated with fractures
  • Isolated fractures of the distal fibula, distal tibia, and talus are discussed separately

Ankle Fracture Dislocation

  • More common than isolated dislocations (meaning no associated fractures)
  • Occurs due to abduction force causing displacement of the talus and malleolar fracture[5]

Isolated Dislocation

  • Posteromedial Dislocation
    • caused by maximal plantarflexion, axial load, and inversion of the ankle[6]
    • Often leads to open dislocation
  • Anterior Dislocation[3]
    • Occurs after maximum plantar flexion and ankle inversion allowing anterior movement of the talus
    • May lead to rupture of the anterolateral capsule, anterior talofibular ligament (ATFL), calcaneofibular ligament (CFL), and extensor and peroneal retinaculi
  • Superior Dislocation[3]
    • Forced dorsiflexion and ankle eversion may cause rupture of the tibiofibular syndesmosis and superior movement of the ankle joint

Mechanism of Injury

  • General
    • Most often occur by rotational mechanisms with the external forces transmitted through the foot via the talus to the malleoli
    • Lauge-Hansen ankle fracture classification (see below) attempts to describe injury based on position of foot at time of injury
  • Fracture-dislocations
    • A 2017 systemic review of pure dislocations showed that sporting injuries (31%) and motor vehicle accidents (30%) are the most common causes[3]

Associated Conditions


Risk Factors

  • Medial malleolus hypoplasia
  • Ligamentous laxity
  • Weak peroneal muscles
  • History of ankle sprains
  • Previous ligamentous injury

Differential Diagnosis

Differential Diagnosis Ankle Pain

Clinical Features


  • Mechanism is helpful to identify potential injury patterns
  • Patients endorse pain, swelling, inability to ambulate
  • Patient may describe deformity

Physical Exam: Physical Exam Foot and Ankle

  • Soft tissue swelling, bruising
  • Skin tenting, break in skin may be present
  • Deformity is often obvious
  • Careful, thorough neurovascular examination



  • Standard Radiographs Ankle
    • Includes AP, lateral and mortise views
  • Pre-reduction radiographs
    • Important to rule out trauma mimicking ankle fracture dislocations (i.e. distal tibia fracture, subtalar dislocation)
    • However, do not delay reduction attempt if concern about compromised soft tissue
  • Post-reduction radiographs
    • Should be obtained
    • Useful for: adequacy of reduction, surgical planning and decision making
  • Do not provide adequate assessment of
    • Articular injury
    • Posterior malleolar involvement
    • Osteochondral Lesion size
    • Intra-articular loose bodies
    • Inadequate or malreduction
  • Findings


  • Indications
    • Generally surgeon dependent and topic for research
  • Leung et al found preoperative CT allowed for detection of[7]
    • Posterior malleolar lesions
    • Intra-articular loose bodies
    • Bony avulsions
  • Operative planning
    • Black et al found ankle-fracture dislocations were more likely to be changed than fractures (31% vs 20%)[8]
    • Operative plans are altered in about 25% of ankle fractures due to additional findings on CT[7]


  • Not routinely required
  • Can be used to help characterize soft tissue injuries


Decision making tree for ankle fractures proposed by Michelson and simplified by Ovaska[9]

Lauge-Hansen Ankle Fracture Classification

  • General
    • Developed in 1948 from cadaveric research looking at fracture patterns, foot position and direction of force[10]
    • Widely used but does not predict all ankle-fracture patterns
  • Supination /Adduction (SAD)
    • Talofibular sprain or distal fibular avulsion
    • Vertical medial malleolus and impaction of anteromedial distal tibia
  • Supination /External Rotation (SER)
    • Anterior tibiofibular ligament sprain
    • Lateral short oblique fibula fracture (anteroinferior to posterosuperior)
    • Posterior tibiofibular ligament rupture or avulsion of posterior malleolus
    • Medial malleolus transverse fracture or disruption of deltoid ligament
  • Pronation /Abduction (PAB)
    • Medial malleolus transverse fracture or disruption of deltoid ligament
    • Anterior tibiofibular ligament sprain
    • Transverse comminuted fracture of the fibula above the level of the syndesmosis
  • Pronation /External Rotation (PER)
    • Medial malleolus transverse fracture or disruption of deltoid ligament
    • Anterior tibiofibular ligament disruption
    • Lateral short oblique or spiral fracture of fibula (anterosuperior to posteroinferior) above the level of the joint
    • Posterior tibiofibular ligament rupture or avulsion of posterior malleolus

Danis Weber Classification

  • General
    • First presented by Danis in 1949, then popularized by Weber[11]
    • Classifies ankle fractures into 3 groups based on the level of lateral malleolus fracture seen on radiographs
    • Does not address medial and posterior injury patterns, not specific to ankle fracture-dislocations
    • Commonly referred to as the 'Weber classification'
  • Weber A
    • Infrasyndesmotic, stable
  • Weber B
    • Transsyndesmotic, can be stable or unstable
  • Weber C
    • Suprasyndesmotic, unstable

AO/OTA Classification System

  • 44A: infrasyndesmotic
  • 44B: transsyndesmotic
  • 44C: suprasyndesmotic


Post-reduction and splinting radiograph of trimalleolar fracture.


  • Follow ATLS algorithm when indicated
    • Mechanism of injury will help suggest need for broader evaluation
  • Closed Reduction Ankle
    • Obvious fracture-dislocations should be reduced
    • Most commonly performed in Emergency department
    • Typically requires procedural sedation, intra-articular block
    • Placed in Posterior Short Leg Splint with Stirrup
    • Procedure is usually successful, however soft tissue can block closed reduction[12]



Fluoroscopy status post ORIF of trimalleolar fracture.
  • Indications
    • Talar displacement
    • Bimalleolar fracture
    • Bimalleolar-equivalent fracture
    • Posterior malleolar fracture (> 25% or > 2mm step-off)
    • Bosworth fracture-dislocations
    • Open fractures
    • Nonunion
  • Technique
    • Open reduction, internal fixation
    • Role of external fixation is not well defined

Rehab and Return to Play


  • Needs to be updated

Return to Play

  • Needs to be updated

Prognosis and Complications

Unstable weber B 6 weeks out from injury in a noncompliant patient. Note the significant callous formation.


  • Fracture-dislocations
    • Higher revision (ORIF) rate than nondislocated ankle fractures[13]
    • 82% of patients reported excellent or good outcomes with a mean follow up of 2-6 years[14]
    • More likely to have worse Foot and Ankle Outcome Score (FAOS) compared to non-dislocated fractures[15]
  • Postoperative
    • Patients tend to demonstrate significant improvement in function from 6 months to 1 year following surgery[16]
  • Early reduction helps with[17]
    • Reduced risk of neurovascular and skin complications
    • Releases soft-tissue tension
    • Reduce the time of cartilaginous impingement
    • Prevent or delay to surgery if indicated
  • Factors that may lead to worse outcomes[3]
    • Advanced age
    • Involvement of vascular injury
    • Delay timing for reduction
    • Inferior tibiofibular ligament injury

Acute complications

  • Soft tissue complications
    • Wound dehiscence, skin necrosis and infection are most common complications[18]
    • Increased soft-tissue injury increases risk of postoperative complications when not properly addressed
    • 3 fold increased risk when dislocation is present[19]
    • Delays in treatment of fracture-reduction increases risk of soft tissue complications
  • Malunion or nonunion during reduction
  • Open Fracture
    • Up to 1/3 of fracture-dislocations are open[20]
    • Higher reported incidence of open dislocation when fracture is absent
  • Osteochondral Lesion (OCL)
    • Present in up to 79% of all ankle fractures[21]
    • Risk increases with severity of of injury, notably in fracture-dislocations
    • Odds Ratio of 5.56 for dislocated vs non-dislocated fractures for developing OCL[22]
  • Intra-articular loose bodies
  • Articular Malreduction
    • Major predictive factor affecting outcomes
    • Associated with fracture comminution, poor bone quality, technical errors[23]
    • Higher risk in dislocated vs non-dislocated ankle fractures[24]
  • Posterior malleolar involvement
    • More common in dislocated vs non-dislocated fractures[24]

Late Complications

  • Post Traumatic Ankle Osteoarthritis[25] (PTOA)
    • One study found 14% of patients had PTOA[14]
    • Another study showed up to 63% of patients with ankle fracture-dislocations[26]
  • Stiffness
  • Degenerative changes
  • Joint instability
  • Capsular calcification
  • Chronic pain

See Also




  1. Barrett, JA, Baron, JA, Karagas, MR, Beach, ML. Fracture risk in the U.S. medicare population. J Clin Epidemiol. 1999;52(3):243–249.
  2. Regier M, Petersen JP, Hamurcu A, Vettorazzi E, Behzadi C, Hoffmann M, Großterlinden LG, Fensky F, Klatte TO, Weiser L, Rueger JM, Spiro AS. High incidence of osteochondral lesions after open reduction and internal fixation of displaced ankle fractures: Medium-term follow-up of 100 cases. Injury. 2016 Mar;47(3):757-61.
  3. 3.0 3.1 3.2 3.3 3.4 3.5 Wight L, Owen D, Goldbloom D, Knupp M. Pure Ankle Dislocation: A systematic review of the literature and estimation of incidence. Injury. 2017 Oct;48(10):2027-2034.
  4. Fernandes, T . Mechanism of talo-tibial dislocation without fracture. J Bone Joint Br. 1976;58(B):364–365.
  5. LAUGE N. Fractures of the ankle; analytic historic survey as the basis of new experimental, roentgenologic and clinical investigations. Arch Surg. 1948 Mar;56(3):259-317. PMID: 18874737.
  6. Lamraski, G, Clegg, E. Unusual upward closed tibiotalar dislocation without fracture: a case report. Foot Ankle Surg. 2010;16(2):e44–e46.
  7. 7.0 7.1 Leung, KH, Fang, CX, Lau, TW, Leung, FK. Preoperative radiography versus computed tomography for surgical planning for ankle fractures. J Orthop Surg (Hong Kong). 2016;24(2):158–162.
  8. Black, EM, Antoci, V, Lee, JT. Role of preoperative computed tomography scans in operative planning for malleolar ankle fractures. Foot Ankle Int. 2013;34(5):697–704.
  9. Ovaska, Mikko. "Complications in ankle fracture surgery." Acta Orthopaedica 86.sup358 (2015): 1-35.
  10. Lauge, N . Fractures of the ankle; analytic historic survey as the basis of new experimental, roentgenologic and clinical investigations. Arch Surg. 1948;56(3):259–317.
  11. Danis, R . Les fractures malleolaires: théorie et pratique de l’osteosynthese [Malleolar fractures: Theory and practice of osteosynthesis.]. Paris, France: Masson; 1949.
  12. 14. Ermis, MN, Yagmurlu, MF, Kilinc, AS, Karakas, ES. Irreducible fracture dislocation of the ankle caused by tibialis posterior tendon interposition. J Foot Ankle Surg. 2010;49:166–171
  13. Pincus, D, Veljkovic, A, Zochowski, T, Mahomed, N, Ogilivie-Harris, D, Wasserstein, D. Rate and risk factors for intermediate-term reoperation after ankle fracture fixation: a population-based cohort study. J Orthop Trauma. 2017;31:e315–e320.
  14. 14.0 14.1 Lindsjo, U . Operative treatment of ankle fracture-dislocations: a follow-up study of 306/321 consecutive cases. Clin Orthop Relat Res. 1985(199):28–38.
  15. Sculco, PK, Lazaro, LE, Little, MM. Dislocation is a risk factor for poor outcome after supination external rotation type ankle fractures. Arch Orthop Trauma Surg. 2016;136(1):9–15.
  16. Nilsson, G, Jonsson, K, Ekdahl, C, Eneroth, M. (2007) Outcome and quality of life after surgically treated ankle fractures in patients 65 years or older. BMC Musculoskelet Disord. 8:127
  17. Payne, R, Kinmont, JC, Moalypour, SM. Initial management of closed fracture-dislocations of the ankle. Ann R Coll Surg Engl. 2004;86(3):177–181.
  18. Stufkens, SA, Knupp, M, Horisberger, M, Lampert, C, Hintermann, B. Cartilage lesions and the development of osteoarthritis after internal fixation of ankle fractures: a prospective study. J Bone Joint Surg Am. 2010;92(2):279–286.
  19. Kelly, PJ, Peterson, LF, Compound dislocation of the ankle without fracture. Am J Surg. 1962;103(2):170–172.
  20. Kelly, PJ, Peterson, LF, Compound dislocation of the ankle without fracture. Am J Surg. 1962;103(2):170–172.
  21. O’Loughlin, PF, Heyworth, BE, Kennedy, JG. Current concepts in the diagnosis and treatment of osteochondral lesions of the ankle. Am J Sports Med. 2010;38(2):392–404.
  22. Regier, M, Petersen, JP, Hamurcu, A. High incidence of osteochondral lesions after open reduction and internal fixation of displaced ankle fractures: medium-term follow-up of 100 cases. Injury. 2016;47(3):757–761.
  23. Berkes, MB, Little, MT, Lazaro, LE. Articular congruity is associated with short-term clinical outcomes of operatively treated SER IV ankle fractures. J Bone Joint Surg Am. 2013;95(19):1769–1775.
  24. 24.0 24.1 Warner, SJ, Schottel, PC, Hinds, RM, Helfet, DL, Lorich, DG. Fracture-dislocations demonstrate poorer postoperative functional outcomes among pronation external rotation IV ankle fractures. Foot Ankle Int. 2015;36(6):641–647.
  25. Wang YT, Wu XT, Chen H. Pure closed posteromedial dislocation of the tibiotalar joint without fracture. Orthop Surg. 2013 Aug;5(3):214-8
  26. Regan, DK, Gould, S, Manoli, A III, Egol, KA. Outcomes over a decade after surgery for unstable ankle fracture: functional recovery seen 1 year postoperatively does not decay with time. J Orthop Trauma. 2016;30(7):e236–e241
Created by:
John Kiel on 7 July 2019 08:19:29
Last edited:
1 May 2024 12:40:37