Ankle Fractures

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Introduction
  • Injury patterns
    • isolated medial malleolus fracture
    • isolated lateral malleolus fracture
    • bimalleolar and bimalleolar-equivalent fractures
    • posterior malleolus fractures
    • Bosworth fracture-dislocations
    • open ankle fractures
    • associated syndesmotic injuries
      • isolated syndesmosis injury 
Anatomy
  • Biomechanics
    • deltoid ligament (deep portion)
      • primary restraint to anterolateral talar displacement
    • fibula
      • acts as buttress to prevent lateral displacement of talus
Imaging
  • Radiographs
    • external rotation stress radiograph
      • most appropriate stress radiograph to assess competency of deltoid ligament
        • a medial clear space of >5mm with external rotation stress applied to a dorsiflexed ankle is predictive of deep deltoid disruption
      • more sensitive to injury than medial tenderness, ecchymosis, or edema
      • gravity stress radiograph is equivalent to manual stress radiograph
      • syndesmosis
        • decreased tibiofibular overlap 
          • normal >6 mm on AP view
          • normal >1 mm on mortise view
        • increased medial clear space 
          • normal less than or equal to 4 mm
        • increased tibiofibular clear space 
          • normal <6 mm on both AP and mortise views
    • radiographic measurements 
      • talocrural angle     
        • measured by bisection of line through tibial anatomical axis and another line through the tips of the malleoli
        • shortening of lateral malleoli fractures can lead to increased talocrural angle 
        • talocrural angle is not 100% reliable for estimating restoration of fibular length
          • can also utilize the realignment of the medial fibular prominence with the tibiotalar joint
Classification
  • Lauge-Hansen
    • based on foot position and force of applied stress/force
    • has been shown to predict the observed (via MRI) ligamentous injury in less than 50% of operatively treated fractures
Lauge-Hansen Class
Sequence
Supination - Adduction (SA)

  1. Talofibular sprain or distal fibular avulsion
  2. Vertical medial malleolus and impaction of anteromedial distal tibia
Supination - External Rotation (SER)

  1. Anterior tibiofibular ligament sprain
  2. Lateral short oblique fibula fracture (anteroinferior to posterosuperior)
  3. Posterior tibiofibular ligament rupture or avulsion of posterior malleolus
  4. Medial malleolus transverse fracture or disruption of deltoid ligament 
Pronation - Abduction (PA)
  1. Medial malleolus transverse fracture or disruption of deltoid ligament
  2. Anterior tibiofibular ligament sprain
  3. Transverse comminuted fracture of the fibula above the level of the syndesmosis
Pronation - External Rotation (PER)
    
  1. Medial malleolus transverse fracture or disruption of deltoid ligament 
  2. Anterior tibiofibular ligament disruption
  3. Lateral short oblique or spiral fracture of fibula (anterosuperior to posteroinferior) above the level of the joint
  4. Posterior tibiofibular ligament rupture or avulsion of posterior malleolus 

  • Anatomic / Descriptive 
    • isolated medial malleolar
    • isolated lateral malleolar
    • bimalleolar
    • trimalleolar
    • Bosworth fracture-dislocation (posterior dislocation of the fibula behind incisura fibularis)
  • Danis-Weber (location of fibular fracture)
    • A - infrasyndesmotic (generally not associated with ankle instability)
    • B - transsyndesmotic
    • C - suprasyndesmotic
  • AO / ATA
    • 44A - infrasyndesmotic
    • 44B - transsyndesmotic
    • 44C - suprasyndesmotic
General Treatment
  • Nonoperative
    • short-leg walking cast/boot
      • indications
        • isolated nondisplaced medial malleolus fracture or tip avulsions
        • isolated lateral malleolus fracture with < 3mm displacement and no talar shift
        • posterior malleolar fracture with < 25% joint involvement or < 2mm step-off
  • Operative
    • open reduction internal fixation
      • indications
        • any talar displacement 
        • displaced isolated medial malleolar fracture
        • displaced isolated lateral malleolar fracture
        • bimalleolar fracture and bimalleolar-equivalent fracture
        • posterior malleolar fracture with > 25% or > 2mm step-off q
        • Bosworth fracture-dislocations
        • open fractures
      • technique
        • goal of treatment is stable anatomic reduction of talus in the ankle mortise
          • 1 mm shift of talus leads to 42% decrease in tibiotalar contact area
        • see fracture patterns below for specific treatment
      • outcomes
        • overall success rate of 90%
          • prolonged recovery expected (2 years to obtain final functional result)
        • significant functional impairment often noted
        • worse outcomes with: smoking, decreased education, alcohol use, increased age, presence of medial malleolar fracture
        • ORIF superior to closed treatment of bimalleolar fractures
        • in Lauge-Hansen supination-adduction fractures, restoration of marginal impaction of the anteromedial tibial plafond leads to optimal functional results after surgery 
      • postoperative rehabilitation
        • time for proper braking response time (driving) returns to baseline at nine weeks for operatively treated ankle fractures  
        • braking travel time is significantly increased until 6 weeks after initiation of weight bearing in both long bone and periarticular fractures of the lower extremity  q
Isolated Medial Malleolus Fracture
  • Nonoperative
    • short leg walking cast or cast boot
      • indications
        • nondisplaced fracture and tip avulsions
          • deep deltoid inserts on posterior colliculus
          • symptomatic treatment often appropriate
  • Operative
    • ORIF
      • indications
        • any displacement or talar shift
      • technique
        • lag screw fixation
          • lag screw fixation stronger if placed perpendicular to fracture line
        • antiglide plate with lag screw 
          • best for vertical shear fractures   
        • tension band fixation 
          • utilizing stainless steel wire
Isolated Lateral Malleolus Fracture
  • Nonoperative
    • short leg walking cast vs cast boot
      • indications 
        • if intact mortise, no talar shift, and < 3mm displacement
        • classically fractures with more than 4-5 mm of medial clear space widening on stress radiographs have been considered unstable and need to be treated surgically
          • recent studies have shown the deep deltoid may be intact with up to 8-10 mm of widening on stress radiographs
          • if the mortise is well reduced, results from operative and non-operative treatment are similar 
  • Operative
    • ORIF
      • indications
        • if talar shift or > 3 mm of displacement
        • can be treated operatively if also treating an ipsilateral syndesmosis injury
      • technique
        • open reduction and plating q
          • plate placement
            • lateral
              • lag screw fixation with neutralization plating
              • bridge plate technique
            • posterior
              • antiglide technique
              • lag screw fixation with neutralization plating
              • most common disadvantage of using posterior antiglide plating is peroneal irritation if the plate is placed too distally  
            • posterior antiglide plating is biomechanically superior to lateral plate placement
        • intramedullary retrograde screw placement
        • isolated lag screw fixation
          • possible if fibula is a spiral pattern and screws can be placed at least 1 cm apart
      • post-operative care
        • period of immobilization usually 4-6 weeks after ORIF
        • duration of immobilization should be doubled in Diabetic patients 
 Medial and Lateral (Bimalleolar) Fracture
  • Nonoperative
    • total contact casting
      • indications
        • elderly or unable to undergo surgical intervention
  • Operative
    • ORIF
      • indications
        • any lateral talar shift
      • technique
        • fibula
          • need to fix with one of the options listed in section above
        • medial malleolus
          • fixation options
            • cancellous lag screws
            • bicortical screws 
            • tension band wiring
            • antiglide plate to treat a vertical medial malleolus fracture q
          • orient screws parallel to joint for vertical medial malleolar fracture (Lauge-Hansen supination-adduction fracture pattern) q   
 Functional Bimalleolar Fracture (deltoid ligament tear with fibular fracture)
  • Operative
    • ORIF of lateral malleolus
      • indications
        • examination has been shown to be largely unreliable in predicting medial injury
        • can see significant lateral translation of the talus in this pattern
      • technique
        • not necessary to repair medial deltoid ligament
        • only need to explore medially if you are unable to reduce the mortise
        • see isolated fibular fracture techniques above
Posterior Malleolar Fracture
  • Nonoperative
    • short leg walking cast vs cast boot
      • indications
        • < 25% of articular surface involved
          • evaluation of percentage should be done with CT, as plain radiology is unreliable
        • < 2 mm articular stepoff
        • syndesmotic stability
  • Operative
    • ORIF
      • indications
        • > 25% of articular surface involved
        • > 2 mm articular stepoff
        • syndesmosis injury
      • technique
        • approach
          • posterolateral approach  
          • posteromedial approach 
          • decision of approach will depend on fracture lines and need for fibular fixation
        • fixation
          • anterior to posterior lag screws to capture fragment (if nondisplaced)
          • posterior to anterior lag screw and buttress plate
          • antiglide plate
        • syndesmosis injury
          • stiffness of syndesmosis restored to 70% normal with isolated fixation of posterior malleolus (versus 40% with isolated syndesmosis fixation)
          • stress examination of syndesmosis still required after posterior malleolar fixation
          • posteroinferior tibiofibular ligament may remain attached to posterior malleolus and syndesmotic stability may be restored with isolated posterior malleolar fixation 
Bosworth Fracture-Dislocation
  • Overview
    • rare fracture-dislocation of the ankle where the fibula becomes entrapped behind the tibia and becomes irreducible
    • posterolateral ridge of the distal tibia hinders reduction of the fibula 
  • Operative
    • open reduction and fixation of the fibula in the incisura fibularis
      • indicated in most cases
Open Ankle Fracture
  • Operative
    • emergent operative debridement and ORIF
      • indicated if soft tissue conditions allow
      • primary closure at the index procedure can be performed in appropriately-selected Gustilo-Anderson grade I, II, and IIIA open fractures in otherwise healthy patients sustaining low-energy injuries without gross contamination 
    • external fixation
      • indications
        • soft tissue conditions and overall patient characteristics 
Associated Syndesmotic Injury
  • Overview
    • suspect injury in all ankle fractures 
      • most common in Weber C fracture patterns
      • fixation usually not required when fibula fracture within 4.5 cm of plafond
      • up to 25% of tibial shaft fractures will have ankle injury
  • Evaluation
    • measure clear space 1 cm above joint 
      • it has also been reported that there is no actual correlation between syndesmotic injury and tibiofibular clear space or overlap measurements
      • lateral stress radiograph has more interobserver reliability than an AP/mortise stress film
    • best option is to assess stability intraoperatively with abduction/external rotation stress of dorsiflexed foot
    • instability of the syndesmosis is greatest in the anterior-posterior direction
  • Treatment
    • operative
      • syndesmotic screw fixation
        • indications
          • widening of medial clear space  
          • tibiofibular clear space (AP) greater than 5 mm 
          • tibiofibular overlap (mortise) narrowed
          • any postoperative malalignment or widening should be treated with open debridement, reduction, and fixation  
        • technique
          • length and rotation of fibula must be accurately restored 
          • outcomes are strongly correlated with anatomic reduction 
            • placing reduction clamp on midmedial ridge and the fibular ridge at the level of the syndesmosis willa chieve most reliable anatomic reduction
          • "Dime sign"/Shentons line to determine length of fibula   
          • open reduction required if closed reduction unsuccessful or questionable
          • one or two cortical screw(s) 2-4 cm above joint, angled posterior to anterior 20-30 degrees
          • lag technique not desired
          • maximum dorsiflexion of ankle not required during screw placement (can't overtighten a properly reduced syndesmosis)
        • postoperative
          • screws should be maintained in place for at least 8-12 weeks
          • must remain non-weight bearing, as screws are not biomechanically strong enough to withstand forces of ambulation
        • controversies
          • number of screws
            • 1 or 2 most commonly reported
          • number of cortices
            • 3 or 4 most commonly reported
          • size of screws
            • 3.5 mm or 4.5 mm screws
          • implant material (stainless steel screws, titanium screws, suture, bioabsorbable materials)
          • need for hardware removal
            • no difference in outcomes seen with hardware maintenance (breakage or loosening) or removal at 1 year
            • outcome may be worse with maintenance of intact screws
Diabetic Ankle Fractures (with or without Neuropathy)
  • Risks
    • prolonged healing
    • high risk of hardware failure
    • high risk of infection
  • Enhanced fixation   
    • multiple quadricortical syndesmotic screws (even in the absence of syndesmotic injury)
    • tibiotalar Steinmann pins or hindfoot nailing
    • ankle spanning external fixation
    • augment with intramedullary fibula K-wires
    • stiffer, more rigid fibular plates (instead of 1/3 tubular plates)
      • compression plates
      • small fragment locking plates
  • Delay weightbearing   
    • maintain non-weightbearing postop for 8-12 weeks (instead of 4-8 weeks in normal patients
Complications 
  • Wound problems (4-5%)
  • Deep infections (1-2%)
    • up to 20% in diabetic patients
      • largest risk factor for diabetic patients is presence of peripheral neuropathy  
  • Post-traumatic arthritis 
    • rare with anatomic reduction and fixation
    • corrective osteotomy requires anatomic fibular and mortise correction for optimal outcomes   
 

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Questions (30)

(OBQ13.54) Figure A shows an isolated left ankle injury in an active 48-year-old recreational hockey player. Past medical history includes insulin dependent diabetes mellitus for 35 years. On physical examination the patient is unable to feel a 5.07 gm monofilament on the plantar aspect of his foot. His pedal pulses are palpable. Of the following options, what would be the recommended treatment? Review Topic

QID:4689
FIGURES:
1

Closed reduction and casting for 6 weeks

1%

(16/2967)

2

Closed reduction and casting for 12 weeks

1%

(36/2967)

3

Open reduction and internal fixation with restricted weight bearing for 2 weeks

2%

(61/2967)

4

Open reduction and internal fixation with restricted weight bearing for 6 weeks

15%

(456/2967)

5

Open reduction and internal fixation with restricted weight bearing for 12 weeks

80%

(2383/2967)

Select Answer to see Preferred Response

PREFERRED RESPONSE 5

Figure A shows an unstable, ankle fracture-dislocation in a otherwise healthy 48-year-old diabetic patient. The most appropriate management would be open reduction and internal fixation with an extended period of restricted weight-bearing.

Surgical treatment of unstable ankle fractures in diabetic patients is associated with a high complication rates. Diabetic patients are inherently poor healers due to the alterations in their microvascular system. Over-fixation of the fracture and extended immobilization has been shown to reduce wound and bone healing complications associated with diabetes. Surgical techniques typically call for multiple syndesmotic screws, stronger plates (vs 1/3 tubular plates) and prolonged periods of immobilization.

Jani et al. retrospectively examined a cohort of 15 patients with diabetes mellitus who sustained unstable ankle fractures. The combination of transarticular fixation (Retrograde transcalcaneal-talar-tibial fixation using large Steinmann pins or screws) and prolonged (>12 weeks), protected weightbearing provided 13 of 15 patients with a stable ankle for weight bearing.

Wukich et al. compared the complication rates of ankle fracture fixation in 46 patients with complicated diabetes and 59 patients with uncomplicated diabetes. They found that patients with complicated diabetes had 3.4 times increased risk of a non-infectious complications (eg. malunion, nonunion or Charcot arthropathy) and 5 times higher likelihood of needing revision surgery/arthrodesis.

Figure A shows AP and lat radiographs of SER4 ankle fracture-dislocation.

Incorrect Answers:
Answer 1,2: Non-operative treatment would be appropriate in stable ankle fractures. Again, these need to be treated with an extended period of immobilization.
Answer 3,4: Internal fixation would be warranted in this patient, however the duration of immobilization should more than double the typical period of immobilization.


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(OBQ13.261) A 27-year-old man presents to the emergency department with an ankle fracture. CT scans note anteromedial marginal impaction. Which radiograph (Figures A-E) would best correlate with this finding? Review Topic

QID:4896
FIGURES:
1

Figure A

5%

(117/2202)

2

Figure B

5%

(113/2202)

3

Figure C

2%

(37/2202)

4

Figure D

86%

(1890/2202)

5

Figure E

2%

(37/2202)

Select Answer to see Preferred Response

PREFERRED RESPONSE 4

This patient has anteromedial marginal impaction seen on CT scans. This is characteristic of a supination-adduction ankle fracture (Figure D).

In the Lauge-Hansen classification, ankle fractures are classified into supination-adduction (SA), supination-external rotation, pronation-abduction, pronation-external rotation. Certain considerations exist when treating SA fractures with marginal impaction: (1) An anteromedial approach will aid in visualizing and reducing the impaction (instead of standard medial approach). (2) Disimpaction of the articular fragment and possibly bone grafting of the resulting defect may be necessary rather than simple percutaneous fixation.

McConnell et al. reviewed marginal plafond impaction in supination adduction injuries. Supination-adduction injuries comprised 5% of 500 fractures (44 fractures), and 42% (8 fractures) of these had marginal impaction.

Illustration A is another example of a SA fracture depicting vertical fracture of the medial malleolus in association with marginal impaction of the plafond (arrow). Illustration B is an axial CT showing increased density at the level of the subchondral bone, characteristic of anteromedial marginal impaction. Illustration C is a coronal CT showing showing articular depression of the impacted segment and tibiotalar incongruity.

Incorrect Answers:
Answer 1: Figure A shows a pronation-abduction ankle fracture.
Answer 2: Figure B shows a talar body fracture.
Answer 3: Figure C shows a pronation-external rotation ankle fracture
Answer 5: Figure E shows a supination-external rotation ankle fracture.
Marginal impaction is not characteristic of these injuries.

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(OBQ12.127) A 34-year-old female requests a second opinion following open reduction internal fixation (ORIF) of her left ankle three weeks ago. Which of the following is most appropriate step based on Figures A and B? Review Topic

QID:4487
FIGURES:
1

Progressive weightbearing in 3-4 weeks based on radiographs

2%

(78/3777)

2

Deltoid ligament repair vs reconstruction

8%

(319/3777)

3

Revision ORIF of fibula with lengthening

10%

(393/3777)

4

Revision ORIF of fibula and syndesmosis

76%

(2864/3777)

5

Removal of syndesmotic screws in 3-6 months

3%

(98/3777)

Select Answer to see Preferred Response

PREFERRED RESPONSE 4

The above clinical scenario shows acute postoperative fibular malrotation and tibiofibular syndesmotic malreduction. Restoration of the proper syndesmotic relationship involves regaining fibular length as well as reestablishing correct rotation and position of the fibula relative to the tibia. In addition, removal of interposed tissue (deltoid ligament) in the medial joint space may be necessary. However, deltoid reconstruction is not routinely required.

Syndesmosis screw fixation in ankle fractures with syndesmotic disruption is indicated if there is residual or dynamic instability with stress testing of the tibiofibular joint after fixation of the fibula. Syndesmotic screws are commonly maintained in place for at least 12 weeks before removal, if necessary or desired. Controversy exists over use of 1 or 2 screws, screw size, and purchase of 3 or 4 cortices.

Gardner et al. compared radiographic measurements vs CT scans to assess reduction of the tibiofibular syndesmosis in ankle fractures. They found CT was better able to detect syndesmotic malreduction. Although they did not seek to correlate this with functional outcomes, they recommended heightened vigilance for assessing accurate syndesmosis reduction.

Zalavras et al. performed a review on ankle syndesmotic injuries. In their review, they highlight that syndesmotic injuries may occur in isolation or may be associated with ankle fractures. In the absence of fracture, physical examination findings suggestive of injury include ankle tenderness over the anterior aspect of the syndesmosis and a positive squeeze or external rotation test. They recommend stress testing for detecting syndesmotic instability with fixation of the syndesmosis when evidence of a diastasis is present.

Figures A and B show an ankle fracture treated with ORIF and syndesmotic repair, with syndesmotic and fibular malreduction.

Incorrect Answers:
Answer 1&5: Would not address the current syndesmotic malreduction which should be addressed.
Answer 2: Would not address the syndesmotic malreduction.
Answer 3: Fibular length appears appropriate on AP and lateral radiographs.


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(OBQ11.17) A 25-year-old male sustains an ankle fracture dislocation and undergoes open reduction and internal fixation. He returns to clinic five months following surgery complaining of continued ankle pain and instability with weight bearing. His immediate post-operative AP radiograph is seen in Figure A. Which of the following could have prevented this patient from developing persistent pain? Review Topic

QID:3440
FIGURES:
1

Deep deltoid ligament repair

1%

(32/2967)

2

Quadricortical syndesmotic screw fixation

2%

(74/2967)

3

Restoration of fibular length and rotation

93%

(2770/2967)

4

Lateral collateral ligament complex repair

0%

(6/2967)

5

Use of two syndesmotic screws

2%

(62/2967)

Select Answer to see Preferred Response

PREFERRED RESPONSE 3

The patient presents with continued ankle pain and instability following open reduction and internal fixation. The radiograph in figure A demonstrates inadequate restoration of fibular length, likely leading to continued tibiotalar instability.

Illustration A demonstrates fibular malreduction with dislocation of the fibula anterior to the tibial incisura. Illustration B shows a comminuted fibula fracture along with a measurement of length from an intact fibula. The arc from the lateral process of the talus to the peroneal groove of the distal fibula is known as the "dime" sign and should remain unbroken if fibular length has been restored. Illustration C demonstrates the use of a push-pull screw and lamina spreader to regain length intraoperatively for a comminuted fibula fracture.

Chu and Weiner review management of malunions of the distal fibula. The authors state that restoration of fibular length, alignment and rotation leads to reduction of the talus, provides a buttress to talar motion in the setting of an incompetent deltoid, and allows the syndesmotic ligaments to heal at the appropriate tension.

Wikeroy et al conducted a study of patients from a prior prospective, randomized control trial comparing different methods of syndesmotic fixation. There was no significant difference in outcomes between tricortical or quadricortical 3.5mm screw fixation, however worse outcomes were seen with associated posterior malleolar fractures, obesity, a difference in sydesmotic width of 1.5mm or greater, and a CT confirmed tibio-fibular synostosis.

Sinha et al present a simple technique for fibular lengthening in the setting of distal fibula malunion. They found high union rates and improved AOFAS scores at short-term follow up with their technique.

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(OBQ10.5) A 32-year-old female sustains the injury shown in Figure A. What is the most reliable method to evaluate the competence of the deltoid ligament? Review Topic

QID:3093
FIGURES:
1

Medial ankle tenderness

3%

(37/1133)

2

Medial ankle ecchymosis

1%

(7/1133)

3

Squeeze test

1%

(7/1133)

4

Stress radiography of the ankle

95%

(1075/1133)

5

Canale view radiograph

0%

(3/1133)

Select Answer to see Preferred Response

PREFERRED RESPONSE 4

Figure A shows a lateral malleolar fracture from a rotational-type injury. Evaluation of the medial structures (deltoid ligament) is important for therapeutic reasons, as medial sided instability will portend a poor prognosis if treated nonoperatively.

The referenced study by McConnell et al showed that physical exam is a poor indicator of medial ankle injury and that stress radiography is needed for proper medial ankle evaluation. All ankles found to be stable via stress examination healed with an intact mortise.

The study by Gill et al showed that gravity stress radiographs are equivalent to manual stress radiographs of the ankle when evaluating rotational ankle fractures. This was true when both pronation-external rotation and supination-external rotation ankle fractures were examined.

Illustration A shows the proper way to obtain a gravity stress radiograph.

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(OBQ10.40) In an isolated ankle syndesmotic injury, the fibula is unstable in the incisura fibularis of the tibia. In what direction is the fibula most unstable? Review Topic

QID:3128
1

Anterior-posterior

48%

(369/763)

2

Medial-lateral

25%

(194/763)

3

Proximal-distal

2%

(14/763)

4

Rotational

22%

(166/763)

5

Equivalent instability in all axes

2%

(13/763)

Select Answer to see Preferred Response

PREFERRED RESPONSE 1

In an ankle syndesmosis injury, the fibula is most unstable in an anterior and posterior direction. This is whether or not there is an accompanying ankle fracture. Most commonly, the fibula will subluxate in an anterior-posterior direction in an ankle fracture model.

The first referenced article by Xenos et al found that stress lateral radiographs have more interobserver reliability than stress AP/mortise radiographs and that two syndesmotic screws are stronger than one.

The referenced article by Candal-Couto et al is a biomechanical study that found more anterior-posterior instability in a syndesmosis injury model, and more ankle instability is noted with syndesmosis injury and a concomitant deltoid injury.

The referenced article by Zalavras et al is an excellent review article on ankle syndesmosis injuries.


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(OBQ10.121) A 34-year-old man sustains a twisting injury to his left ankle playing soccer. Radiographs from the ER are provided in figures A and B. Four hours later, he undergoes open reduction internal fixation. An intraoperative fluoroscopy image is provided in figure C. Which of the following is the best method to assess the integrity of the syndesmosis? Review Topic

QID:3215
FIGURES:
1

Measurement of medial clear space widening

5%

(20/436)

2

Measurement of the tibiofibular overlap

5%

(22/436)

3

Anterior drawer test with comparison to the contralateral ankle

2%

(7/436)

4

External rotation stress radiograph

87%

(380/436)

5

Evaluation of the syndesmosis on preoperative CT scan

1%

(4/436)

Select Answer to see Preferred Response

PREFERRED RESPONSE 4

The radiograph demonstrates a Weber B ankle fracture. A dynamic external rotation stress test with the ankle dorsiflexed to 90 degrees is the most accurate way to evaluate the integrity of the syndesmosis.

Nielson et al evaluated 70 ankle fractures with radiographs and MRI. Neither measurements of the tibiofibular clear space nor the tibiofibular overlap correlated with syndesmotic injury on MRI. Medial clear space widening of more than 4 mm occurred with MRI evidence of disruption of the deltoid and the tibiofibular ligaments.

Nielson et al used this same cohort of ankle fractures in a separate study to evaluate whether the level of the fibular fracture correlated with syndesmotic incompetence. They found no correlation. The level of fracture on the fibula cannot be used to accurately predict disruption of the syndesmosis.

Ebraheim et al reviewed a series of Weber B fibula fractures with deltoid injury and syndesmotic disruption. Their findings concluded that the surgeon's dynamic assessment of syndesmotic stability was more predictive of syndesmotic stability than any imaging parameters including radiographs and CT scans.


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(OBQ09.17) A 34-year-old male falls off of a ladder and sustains the ankle injury shown in Figure. Which of the following is unique with this particular ankle fracture pattern and must be recognized by the operating surgeon to optimize outcomes? Review Topic

QID:2830
FIGURES:
1

Marginal impaction of the anteromedial tibial plafond

74%

(1295/1758)

2

Syndesmosis diastasis

7%

(122/1758)

3

Deltoid ligament tear

2%

(38/1758)

4

Posterolateral osteochondral lesion of the talus

16%

(274/1758)

5

Fibular overlengthening

1%

(25/1758)

Select Answer to see Preferred Response

PREFERRED RESPONSE 1

The radiograph demonstrates a Lauge-Hansen supination-adduction fracture-dislocation. There is a transverse fibula fracture and a vertical medial malleolus fracture.

McConnell and Tornetta performed a Level 4 review and found that nearly 50% of these injuries have marginal impaction of the anteromedial tibial plafond and they found that anatomic reduction of that aspect of the injury led to good to excellent outcomes.


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(OBQ09.52) In which of the following radiographs of different types of ankle fractures should the medial malleolus be treated with screw fixation directed parallel to the ankle joint? Review Topic

QID:2865
FIGURES:
1

Figure A

88%

(410/467)

2

Figure B

5%

(22/467)

3

Figure C

2%

(11/467)

4

Figure D

2%

(11/467)

5

Figure E

2%

(9/467)

Select Answer to see Preferred Response

PREFERRED RESPONSE 1

Figure A show a classic SAD (supination adduction) fracture according to the Lauge-Hansen Classfication. This is evident by the vertical medial malleolar fracture and supinated position of the foot. The vertical medial malleolar fracture is best treated by screw fixation parallel to the joint (perpendicular to the fracture line). Careful attention must be paid to the presence of any medial plafond impaction from the talar displacement; if this is present, disimpaction and stabilization must be performed in order to optimize outcomes.

The referenced review article by Michelson covers rotational ankle fractures, with a review of the diagnosis, treatment options, and patient outcomes. He notes that unstable fractures (bimalleolar, bimalleolar equivalent, etc.) usually are managed with open reduction and internal fixation for optimal outcomes.

Incorrect answers:
Figure B shows a Weber C (high fibular) ankle fracture, PER, without any evidence of a medial malleolar fracture.
Figures C (SER IV), D (PER IV), and E (isloated medial malleolar fracture) all show fractures not suitable for screw fixation of the medial malleolus parallel to the joint since their fracture lines are not vertical.


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(OBQ09.70) Following operative repair of lower extremity long bone and periarticular fractures, what is the time frame for patients to return to normal automobile braking time? Review Topic

QID:2883
1

6 weeks after initiation of weight bearing

76%

(194/254)

2

4 weeks postoperatively

1%

(2/254)

3

8 weeks from the date of injury

12%

(31/254)

4

Once full range of motion of the ankle and knee exist

8%

(21/254)

5

At the time of bony union

2%

(4/254)

Select Answer to see Preferred Response

PREFERRED RESPONSE 1

According to the first referenced study by Egol et al, appropriate braking time returns at a point 6 weeks after initiation of weightbearing after treatment of lower extremity long bone and periarticular fractures, as examined with a driving simulator. No differences were seen in return of braking time between periarticular fractures and long bone injuries.

The second reference by Egol studied only operatively treated ankle fractures and found that time to appropriate braking returns at 9 weeks postoperatively. Interestingly, no significant association was found between the functional scores and normalization of total braking time.


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(OBQ09.121) A 31-year-old male sustains an irreducible ankle fracture-dislocation with the foot maintained in an externally rotated position. An AP and lateral radiograph are shown in figures A and B respectively. The attempted post reduction AP and lateral are shown in C and D. What structure is most likely preventing reduction? Review Topic

QID:2934
FIGURES:
1

Anterior-inferior tibiofibular ligament

7%

(29/387)

2

Posterior-inferior tibiofibular ligament

3%

(13/387)

3

Peroneus brevis tendon

11%

(42/387)

4

Posterolateral ridge of the tibia

27%

(104/387)

5

Flexor hallucis longus tendon

51%

(198/387)

Select Answer to see Preferred Response

PREFERRED RESPONSE 4

As described by Hoblitzell et al, the so-called "Bosworth fracture-dislocation" is a rare fracture-dislocation of the ankle where the fibula becomes entrapped behind the tibia and becomes irreducible. It can cause compartment syndrome, as reported by Beekman and Watson.

Hoblitzell et al stress the importance and difficulty of recognizing these injuries. Standard radiographs are difficult to interpret due to the often severe external rotation of the foot. Prompt treatment, though can lead to good results in patients. The posterolateral ridge of the distal tibia hinders reduction and reduction often requires an open technique

Mayer and Evarts stated AP and mortise radiographs can be hard to interpret due to the external rotation posture of the foot. In their series a closed reduction consisting of traction and medial rotation applied to the foot while the fibular shaft is pushed laterally was successful in 3/4 patients.


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(OBQ09.173) In the Lauge-Hansen classification system, a pronation-abduction ankle fracture has what characteristic fibular fracture pattern? Review Topic

QID:2986
1

Transverse fracture below the level of the syndesmosis

14%

(128/937)

2

Short oblique fracture running from anteroinferior to posteriosuperior

9%

(88/937)

3

Short oblique fracture running from posteroinferior to anteriosuperior

4%

(38/937)

4

Comminuted fracture at or above the level of the syndesmosis

72%

(672/937)

5

Wagstaff fracture

1%

(6/937)

Select Answer to see Preferred Response

PREFERRED RESPONSE 4

In the Lauge-Hansen classification, the characteristic fibular fracture pattern in a pronation-abduction injury is a comminuted fibular fracture above the level of the syndesmosis. In the first stage of this injury pattern, the deltoid fails in tension, or an avulsion fracture of the medial malleolus occurs. In the second stage, the anterior inferior tibiofibular ligament ruptures, or a small bony avulsion of this ligament's insertion/origin occurs. The final stage includes the creation of a comminuted fibular fracture above the level of the syndesmosis.

The referenced article by Siegel et al noted that extraperiosteal bridge plating of these ankle injuries was safe and had excellent radiographic and clinical outcomes at final follow-up.


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(OBQ09.204) An 18-year-old football player presents to the emergency department after sustaining an ankle injury. His radiograph is shown in figure A. What is the most appropriate definitive treatment? Review Topic

QID:3017
FIGURES:
1

Open reduction and internal fixation of the medial malleolus with syndesmosis reduction and suture-button repair

1%

(6/420)

2

Repair of the anterior talo-fibular ligament

0%

(0/420)

3

Open reduction internal fixation of the fibula with syndesmosis reduction and suture-button repair

1%

(5/420)

4

Open reduction internal fixation of the medial malleolus and fibula

4%

(15/420)

5

Open reduction internal fixation of the fibula and medial malleolus with syndesmosis reduction and suture-button repair

94%

(393/420)

Select Answer to see Preferred Response

PREFERRED RESPONSE 5

The radiograph demonstrates an ankle fracture-dislocation. There is diastasis of the distal tibia and fibula, indicating a syndesmosis injury.

Zalavras et al stated failure to recognize and treat the syndesomsis injury leads to inferior outcomes, and should be assessed after fibula and medial malleolar fixation. Treatment of choice is reduction of the syndesmosis and fixation.


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(OBQ09.259) Presence of diabetes-induced peripheral neuropathy has been shown to be an independent risk factor for postoperative complications of which of the following injuries? Review Topic

QID:3072
1

Distal radius fractures

1%

(2/356)

2

Patella fractures

0%

(0/356)

3

Metatarsal fractures

12%

(41/356)

4

Ankle fractures

88%

(312/356)

5

Distal femoral fractures

0%

(1/356)

Select Answer to see Preferred Response

PREFERRED RESPONSE 4

Presence of peripheral neuropathy has important implications in treating ankle fractures in diabetic patients. Increased immobilization periods, attention to tight glucose control, and adjunct/alternative operative techniques may be necessary for an optimal outcome.

The first referenced article by Chaudry et al is an excellent review of diabetic ankle fractures.

The second reference by Costigan et al noted that peripheral neuropathy is the most significant risk factor for postoperative complications, followed closely by lack of pedal pulses preoperatively.

The last referenced article by Jones et al noted a significantly higher complication rate in diabetics with operative ankle fractures, and reported that neuroarthropathy is a significant risk factor for postoperative complications.


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(OBQ08.81) A 19-year-old male sustains the injury shown in Figure A while skiing. Injury to what structure should be evaluated intraoperatively during fixation of the fibula? Review Topic

QID:467
FIGURES:
1

Deltoid ligament

5%

(16/315)

2

Syndesmosis

92%

(291/315)

3

Proximal fibula

1%

(3/315)

4

Calcaneofibular ligament

1%

(2/315)

5

Posterior tibial tendon

0%

(1/315)

Select Answer to see Preferred Response

PREFERRED RESPONSE 2

According to the referenced study by Jenkinson et al, up to 37% of operatively treated ankle fractures can have undetected syndesmotic instability when examined intraoperatively. This is important due to the negative effects of a displaced mortise and the abnormal loading forces seen on the talus with even a 2mm lateral shift. Also, fibular fractures >4.5cm proximal to the mortise are more likely to be associated with syndesmotic instability, especially when deltoid ligament tears are present. When fixing the syndesmosis, Tornetta et al's referenced study has shown that the syndesmotic compression has no negative effects on ankle range of motion.


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(OBQ08.93) A 35-year-old male with a pronation abduction ankle injury would have which of the following radiographs? Review Topic

QID:479
FIGURES:
1

Figure A

7%

(111/1628)

2

Figure B

17%

(282/1628)

3

Figure C

5%

(76/1628)

4

Figure D

69%

(1122/1628)

5

Figure E

2%

(31/1628)

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PREFERRED RESPONSE 4

Figure D shows a pronation abduction ankle fracture according to the Lauge-Hansen classification. This injury pattern is associated with a comminuted fibula fracture above the level of the syndesmosis and frequently has a concominant syndesmotic injury.

Lauge-Hansen's classic article describes in detail his proposed classification of ankle fractures based on both the position of the foot (supination or pronation) and an externally applied deforming force (adduction, abduction, external rotation). The Lauge-Hansen classification system is based on cadaveric experiments using manually applied forces and roentographs performed at each stage of injury.

Edwards and DeLee review their results in managing diastasis of the tibiofibular joint without an associated fracture. The authors propose a classification system of this uncommon injury and and theorize that the injury results from a pronation abduction mechanism.

Incorrect Answers:
Answer 1: Figure A represents a supination adduction fracture based on the vertical medial malleolar fracture, medial dislocation on the talus, and low transverse fibula fracture.
Answer 2: Figure B represents a pronation external rotation injury; note the high oblique fibula fracture and corresponding transverse medial malleolus fracture.
Answer 3: Figure C represents a supination external rotation ankle injury based on the oblique fibula fracture at the level of syndesmosis and the associated transverse medial malleolar fracture.
Answer 4: Figure E represents a pilon fracture based on the significant articular comminution signifiying an axial loading mechanism instead of a rotational injury.


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(OBQ08.210) A 68-year-old female sustains a closed ankle fracture and is treated with open reduction and internal fixation. Her postoperative radiographs are shown in Figure A. Widening of the tibia-fibular clear space with external rotation stress would be a result of injury of which structure? Review Topic

QID:596
FIGURES:
1

Anterior ankle joint capsule

0%

(4/1644)

2

Syndesmosis

98%

(1610/1644)

3

Anterior talofibular ligament

2%

(25/1644)

4

Posterior tibial tendon

0%

(0/1644)

5

Calcaneofibular ligament

0%

(1/1644)

Select Answer to see Preferred Response

PREFERRED RESPONSE 2

The radiograph shows a trimalleolar ankle fracture, which can be associated with syndesmosis injuries. The syndesmosis acts to maintain the relationship of the fibula in the incisura fibularis of the distal tibia as well as the congruity of the ankle joint. Failure to detect these injuries can lead to lateral talar shift and negative outcomes. So, if there was an isolated fibula fracture, the stress examination would test the deep fibers of the deltoid ligament complex. However, in this case, with fixation of the fibula, widening of the ankle joint would require an injury to the syndesmosis, as this structure would prevent it after restoration of the lateral column of the ankle (fibula).

Beumer et al describe that stress radiographs may be performed by external rotation stress on the hindfoot or by providing a lateral "pull" on the distal fibula after fixation (Cotton test).

Park et al showed that "ankle stress radiographs taken in dorsiflexion-external rotation were most predictive of deep deltoid ligament disruption after distal fibular fracture. Under this stress condition, a medial clear space of > or =5 mm was the most reliable predictor of deep deltoid ligament status."


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(OBQ07.39) The Cotton test evaluates which of the following structures? Review Topic

QID:700
1

Calcaneofibular ligament

2%

(9/373)

2

Lateral ulnar collateral ligament of the elbow

3%

(11/373)

3

Ligamentum flavum

0%

(1/373)

4

Anterior talofibular ligament

4%

(14/373)

5

Ankle syndesmosis

91%

(338/373)

Select Answer to see Preferred Response

PREFERRED RESPONSE 5

The inferior tibiofibular syndesmosis is a fibrous articulation consisting of four ligaments; the elasticity of these ligaments permits axial, vertical, anterior, posterior, and mediolateral motion at the ankle syndesmosis during weight bearing.

Of note, the Cotton test was originally described around 1910 by Frederic J. Cotton as the "talar glide test" evaluating the medial/lateral translation of the talus in the mortise. A positive result indicates disruption of the ankle syndesmosis in the face of an ankle injury.

Nielson et al reported that the level of the fibular fracture does not correlate reliably with the integrity or extent of the interosseous membrane (IOM) tears identified on MRI in operative ankle fractures. Therefore, one cannot consistently estimate the integrity of the IOM and subsequent need for transsyndesmotic fixation based solely on the level of the fibular fracture. This supports the need for intraoperative stress testing (ie, external rotation stress or Cotton test) of the ankle syndesmosis in all operative ankle fractures.

The study by Leeds et al noted a correlation between syndesmosis reduction (initial and final) and outcomes (radiographic and clinical).

The attached video shows the Cotton test during an ankle fixation procedure.

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(OBQ07.88) After undergoing the treatment seen in Figure A, when should a patient be expected to safely operate the brakes of an automobile? Review Topic

QID:749
FIGURES:
1

6 weeks

13%

(40/313)

2

2 -4 weeks

2%

(5/313)

3

6 months

4%

(14/313)

4

8-9 weeks

60%

(188/313)

5

3 months

21%

(66/313)

Select Answer to see Preferred Response

PREFERRED RESPONSE 4

Figure A shows a patient after an open reduction and internal fixation of a bimalleolar ankle fracture.

Egol et al showed that by nine weeks, the total braking time of patients who had undergone fixation of a displaced right ankle fracture returns to the normal, baseline value.

Egol et al, also found that appropriate braking time returns at a point 6 weeks after initiation of weightbearing after treatment of lower extremity long bone and periarticular fractures, as examined with a driving simulator. No differences were seen in return of braking time between periarticular fractures and long bone injuries.


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(OBQ07.223) Appropriate treatment of the bimalleolar ankle fracture shown in Figure A includes which of the following? Review Topic

QID:884
FIGURES:
1

Bridge plating of the fibula with oblique medial malleolar screws

4%

(17/403)

2

Antiglide plating of the fibula with oblique medial malleolar screws

8%

(34/403)

3

Intramedullary fibular screw with medial malleolar tension banding

2%

(8/403)

4

Fibular plating with open correction of plafond impaction with medial malleolar antiglide plate

71%

(288/403)

5

Fibular plating with open correction of syndesmosis and oblique medial malleolar screws

13%

(54/403)

Select Answer to see Preferred Response

PREFERRED RESPONSE 4

A supination-adduction type injury consists of a vertical displaced medial malleolus fracture with marginal impaction of the tibial plafond and a low transverse fibula fracture. This type of injury is also associated with hyperdorsiflexion. The mechanism of a supination–adduction injury to the ankle results in a low transverse lateral malleolus avulsion and a vertical fracture of the medial malleolus secondary to inversion of the talus in the ankle mortise. The initial injury is a rupture of the lateral ankle ligaments or avulsion of the lateral malleolus. As the talus continues to invert, the medial malleolus is pushed to failure and fractures in a vertical fashion. The correct treatment for this type of injury is open reduction and internal fixation (ORIF) with correction of the impacted articular component. Screws alone or a tension band would not provide a vertically stable construct.

In the referenced article by McConnell et al, 8 ankle fractures of this variety were all treated with open reduction and internal fixation, two with medial screws perpendicular to the fracture and the other 6 with medial screws and a one third tubular antiglide plate. 6 of the patients treated in the study had excellent results after 2.5 years of follow up, the other 2 had good results after 2.5 years.

Example of a representative fixation construct of the injury is shown in Illustration A.

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(OBQ06.28) A 34-year-old woman twists her right ankle stepping off the city bus. An AP ankle radiograph is provided in Figure A. Which of the following statements accurately describe this radiograph? Review Topic

QID:139
FIGURES:
1

The tibiofibular overlap is less than 3 mm

17%

(165/959)

2

The fibula demonstrates a Weber C fracture pattern

6%

(55/959)

3

The tibiofibular clear space is less than 4 mm

60%

(575/959)

4

The fracture is consistent with a Lauge-Hansen pronation-external rotation injury pattern

14%

(138/959)

5

The medial clear space is greater than 5 mm

3%

(24/959)

Select Answer to see Preferred Response

PREFERRED RESPONSE 3

The AP radiograph demonstrates a stable, minimally displaced Weber B ankle fracture. It is consistent with a Lauge-Hansen supination-external rotation injury pattern.

Harper et al performed cadaveric measurements to define normal radiographic values for standard ankle imaging. The tibiofibular overlap is defined as the horizontal distance from the lateral border of the posterior tibial malleolus (the incisura fibularis) and the medial border of the fibula at the point where the posterior malleolus is widest on an AP radiograph should be great than 6 mm. Tibiofibular clear space is defined as the horizontal distance between the medial border of the fibula and the lateral border of the anterior tibial prominence on an AP radiograph, and should be <6mm. The medial clear space, defined as the distance between the lateral aspect of the medial malleolus and the medial border of the talus at the level of the talar dome on the mortise radiograph should be less than 4 mm.

Ostrum et al performed a radiographic study on human volunteers and noted gender differences. In this study, normal tibial clear space should be less than 5.2 mm in women and less than 6.5 mm in men. The tibiofibular overlap should be greater than 2.7 mm in women and greater than 5.7 mm in men.

Illustration A is an example of the proper measurement of the tib-fib clear space.

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(OBQ06.85) The talocrural angle of an ankle mortise x-ray is formed between a line perpendicular to the tibial plafond and a line drawn: Review Topic

QID:196
1

perpendicular to the medial clear space

1%

(12/1024)

2

parallel to the talar body

21%

(211/1024)

3

between the tips of the malleoli

74%

(760/1024)

4

perpendicular to the shaft of the fibular

1%

(9/1024)

5

parallel to the subtalar joint

3%

(31/1024)

Select Answer to see Preferred Response

PREFERRED RESPONSE 3

The talocrural angle is formed by the intersection of a line perpendicular to the plafond with a line drawn between the malleoli (average = 83+/-4deg). When the lateral malleolus is shortened secondary to fracture, this can lead to increased talocrural angle. This malunion leads to lateral tilt of the talus.

Phillips et al looked at 138 patients with a closed grade-4 supination-external rotation or pronation-external rotation ankle fracture. Although the conclusions were limited due to poor follow up, they found the difference in the talocrural angle between the injured and normal sides was a statistically significant radiographic indicator of a good prognosis.

Pettrone et al looked at a series of 146 displaced ankle fractures, and the effect of open or closed treatment, and internal fixation of one or both malleoli. They found open reduction proved superior to closed reduction, and in bimalleolar fractures open reduction of both malleoli was better than fixing only the medial side.

Illustrations A and B are demonstrations of the talocrural angle.

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(OBQ06.115) Lateral malleolus fractures can be treated with a variety of techniques, including posterior antiglide plating or lateral neutralization plating. What is an advantage of using lateral neutralization plating instead of posterior antiglide plating? Review Topic

QID:301
1

Decreased joint penetration of distal screws

1%

(9/829)

2

Increased rigidity

5%

(42/829)

3

Decreased need for delayed hardware removal

2%

(14/829)

4

Decreased peroneal irritation

88%

(728/829)

5

Improved distal fixation

4%

(33/829)

Select Answer to see Preferred Response

PREFERRED RESPONSE 4

Posterior antiglide plating is a technique that involves placement of a plate on the posterior aspect of the distal fibula, using the plate as a reduction tool and direct buttress against distal fracture fragment displacement.

Schaffer et al showed from a biomechanical standpoint that posterior antiglide plating was superior to lateral neutralization plating for distal fibula fracture fixation.

Weber et al reported a (30/70) 43% rate of plate removal secondary to peroneal discomfort. In addition, peroneal tendon lesions were found in 9 of the 30 patients.


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(OBQ06.140) The Lauge-Hansen classification of ankle fractures identifies characteristic fracture patterns based on mechanism of injury. What is the mechanism for the fracture pattern shown in Figure A? Review Topic

QID:326
FIGURES:
1

Supination-External Rotation

7%

(29/413)

2

Pronation-External Rotation

2%

(7/413)

3

Pronation-Abduction

3%

(12/413)

4

Supination-Adduction

86%

(354/413)

5

Supination-Abduction

2%

(10/413)

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PREFERRED RESPONSE 4

The 4 categories in the Lauge-Hansen classification are: supination-adduction, supination-external rotation, pronation-external rotation, and pronation-abduction.

The typical fracture pattern of supination-adduction is demonstrated in figure A and consists of a tension failure (transverse) fracture of the lateral malleolus combined with a vertical fracture of the medial distal tibia. There is frequently comminution where the fracture begins on the tibial plafond. This is caused by compression from the medial talar dome.


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(OBQ06.250) What is the most appropriate plating technique utilized for the medial malleolus fracture typically seen in a displaced supination-adduction ankle fracture? Review Topic

QID:261
1

Tension band plating

3%

(11/334)

2

Antiglide plating

80%

(266/334)

3

Bridge plating

4%

(12/334)

4

Neutralization plating

11%

(38/334)

5

Submuscular plating

2%

(6/334)

Select Answer to see Preferred Response

PREFERRED RESPONSE 2

A supination-adduction ankle fracture leads to a vertical fracture of the medial malleolus. Traditional fixation of the medial malleolus with oblique screws from the tip of the malleolus directed proximally will ineffectively protect against shear forces at the fracture site; these also are directed quite obliquely to the vertical fracture line, and therefore have poor biomechanical resistance to failure. An antiglide plate is used medially to prevent displacement of the fracture segment due to shear forces.

According to the referenced article by Toolan et al, placement of two horizontal (perpendicular to the fracture line) lag screws from medial to lateral are biomechanically the most important aspect of the construct whether a plate is used or not.


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(OBQ05.89) When comparing the fibular plating techniques shown in Figures A and B, the plate position shown in Figure B is associated with which of the following? Review Topic

QID:975
FIGURES:
1

Increased stiffness

7%

(52/763)

2

Increased strength

5%

(35/763)

3

Decreased rate of hardware prominence

6%

(47/763)

4

Increased risk of intra-articular screw penetration

70%

(531/763)

5

Increased peroneal tendinitis

13%

(97/763)

Select Answer to see Preferred Response

PREFERRED RESPONSE 4

Figure A shows an antiglide (posterior) plating of the distal fibula, while Figure B shows a lateral neutralization plating of the distal fibula. Both methods are acceptable, but posterior antiglide plating is associated with increased construct stiffness and strength, decreased hardware prominence, decreased rates of ankle joint screw penetration, and improved biomechanical findings in osteoporotic bone. However, posterior plating is associated with an increased rate of peroneal tendonitis and irritation. Illustration A shows a lateral radiograph of a posterior fibular plate.

The referenced article by Ostrum et al is a case series of 32 patients who had antiglide plating; he reported a 100% union rate, 95% patient satisfaction rate, and only 4/32 reported peroneal tendinitis, with all resolving by 2 months.

The other referenced article by Schaffer et al reported that the posterolateral antiglide plate demonstrated improved biomechanical stability as compared to the lateral plating, with increased construct stiffness and load to failure.

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(OBQ05.205) Coupled with reduction of the syndesmosis, which of the following interventions is most important when surgically addressing the ankle malunion shown in Figure A? Review Topic

QID:1091
FIGURES:
1

Placement of an osteochondral allograft

2%

(31/1624)

2

Fibular lengthening osteotomy

64%

(1035/1624)

3

Calcaneofibular ligament release

2%

(38/1624)

4

Medial malleolar shortening osteotomy

1%

(18/1624)

5

Deltoid ligament imbrication

31%

(497/1624)

Select Answer to see Preferred Response

PREFERRED RESPONSE 2

Late correction with a corrective osteotomy of a fibular malunion associated with diastasis of the ankle mortise (Illustrations A and B) is an effective means of salvaging function in a joint otherwise destined to be stiff and painful.

The referenced study by Offierski et al reports that the factors that determined the success of the revision were the duration of the malunion, the quality of the reduction achieved, and the condition of the articular cartilage at the time of revision.

The referenced study by Chao et al reported that the fibular lengthening osteotomy was crucial in regaining the anatomy and stability of the ankle mortise.

The referenced study by Weber et al is a review of the technique of such an osteotomy, with commentary regarding its clinical success even if mild degenerative changes are seen. They also note that no differences are seen in outcomes between oblique and step-cut osteotomies.

The referenced study by Weber and Simpson is a case series of corrective lengthening osteotomies after malunited ankle fractures. They report that a lengthening and/or rotational osteotomy of a malunited fibula is successful in preventing further ankle arthrosis if no more than minimal degenerative radiographic changes are seen.

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(OBQ04.23) A 32-year-old taxi driver sustains a displaced supination external rotation ankle injury after slipping off of a curb. He subsequently undergoes surgical fixation, and a post-operative radiograph is shown in Figure A. At the eight-week postoperative visit, you are asked to fill out a return to work form. How long from today’s visit will his braking time be expected to return to normal? Review Topic

QID:134
FIGURES:
1

Two weeks ago

12%

(56/460)

2

One week from now

49%

(226/460)

3

Three weeks from now

9%

(41/460)

4

Six weeks from now

21%

(96/460)

5

Eight weeks from now

8%

(39/460)

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PREFERRED RESPONSE 2

Patients recover the ability to safely operate the brakes of an automobile 9 weeks following operative repair of an ankle fracture. Because this patient is currently 8 weeks out from surgery, his braking time will be expected to return to normal one week from now.

Egol et al studied the time braking ability returns to normal in patients with operatively treated ankle fractures. Patients were studied at 6, 9, and 12 weeks postoperatively and compared to healthy controls. It was determined that total breaking time returned to normal by 9 weeks.


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(OBQ04.49) A 33-year-old male is involved in a motor vehicle accident and suffers a right pilon fracture. Which of the bone fragments labeled on the distal tibia in the axial CT scan shown in Figure A is attached to the posterior tibiofibular ligament? Review Topic

QID:110
FIGURES:
1

A

1%

(8/1105)

2

B

5%

(53/1105)

3

C and B

2%

(20/1105)

4

D

30%

(330/1105)

5

A and D

62%

(680/1105)

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PREFERRED RESPONSE 4

Figure A is an axial CT scan slice of an intra-articular distal tibia fracture. The bands of the posterior tibiofibular ligament pass obliquely from the fibula to the posterolateral aspect of the distal tibia. The ligaments of the ankle often remain intact after a pilon fracture producing the major fracture segments consisting of posterolateral or Volkmann's fragment (labeled D), the anterolateral or Chaput fragment (labeled B), and the medial fragment (labeled C). The fibula is labeled A. Any surgical approach taken to treat this injuries should respect these attachments.

Michelson reviews the important role of ankle ligamentous anatomy in his study on rotational ankle fractures.

Hermans et al review the anatomy of the ankle syndesmosis and state that stress on the posterior tibiofibular ligament results more often in a posterior malleolus avulsion fracture than in a rupture of the ligament. They go on to state that with direct reduction of the posterior malleolus avulsion fracture, the syndesmosis can often be stabilized.

Illustration A shows the posterior tibiofibular ligament highlighted in red on MRI imaging in a LEFT ankle (the CT image in the question is of a RIGHT ankle).

ILLUSTRATIONS:

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(OBQ04.243) A 32-year-old female sustained a bimalleolar ankle fracture and was treated with open reduction and internal fixation four months ago. A radiograph of her ankle is shown in Figure A. Recommended management should consist of? Review Topic

QID:1348
FIGURES:
1

Physical therapy for ambulation assistance and proprioception training

2%

(7/351)

2

Short leg bracing

2%

(6/351)

3

Revision open reduction and internal fixation with open syndesmosis reduction

77%

(271/351)

4

Addition of syndesmosis screw from fibula to tibia

17%

(60/351)

5

Open medial ankle ligament reconstruction

1%

(4/351)

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PREFERRED RESPONSE 3

This patient requires revision open reduction and internal fixation of her syndesmosis as post-operative radiographs demonstrate a severely malaligned ankle with obvious syndesmosis widening and fibular shortening.

Malalignment following ankle fracture fixation can alter the anatomical axis of the joint, articular congruency, and normal load distribution. This predisposes the patient to the development of chronic pain, functional impairment, and finally early post-traumatic ankle arthritis.

Marti et al. retrospectively reviewed the outcomes of 31 patients with malunited ankle fractures who underwent reconstructive osteotomies. The authors found that reconstruction resulted in good or excellent results in the majority of patients. They also note that minor post-traumatic arthritis was not a contraindication to reconstruction.

Ramsey et al. evaluated 23 cadaveric ankles using a carbon black transference technique to determine the contact area in the dissected tibiotalar articulations, with the talus in neutral position and displaced one, two, four, and six millimeters laterally. They found that 1 mm of lateral talar displacement resulted in a 42% decrease in tibiotalar contact area.

Figure A is a x-ray demonstrating severe malalignment of a bimalleolar ankle fracture following fixation of the fibula and medial malleolus. There is obvious shortening of the fibula and lateral shift and valgus tilt of the talus associated with a disrupted syndesmosis.

Incorrect Answers:
Answer 1 & 2: Physical therapy and short leg bracing are not indicated at this point as the anatomical malalignment needs to first be addressed via revision surgery.
Answer 4: The addition of a syndesmosis screw will not successfully reduce the syndesmosis as it has been chronically malreduced and will require open reduction and debridement prior to syndesmosis screw fixation.
Answer 5: Open medial ankle ligament reconstruction is insufficient in isolation to provide mechanical stability to the ankle fractures with syndesmosis disruption.


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