Chapter 103 - Fractures of the Ankle and Tibial Plafond

Question 1

how does the fibula move in the incisura as the foot goes from plantar flexion to dorsiflexion?

Answer 1

fibula moves proximal and externally rotates

Question 2

where does the sural nerve lie at the level of the ankle joint?

Answer 2

immediately lateral to the achilles tendon

Question 3

moving from proximal to distal on the fibula - describe the lauge hansen classification

Answer 3

PER - high fibula, transverse fracture
PAB - communited high fibula
SER - at the level of the syndesmosis short/intermediate oblique
SAD - transverse distal fibula fx

Question 4

posterolateral approach to the ankle

Answer 4

betwee nperoneus longus and achilles

must elevate the fhl off the fibula

Question 5

AITFL avulsion fracture off the tibia known as what fragment?

Answer 5

chaput fragment

Question 6

radiographic parameters on the mortise view

Answer 6

1. talocrural angle should be 83 +/- 4 degrees or with 5degrees of the contralateral ankle
2. medial clear space 4-5mm
3. tibiofibular clear space <6mm

Question 7

most common malunion in an ankle fracture

Answer 7

lateral mal malreduced - shortened and rotated

Question 8

what radiographic indicators of malunion suggest poor outcome

Answer 8

widened medial clear space
large posterior malleolar fragment

Question 9

mechanism of injury for a plafond injury?

Answer 9

axial load of the talus onto the plafond

Question 10

when should CT be performed in plafond fractures?

Answer 10

• if planned temporary spanning ex fix:
  get the CT after spanning
• if ex fix is planned definitive fixation:
  get the CT before surgery

Question 11

fracture fragments in a plafond fx

Answer 11

• AITFL: chaput fragment anterolateral
• PITFL: volkmann fragment posterolateral

Question 12

staged ex fix followed by definitive fixation in pilons has done what to infection rate

Answer 12

brought it from like 40% to 0-6% by allowing soft tissues to reover before surgerizing

Question 13

what are the outcomes of definitive ex fix v orif in tibial plafond fractures?

Answer 13

increased incidence of fair to poor articular reduction in the ex-fix group compared to the ORIF group

Question 14

where do the components of the deltoid ligament arise and insert onto

Answer 14

superficial deltoid arises at the anterior malleolus
deep deltoid arises on the posterior malleolus of the medial malleolus