Review Question - QID 8958

Shortening of the fibula would lead to syndesmotic malreduction in this fracture pattern. To restore the syndesmotic relationship of the tibia and fibula, the fibula must be anatomically restored; this includes length, alignment, and rotation of the fibula.

Successful reduction of the fibula fracture is generally done in an open manner, and open reduction of the syndesmosis is also helpful to achieve anatomic reduction. Percutaneous or open clamping of the syndesmosis can be harmful if the vector of the clamp is off-axis of the joint. Contralateral ankle radiographs are also a useful method to assess anatomic syndesmosis reduction.

Gardner et al. (2015) report that accurate reduction and stable fixation of the syndesmosis is critical to maximize patient outcomes. They also state that multiple types of malreduction can occur, including translational, rotational, and overcompression.

Gardner et al. (2006) reviewed patients undergoing ankle and syndesmotic fixation. They reported that 24% had evidence of radiographic postoperative diastasis while 52% had incongruity of the fibula within the incisura on CT scan. They concluded that many malreductions on CT scan went undetected by plain radiographs.

Miller et al. performed a cadaveric study that assessed clamp and screw placement and the relationship of malreductions with clamping at different angles to the ankle. They reported that clamps placed at 15° and 30° significantly displaced the fibula in external rotation and caused significant overcompression of the syndesmosis. Thirty-degree lateral screws caused significant anteromedial displacement, external rotation, and overcompression of the syndesmosis. The 15° posterolateral screws also caused significant external rotation and overcompression of the syndesmosis.

Figure A shows a bimalleolar ankle fracture with syndesmotic injury. Illustration A shows a shortened fibula with ankle joint incongruity.

Incorrect Answers:
Answer 1: Repair of the deltoid ligament will not correct fibular malreduction.
Answer 3: Fibular impingement is seen with lengthening of the fibula.
Answer 4: Peroneal tendon tears are not a direct result of fibular shortening; these can be seen with fibula fractures and are often detected later.
Answer 5: Fibular nonunion is associated more with over-lengthening of a fibula if a gap is present.