Ankle

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    Ankle Fractures

    Stable Vs. Unstable

    • The key is to determine if the injury is stable (non-operative mgmt) vs unstable (operative management).  To help in determining this, the most common is the closed ring classification system.
    • Physiologically plantarflexed ankle is unstable compared to dorsiflexed becaused talus makes larger contact with tibia when dorsiflexed.
    • Closed ring classification system of ankle fractures
      • The ankle of thought of as a ring of bone and ligaments surrounding the talus
      • ankleClassification.jpg
      • Composed of:
        • Tibia
        • Tibiofibular ligament (syndesmosis)
        • Fibula
        • Lateral ankle ligaments (anterior talofibular ligament, posterior talofibular ligament, calcaneofibular ligament.)
        • Calcaneus
        • Deltoid ligament
      • AnkleAnatomy.JPG
      • Key concept:
          • Stable Injury: A single disruption of the ring whether osseous or ligamentous, results in a stable injury
          • Unstable injury: Ring disruption in two places.
            • Can involve two bones (i.e. bimalleolar #) or ligament+bone (lateral malleolus and deltoid ligament rupture)
      •  
      • NOTES:
        • When fracture/displacement is present, clinician should suspect occult ligamentous disruption.
        • On exam: Palpate the entire length of the fibula (Maisonneuve injury can involve proximal fibular fracture).
        • On exam: pay special attention for medial tenderness, and suspect medial malleolus # or deltoid ligament tear.  If present pay special attention on xrays.  If cannot see medial damage on xrays and no lateral talar shift: can presumptively treat as unstable or hang foot off the pillow with medial side up and xray to see if shifted (special xray technique).
        • The best criterion for assessing deltoid ligament rupture is lateral talar shift.  This is when space bwn medial malleolus and talus is greater than space btwn talar dome and tibial plafond. (aka bimalleolar equivalent fracture). 
        • xrayAnkle.JPG
    • Some Terms
      • Bimalleolar fracture: lateral and medial malleolus fracture
      • Trimalleolar fracture: lateral, medial, and posterior malleolus fracture.
      • Maisonneuve fracture: if fibula fractured proximally in combination with medial malleolus # (or deltoid ligament) and disruption of the talofibular syndesmosis.
    • Treatment
      • Ankle is considered stable when talus moves in a normal pattern during ROM.  If talar movement is abnormal, then articular cartilage is damaged, degenerates, and leads to premature arthritis.  Ankle stability is the most important factor.  Unstable injuries require operative fixation.
      • Primary stabilizer of the ankle are medial structures.
      • A fracture of the fibula does not result in abnormal talar movement as long as the medial structures are intact.  (many studies corroborated this - can be managed by closed methods.  If medial malleolus is involved, only 65% pts with closed management had satisfactory results compared to 90% in surgical pts).
      • Usually require a posterior slab with a U-shaped stirrup.
      • Stable Injuries:
        • Require no reduction and have an excellent prognosis.
        • Examples: distal fibular fractures (common), and some isolated distal medial malleolus fractures.
        • Initially treat with:
          • Posterior splint
          • Crutches
          • Elevation
          • Ice until swelling goes down.
        • Definitive management for isolated distal fibular fractures include short leg walking cast or cast book x4-6weeks.  The goal is protection from further injury (can even use high tennis shoe).
        • Medial malleolus: most treated operatively, but can be non-operatively if distal and minimally displaced.
      • Unstable Injuries:
        • Should undergo closed reduction and splinting in ED.
        • Definitive mgmt is surgery, but good reduction in ED prevents further injury to articular cartilage, and allows swelling to resolve faster, and prevent skin ischemia.
        • Reduction:
          • Analgesia
          • Apply gentle traction and gradual motion to move talus back to reduced position.  
          • Splint ankle immediately to maintain reduction.  (used posterior U splint)
          • Post-reduction films to confirm.
          • If cannot reduce, urgent operative intervention is necessary.
      • Fracture Dislocations
        • Can be lateral (most common), posterior, anterior, or superior
        • ALWAYS check for vascular integrity
          • If vascular compromise, reduce immediately
        • Open fracture dislocations are only reduced in ED if there is vascular compromise (need procedural sedation).
        • Reduction technique  (always have knee at 90% to relax soleus/gastroc, and generally reduced plantarflexion b/c disengages the talus).
          • Lateral Dislocation: simple: axial traction with hand on heel and one hand on foot dorsum, while assistant provides countertraction at the knee.  Next rotate the foot into position until hear a "thud".
          • Posterior Dislocation: one hand on shin, other hand on heel, with axial traction pull foot into position (while plantarflexed).
          • Anterior DislocationI: Opposite of posterior.  Reduce dorsiflexed.
          • Superior: Serious injuries, consult ortho.
      • Tibial Plafond Fractures
        • High energy axial compression is common mechanism.
        • Part of the tibia breaks depends on the position of foot when injury happens b/c talus puts pressure on tibia and fractures it (i.e if dorsiflexed - anterior).
        • Require ice, elevation, immobilization, and emergent referral for ORIF.

    Ankle Sprains

    • 75% of all ankle injuries
    • Most common to least:
      • lateral ligaments (vast majority)
      • tibiofibular syndesmotic 
      • medial ligaments
    • Typically result in forced inversion/eversion injuries while ankle is plantarflexed.

    Sequence of Structures Injured with Inversion and Eversion Ankle Sprains

    Inversion Stress 

    Eversion Stress 

    Anterior talofibular ligament

    Medial malleolus avulses (deltoid ligament rupture)

    Calcaneofibular ligament

    Anterior-inferior tibiofibular ligament

    Posterior talofibular ligament

    Interosseous (syndesmotic) ligament

    • Physical Exam:
      • Check for swelling/tenderness over the ATFL, CFL
      • Stress joints (distinguish 2nd and 3rd deg tear).
        • Anterior drawer test: first test - examines for rupture of ATFL.  (One hand on tibia, the other on heel.   Pull up on heel  - test for laxity).
          •  If negative, no need to do inversion test b/c requires ATFL and CFL rupture to be positive.
        • Inversion test (talar tilt test) - exams CFL rupture.  Often painful, not recommended to perform.  (5-10% difference btwn ankles is positive).
        • Squeeze test - tests for syndesmotic ligament sprain.

     

     

    • Rate ankle injuries based on degree of sprain
      • First Degree - Stretching of ligament fibres without tear.
        • Usually no functional loss, often do not seek care, usually treat themselves at home.  Minimal or no ankle swelling, mild tenderness on stressing the joint in direction of force.
        • Treatment:  (RICE - rest, ice, compress, elevate)
          • 1.  Ice packs (crush, put in thin cloth to avoid skin injury) recommended 20min 4-6x/day for first 2 days
          • 2.  Elevation (facilitate venous + lymphatic drainage)
          • 3.  Elastic bandage (from base of toes to mid-calf)
          • 4.  Early mobilization (can start immediately, wt bearing as tolerated)
          • 5.  NSAIDs for analgesia (may improve outcome)
          • Back to normal in 1 week.
      • Second Degree - Partially torn ligament
        • Anywhere from a few fibres torn to complete tear with just a few fibres remaining.
        • Pts present with modern swelling, complain of immediate pain on ankle stress.  (first degree often have pain next day or later).
        • Need to stress the joint to distinguish btwn 2nd and 3rd deg injury - pain acutely does not allow stress testing, may need to immobilize, no wt bearing and serial examinations.
        • Complications: ligamentous laxity, recurrent sprains due to instability
        • Treatment
          • 1.  SAME AS 1ST DEGREE 
          • 2.  ROM only exercises on day 1
          • 3.  Keep from weight bearing 48-72hrs, then touchdown wt bearing w crutches ASAP.
          • 4.  Encouraged to use ankle support for initial wt bearing (lace-up braces, semi-rigid bimalleolar orthotics, and air splints). 
          • 5.  Once comfortable, strengthen plantar/dorsiflexors.
          • 6.  Follow-up with orthopedics/sports med recommended.
      • Third Degree - Complete tear
        • Egg shaped swelling over lateral ligaments in two hours.
        • Hard to distinguish severe 2nd and 3rd degree tear - need to really stress the joint.  
        • Examination 5 days post-injury better at distinguishing 2nd and 3rd degree.  (can stress joint).
        • Treatment:
          • Immobilization with splint for 72hrs + ice + elevation
          • Referral
          • Treatment controversial b/c significant talar instability may occur.  Can graft tendon if significant instability and young pt.

    Sinus Tarsi Syndrome

    • Sinus tarsi are spaces on lateral foot between talus and calcaneus.  These ligaments often injuried after inversion injury (chronic pain and instability).
    • Classically: pain when walking on uneven ground relieved by rest.
    • Dx: can inject local anesthetic into the space laterally, which will relieve the pain.
    • Mgmt:
      • NSAIDs
      • Orthotics.
      • Local anesthetic and steroid injections into sinus tarsi
      • Surgery last resort.

     

    Talar Dome Osteochondral Injury

    • Osteochondritis dessicans (OCD): when fracture through cartilage and underlying bone causes tissue death + resorption (causes pain).  Sometimes fragments can dislodge causing arthritis.
    • A fragment of bone at the osteochondral junction dislodges and enters the joint causing arthritis. 
    • Pts come in with traumatic arthritis following ankle injury.  
    • Classically pain with activity, relieved by rest.
    • Can be detected on xrays (AP w dorsiflexion), but CT and MRI are better.
    • Tx: Need arthroscopy + debridement.  if delayed >1yr outcome is poor.

     

    Talotibial Exostosis

    • Tibial outgrowth (multiple areas)
    • Often in athletes with repetitive trauma.
    • Convervative tx, if bothers then arthroscopic debridement.

     

    Peroneal Tendon Dislocation

    • Tendons that go around the lateral aspect of fibula dislodge.
    • Distinguish from ankle sprain (pain behind the lateral malleolus)
    • Sudden forceful contraction of peroneal muscles can cause this.
    • Put in posterior splint with compression over the lateral malleolus to stabilize the tendons.  
    • Conservative vs. surgical debated.  (in one study 74% of pts txed conservative returned to surgery later)
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