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Ankle Fracture/Dislocation, Emergency Medicine

Basics

Description

- Eversion injury: Medial ankle distraction and lateral ankle compression - Avulsion fracture of medial malleolus - Oblique fracture of the fibula

- Epidemiology - Most ankle fractures are malleolar - Common in young male and 50-70 yr old female - Associated with cigarette use and high BMI

- Assess the skin for swelling, ecchymosis, skin tenting, disruption, or ischemia - Careful evaluation of distal neurovascular status: - Capillary refill - Palpation or Doppler of DP and PT pulses

- Palpate proximal fibula for tenderness, especially when medial malleolus or deltoid ligament tenderness is present: - Peroneal nerve is at risk for injury with a Maisonneuve fracture: - Wraps around the fibular head - Test anterior tibialis and extensor hallucis longus - Assess sensation in the 1st web space

- Closed ankle fractures: - Dislocations should be reduced promptly to prevent complications - Apply posterior splint to immobilize foot in 90 ° angle with the application of bulky dressings and covered by a volar posterior and coaptation (U-shaped stirrup) splint - Sugar tong (coaptation) can be added for mediolateral support

- Open fractures: - Cefazolin: 2 g loading dose (peds: 50 mg/kg) IV - Gentamicin: 5-7 mg/kg q24h (peds: 2.5 mg/kg q8h) IV - Vancomycin: 1 g loading dose (10 mg/kg in children) if penicillin allergic - Tetanus toxoid if indicated

Common mechanisms and injury patterns of the ankle:

  • Mechanism of injury:Inversion injury: Lateral ankle distraction and medial ankle compressionAvulsion fracture of the lateral malleolusOblique fracture of the medial malleolusEversion injury: Medial ankle distraction and lateral ankle compressionAvulsion fracture of medial malleolusOblique fracture of the fibulaExternal rotation injury:Disruption of the tibiofibular syndesmosis, or a fibular fracture above the plafondAnterior or posterior tibial fracture with separation of the distal tibia and fibula (unstable fracture)Inversion and external rotation (Maisonneuve fracture):Medial malleolus avulsion fracture or deltoid ligament tearDisruption of the tibiofibular syndesmosisOblique fracture of the proximal fibulaInversion and dorsiflexion (snowboarders' fracture):Fracture of the lateral process of the talus
  • EpidemiologyMost ankle fractures are malleolarCommon in young male and 50-70 yr old femaleAssociated with cigarette use and high BMI
  • Ankle fractures in children often involve the physis (growth plate):May result in angular deformity from growth plate injuryAssociated with sports requiring sudden changes in direction and obese childrenIn children <10 yr old, growth plate is weaker than epiphysis
  • Tillaux fracture: Salter-Harris type III injury of the anterolateral tibial epiphysis external rotation of the foot
  • Triplane fracture: Uncommon fracture of distal tibia with fracture lines in 3 distinct planes (coronal, transverse, sagittal)

Diagnosis

Signs and Symptoms

  • History of trauma
  • Local ankle pain, swelling, deformity
  • Inability to bear weight
  • Soft tissue injury, swelling, ecchymosis, skin tenting, skin blanching
  • Neurovascular compromise:Diminished capillary refillDiminished posterior tibialis (PT) or dorsalis pedis (DP) pulses
  • Limited range of motion

History

  • Discover the position of the ankle at the time of injury and area of most significant pain
  • Determine if patient was able to bear weight immediately or if he or she needed assistance to walk afterward
  • Ask if the patient heard audible "pop" or "snap," as this may indicate partial or full tendon rupture

Physical Exam

  • Ottawa Ankle Rules (OAR), 100% sensitive: Decision tool for ordering radiographs in patients with suspected injury to the ankle and midfoot:Malleolar zone (if any finding is present, then ankle radiographs are indicated):Bony tenderness at the posterior edge or distal 6 cm of either malleoli (points A and B)Inability to bear weight for 4 consecutive steps both immediately after the injury and in EDMidfoot zone (if either finding is present, then foot radiographs are indicated):Bony tenderness at the base of the 5th metatarsal (point C)Bony tenderness of the navicular (point D)Inability to bear weight for 4 consecutive steps both immediately after the injury and in EDConsidered a reliable tool in children >5 yr
  • Assess the skin for swelling, ecchymosis, skin tenting, disruption, or ischemia
  • Careful evaluation of distal neurovascular status:Capillary refillPalpation or Doppler of DP and PT pulses
  • Palpate proximal fibula for tenderness, especially when medial malleolus or deltoid ligament tenderness is present:Peroneal nerve is at risk for injury with a Maisonneuve fracture:Wraps around the fibular headTest anterior tibialis and extensor hallucis longusAssess sensation in the 1st web space

Diagnosis Tests & Interpretation

Imaging

  • Radiography:Evaluate the mortise view for widening: Distance between talus to the medial and lateral malleoli should be uniform
  • Unstable ankle fractures or dislocations require post reduction radiographs in all 3 planes after splintingAnteroposterior (AP), lateral, and mortise (AP with a 20 ° lateral angle)
  • AP and lateral radiographs of the tibia and fibula are indicated if a Maisonneuve fracture is suspected clinically
  • Stress testing of the ligaments in a painful ankle is unnecessary in the ED if the patient will be re-examined in 3-7 days
  • Stress radiographs of the ankle are usually unnecessary acutely
  • CT scan or MRI:Assess the degree of injury to the tibial plafond and associated ligamentous injury

Diagnostic Procedures/Surgery

N/A

Differential Diagnosis

  • Ankle sprain
  • Achilles tendon injury
  • Os trigonum fracture
  • 5th metatarsal fracture (Jones fracture)
  • Peroneal tendon dislocation or injury
  • Talar fractures
  • Talar dome fracture/lesion
  • Subtalar dislocations
  • Calcaneal fractures
  • Foot fractures
  • Ankle diastasis
  • Rattlesnake envenomation
  • Injury to the growth plates may not be apparent on plain radiographs
  • Consider splint immobilization, nonweight-bearing status, and orthopedic referral if clinical suspicion warrants, even in the setting of negative radiographs
  • CT scan or MRI may be warranted to delineate the extent of the injury
  • Inform parents of the possibility of growth abnormalities in patients with injury to the physis

Treatment

Pre-Hospital

  • Immobilize with soft splint to reduce pain, bleeding, and further injury
  • Cautions:Traction devices are usually unnecessary:Contraindicated with open injuriesProtruding bone should not be reduced; the wound should be covered with a clean dressing

Initial Stabilization/Therapy

  • Nonweight bearing
  • Ice
  • Compression
  • Elevation

Ed Treatment/Procedures

  • Ankle fracture:All ankle fractures or dislocations require orthopedic referralOpen ankle fractures:Remove contaminantsApply moist sterile dressingAssess tetanus immunityAntibioticsEmergent orthopedic consultationClosed ankle fractures:Dislocations should be reduced promptly to prevent complicationsApply posterior splint to immobilize foot in 90 ° angle with the application of bulky dressings and covered by a volar posterior and coaptation (U-shaped stirrup) splintSugar tong (coaptation) can be added for mediolateral supportStable injury: (one-sided nondisplaced malleolar fracture without ligamentous injury)Isolated injury to the lateral malleolus without medial involvement is virtually always stableApply posterior splintUnstable injury: (both sides of the ankle are injured i.e., bi- or trimalleolar fractures)Urgent orthopedic consultationPosterior splint as in stable injuriesMay require open reduction and internal fixation (ORIF) emergently before significant swelling developsNeurovascular injury requires emergent orthopedic consultation
  • Ankle dislocations:Closed reduction should be performed as rapidly as possible to minimize ischemia to the skin and reduce the risk of avascular necrosis of the talusSkin tenting and evidence of neurovascular compromise are indications for immediate reduction, even prior to radiographsMost ankle dislocations require ORIFAfter reduction, place a posterior splint

Medication

  • Closed fractures:Primarily analgesics (opioids)
  • Dislocations or displaced fractures requiring closed reduction consider:Short-acting benzodiazepine (midazolam 0.05-0.1 mg/kg IV) or barbiturate (methohexital 1-1.5 mg/kg IV) with opioid analgesic
  • Open fractures:Cefazolin: 2 g loading dose (peds: 50 mg/kg) IVGentamicin: 5-7 mg/kg q24h (peds: 2.5 mg/kg q8h) IVVancomycin: 1 g loading dose (10 mg/kg in children) if penicillin allergicTetanus toxoid if indicated

Follow-Up

Disposition

Admission Criteria

  • Unstable ankle fractures require urgent orthopedic consultation and may require admission
  • Open ankle fractures and dislocations should be admitted for debridement, irrigation, and IV antibiotics
  • Ankle dislocations that are treated with either open or closed reduction
  • Concern for compartment syndrome or neurovascular injury

Discharge Criteria

Simple nondisplaced stable ankle fractures without neurovascular compromise may be splinted for immobilization and discharged

Follow-Up Recommendations

  • Splinting
  • Elevation of affected lower extremity
  • Fitted for crutches and shown how to use them
  • Placed on nonweight-bearing status of affected joint, until seen by orthopedist

Pearls and Pitfalls

  • To reduce a dislocated ankle, partial flexion of knee of affected limb will decrease tension on Achilles tendon and ankle
  • Differentiate between ankle fracture and subtalar fracture on physical exam: While the latter is rare, it is also rarely reducible
  • Remember to look for other injuries including lumbar spine, hip, tibia, fibula, especially the proximal fibular neck, and foot

Additional Reading

  • Bachmann LM. Accuracy of Ottawa ankle rules to exclude fractures of the ankle and mid-foot: systematic review. Br Med J. 2003;326:417.
  • Blackburn, EW, Aronsson DD, Rubright JH, et al. Ankle fractures in Children. J Bone Joint Surg Am. 2012;94(13):1234-1244.
  • Dowling S, Spooner CH, Liang Y, et al. Accuracy of Ottawa Ankle Rules to exclude fractures of the ankle and midfoot in children: A meta-analysis. Acad Emerg Med. 2009;16:277-287.
  • Koehler SM, Eiff P, et al. Overview of ankle fractures in adults. UpToDate.com. 2012 Oct.
  • Slimmon D, Brukner P. Sports ankle injuries: Assessment and management. Aust Fam Physician. 2010;39(1-2):18-22.

See Also (Topic, Algorithm, Electronic Media Element)

Ottawa Ankle Rules Figure

Codes

ICD9

  • 824.0 Fracture of medial malleolus, closed
  • 824.8 Unspecified fracture of ankle, closed
  • 824.9 Unspecified fracture of ankle, open
  • 824.2 Fracture of lateral malleolus, closed
  • 824.1 Fracture of medial malleolus, open
  • 824.3 Fracture of lateral malleolus, open
  • 824.5 Bimalleolar fracture, open
  • 824.6 Trimalleolar fracture, closed
  • 824.7 Trimalleolar fracture, open
  • 824 Fracture of ankle

ICD10

  • S82.56XA Nondisp fx of medial malleolus of unsp tibia, init
  • S82.66XA Nondisp fx of lateral malleolus of unsp fibula, init
  • S82.899A Oth fracture of unsp lower leg, init for clos fx
  • S82.843A Displaced bimalleolar fracture of unsp lower leg, init
  • S82.56XB Nondisp fx of med malleolus of unsp tibia, 7thB
  • S82.66XB Nondisp fx of lateral malleolus of unsp fibula, 7thB
  • S82.843B Displ bimalleol fx unsp lower leg, init for opn fx type I/2
  • S82.899B Oth fracture of unsp lower leg, init for opn fx type I/2

SNOMED

  • 263091001 Fracture dislocation of ankle joint (disorder)
  • 16114001 Fracture of ankle (disorder)
  • 209349006 Closed fracture dislocation, ankle joint (disorder)
  • 209350006 Open fracture dislocation, ankle joint (disorder)
  • 281531008 Fracture of medial malleolus (disorder)
  • 281535004 Fracture of lateral malleolus (disorder)