Davos Courses

Executive Editor: Steve Krikler

Authors: Paulo Barbosa, Felix Bonnaire, Kodi Kojima, Paul Demmer

Malleoli

back to skeleton

Glossary

Back to main procedure

1 Principles top

Indication for tension band wiring

The tension band wiring is indicated for fixation of small medial fragments, avulsion fractures, or osteoporotic bone.


enlarge

Tension band principle

The tension band converts tensile forces into compression forces.

To be able to use a tension band, the opposite cortex needs to have contact and be able to resist compression.


enlarge

The figure-of-eight wire loop lies on the medial (tension) surface of the medial malleolus and acts as a tension band when tightened.

Choose a wire of sufficient strength to withstand the tensile forces generated in the figure-of-eight loop (0.8 - 1.0 mm).

2 Reduction top

Preparing the fracture site

Remove any minor bone fragments which are blocking reduction. Do not strip the periosteum more than necessary.

It is important to visualize and inspect the joint, searching for bone and cartilage fragments detached from the medial malleolus or from the talus.


enlarge

Reduction with small pointed reduction forceps

Reduce the fracture with small pointed reduction forceps.

Do not strip the periosteum more than necessary.

3 Fixation top

enlarge

Insert the posterior K-wire

Using 1.6 mm K-wire, drill the posterior wire as perpendicularly as possible to the fracture plane.

Take special care not to cross the fracture line too close to the joint.

Note
Avoid penetration of the ankle joint, or the lateral tibial cortex.


enlarge

Insert the anterior K-wire

A second 1.6 mm K-wire is inserted into the medial malleolus, parallel to the first wire.

These two K-wires stabilize the fracture against rotation and will be used to anchor the figure-of-eight wire distally.

Check the reduction under image intensification.

Note
Care must be taken to avoid intraarticular positioning of the K-wires.

4 Screw insertion top

enlarge

Drill a 2.5 mm hole, with the protection of a drill sleeve, 2-3 cm above the level of the horizontal joint line, aiming the drill bit slightly inferiorly to avoid screw pullout.

Tap the medial cortex with the 3.5 mm tap and protection sleeve.

Insert a unicortical screw, ranging from 20-30 mm in length and fitted with a washer. Leave a space for the wire of 2-3 mm between the bone and the washer.

Note
In osteoporotic bone, this screw must be bicortical.


enlarge

Wire application

Prepare the 0.8 -1.0 mm wire by making a loop at approximately one third along its length.

Pass the shorter segment of the wire close to the bone around the two K-wires.

Pass the longer segment of the wire (bearing the loop) around the screw between bone and washer, forming a figure-of-eight.

Twist the free ends together.


enlarge

Some surgeons prefer to use two pieces of wire, twisting the ends together to create the figure of eight loop with a twist on each side.


enlarge

Wire tightening

The wire twist is loosely prepared ensuring that each end of the wire spirals equally, forming a double helix – avoid twisting one wire around the other (straight) wire.


enlarge

The wire is tensioned by pulling on the twists.


enlarge

The slack is then taken up by further twisting. Repeat this until the desired tension is achieved. Both loops must be tightened at the same time and in the same direction, to achieve equal tension on both arms of the wire.

Tighten the screw carefully. Trim the twists and turn both ends towards the tibia in order not to irritate the soft tissues later.

Note
In osteopenic bone care must be taken to avoid excessive tensioning.


enlarge

Finishing fixation

Cut the 2 K-wires obliquely, approximately 1 cm from their insertion points and, with the help of a bending iron and forceps, bend through 180 degrees.

The K-wires are then driven home, sinking their curved ends into the bone to prevent backing out and skin injury.

Take final x-rays in both planes to check the results.

Back to main procedure

v1.0 2015-12-04