Tib, Fib, Ankle Flashcards
4 ligaments that compose the syndesmotic ligament complex:
1: anterior inferior tibiofibular ligament
2: posterior inferior tibiofibular ligament (thicker and stronger than anterior)
3: transverse tibiofibular ligament (inferior to posterior)
4: interosseous ligament (distal continuation of the interosseous membrane)
Components of the deltoid ligament complex:
Superficial: originate on the anterior colliculus
1: tibionavicular ligament (suspends the spring ligament)
2: tibiocalcaneal ligament (prevents valgus displacement)
3: talotibial ligament (most prominent of the 3)
Deep: deep anterior and posterior tibiotalar (primary medial stabilizer against lateral displacement)
3 ligaments of the fibular collateral ligament
Anterior talofibular, posterior talofibular, calcaneofibular
Radiographic eval of ankle injuries:
AP, Lateral, and mortise view
Indication of medial or lateral joint disruption with Talar Tilt
Difference in width of the medial and lateral aspects of the superior joint space >2 mm
Positioning of the foot to take mortise view X-ray
Foot in 15-20 degrees of internal rotation (to offset the intermalleolar axis)
The tibiofibular clear space should be less than how many mm?
6 mm
Approximate degrees of the talocrural angle
83 +- 4 degrees (from picture); or between 8 and 15 degrees (angle subtended bt the intermalleolar line and a line parallel to the distal tibial articular surface. Angle should be between 2 to 3 degrees of uninjured ankle.
Medial clear space should be equal to the superior clear space between the talus and the distal tibia and less than how many degrees on standard X-ray
Less than or equal to 4 mm; greater than 4 indicates lateral talar shift
Classification system used for rotational ankle fractures
Lauge-Hansen (takes into account 1: the position of the foot at the time of injury, and 2: the direction of the deforming force)
4 possible position-direction of force combinations with the Lauge-Hansen classification system
Supination-adduction
Supination-external rotation
Pronation-adduction
Pronation-external rotation
Stages of supination-adduction with lauge-Hansen
Stage 1: transverse avulsion type fx of the fibula distal to the level of the joint or a rupture of the lateral collateral ligaments
Stage 2: vertical medial malleolar fx
Stages of supination-external rotation (40-75% of malleolar fxs)
Stage 1: anterior tib-fib sprain +- avulsion fx
Stage 2: typical spiral/short oblique fx of distal fibula
Stage 3: disruption of post tibfib ligament or fx of post malleolus
Stage 4: transverse avulsion fx of medial malleolus or rupture of deltoid ligament
Stages of pronation-external rotation
Stage 1: transverse fx of medial malleolus or rupture of deltoid lig
Stage 2: disruption of the ant tibfib lig +- avulsion fx at insertion site, Chaput’s tubercle
Stage 3: spiral fx of distal fib at or above syndesmosis; medial injury with high fib fx
Stage 4: rupture of post tibfib lig or avulsion fx of posterolateral tibia
Stages of pronation-adduction with lauge-Hansen classification of rotational ankle fractures
Stage 1: transverse fx of medial malleolus or rupture of deltoid lig
Stage 2: rupture of syndesmotic lig or avulsion fx at their insertion sites
Stage 3: transverse or oblique fx of distal fibula at or above level of syndemsosis, producing lateral comminution or butterfly fragment
Fx classification based on the level of the fibular fracture
Danis-Weber (more proximal the fx, the greater risk of syndesmotic injury
Maisonneuve fx:
Ankle injury with a fx of the proximal third of the fibula. This is a pronation-external rotation type injury
Curbstone fx
Avulsion fx off the posterior tibia 2/2 tripping mechanism
Maisonneuve fx:
Ankle injury with a fx of the proximal third of the fibula. This is a pronation-external rotation type injury
LeForte-Wagstaffe fx
Anterior fibular tubercle avulsion fx by ant tibiofibular lig, usually associated with LH SER type fx pattern
Tillage-Chaput fx
Avulsion of the ant tibial margin by the ant tibiofibular lig is the tibial counterpart of the LeForte-Wagstaffe
Classic sign for posterior colliculus fx on external rotation view
Supramalleolar spike
Indications for Nonoperative tx of ankle fxs: 3
1: nondisplaced, stable fx with intact syndesmosis
2: displaced fx for which stable anatomic reduction of the ankle mortise is achieved
3: unstable, multiple trauma pt
Operative tx for lateral malleolar fxs distal to the syndesmosis
Lag screw or kirschner wires with tension banding
Operative tx of lateral malleolar fxs at or above the syndesmosis
Combination of lag screws and plate (important to restore length and rotation)
Indications for operative fixation of medial malleolus fx (4)
1: concomitant syndesmotic injury
2: persistent widening of the medial clear space following fibula reduction
3: inability to obtain fibular reduction
4: persistent medial fx displacement after fibular fixation
Operative tx of medial malleolar fxs
Stabilized with cancellous screws or figure of eight tension banding
Indications for fixation of posterior malleolus fx (3):
1: involvement of >25% of the articular surface
2: >2mm displacement
3: persistent posterior subluxation of the talus
Operative tx for posterior malleolus fx:
Anterior to posterior lag screw or posteriorly placed plate and/or screws
Placement of a syndesmotic screw for stabilization
1.5 to 2.0 cm above the plafond from the fibula to the tibia. Note: either 3 or 4 cortices and either 3.5 or 4.5 mm screws
Loss of reduction is reported in what % of unstable ankle injuries treated nonoperatively?
25%
Classification for Pilon (plafond) fxs
Ruedi and Allgower