1 Principles topenlarge
Anatomical reduction of the articular fracture component and fixation with lag screws (absolute stability) is mandatory.
After reduction of the articular fracture component, anatomical reduction of the metaphyseal component has to be achieved.
In order to avoid varus collapse on the medial side double plating should be considered and if necessary carried out. In these fracture patterns the placement of the medial plate may be anteromedial rather than posteromedial. This depends of course on the fracture pattern and forces which have to be neutralized.
2 Reduction topenlarge
Indirect reduction may be achieved by external manipulation of the fracture fragment with clamps. In cases where adequate closed reduction is not achieved, the joint must be opened to carry out an open reduction.
If one is trying to carry out the procedure without opening the joint then reduction must be checked either with image intensification or with arthroscopy.
Pearl: clamp over plate
If you intend to keep the clamp on throughout the whole procedure it is best to slip the plate under the clamp prior to tightening the clamp to maintain reduction. Under these circumstances you determine which screw hole is best for the placement of the tip of the clamp from the pre-operative plan and intra-operative trial.
Anatomical reduction of the articular surface is mandatory. Secure reduction and provisional fixation with K-wires.
Positioning of the knee is important for correct reduction and fixation. If the knee has a valgus injury, then the knee should be held with more varus positioning to ensure a good reduction. If the knee has a varus injury (medial condyle) then valgus positioning during reduction is important.
3 Fixation top
The positioning of the buttress plate is important as the ideal place is at the tip of the fragment and perpendicular to the fracture plane.
Lateral column fixation
The lateral plate is inserted in the space between muscle and periosteum. The plate must be contoured carefully to the bone. Fixation begins with the insertion of a lag screw to stabilize the joint. If this can be done through the plate the first screw inserted is then through the plate.
Click here for a detailed description of the lag screw technique.
Compression of the metaphyseal fracture component
Using the dynamic compression principle screws are inserted eccentrically into one or two plate holes close the metaphyseal fracture line.
All remaining screws are placed in a neutral way.
Medial column fixation
The medial plate may be applied either posteromedially as we have shown in all our illustrations or anteromedially. The position of the plate is determined by a number of important factors such as the direction of the fracture lines, the forces to be neutralized, the exposure already made, and finally which application will allow for the least traumatic but biomechanically still sound application.
In this illustration we have used a cortex plate applied posteromedially. For fixation we have used only cortical screws.
Illustration showing the final result.
Alternative: angular stable plate
If one is using a angular stable implant (eg, LISS or the lateral tibial plate with locking screws) the application of a medial plate is not necessary.
Click here for a detailed description of the LISS application.