1 Previous steps topenlarge
Before fixation of the Volkmann's triangle, the fractures of the fibula and the medial malleolus are fixed. Start the treatment with fixation of the fibula.
2 Preliminary consideration topenlarge
A small fragment (< 25% of the articular surface) with joint stability after malleolar reconstruction = fixation is not necessary.
A medium sized fragment ( > 25% of the articular surface), without long proximal extension = fixation with lag screw(s).
A large fragment ( > 25% of the articular surface) with long proximal extension = fixation with lag screw and buttress plate.
3 Reduction top
Usually, following fixation of the fibular shaft fracture and dorsiflexion of the foot, reduction of the Volkmann’s triangle is achieved through ligamentotaxis.
If necessary, hold the Volkmann’s fragment in place with a dental hook through the lower extent of the lateral approach used for the fixation of the fibula.
Provisional fixation of the Volkmann’s triangle is achieved with two 1.25 mm guide wires inserted through the stab incision from anteromedial to posterolateral. The guide wires should be perpendicular to the fracture plane, at the desired positions of the planned screws. The thread of the cannulated guide wire must be engaged just through the far cortex.
Care must be taken not to damage the neurovascular bundle and the tendons that lie on the anterior surface of the tibia.
Check reduction and position of guide wires under image intensification.
4 Fixation topenlarge
Determine the length of the screw with the appropriate depth measuring device.
The chosen 3.5 mm partially threaded cannulated screw must lie with its threads completely beyond the fracture line and totally within the Volkmann’s triangle in order to achieve interfragmentary compression. If possible, engage the far cortex. Use a washer.
If the thread of the 3.5 mm partially threaded screw should come to lie on both sides of the fracture, insert a 3.5 mm fully threaded cannulated screw as a lag screw instead, overdrilling the anterior tibia to form a 3.5 mm gliding hole.
Insert first screw
Drill a hole over the more lateral guide wire, through both fragments, with a 2.7 mm cannulated drill bit. Tap the anterior tibial cortex with the 3.5 mm cannulated tap and protection sleeve.
Insert the selected 3.5 mm partially threaded cannulated screw with a washer.
Insert the second screw
Remove the first guide wire.
As a rule, a screw which is 5 mm longer than the measured size must be chosen for the second screw as the more medial portion of even a large Volkmann’s triangle is often not deep enough to accommodate the whole of the threaded portion of the screw.
The screw tip may therefore protrude a little posteriorly.
If the thread of the 3.5 mm partially threaded screw would still come to lie on both sides of the fracture, or if you do not want the tip of the screw to protrude into the posterior soft tissues, insert a 3.5 mm fully threaded cannulated screw as a lag screw instead, overdrilling the anterior tibia to form a 3.5 mm gliding hole.
5 Alternative fixation topenlarge
Posterior lag screw
Alternative fixation with a cannulated lag screw inserted in an posterior-anterior direction.
If the Volkmann’s triangle has a long proximal extension, fixation with a lag screw and a buttress plate is indicated.
This may require a separate posteromedial approach to the posterior tibia, as an extension of any medial approach, as the back of the tibia is very difficult to reach at this level by dissection behind the fibula.
6 Next steps topenlarge
Determine now, whether the insertion of a tricortical positioning screw is necessary to achieve appropriate joint stability.