Inserting the cerclage wire
Note: We will here illustrate the technique using a complete articular, frontal/coronal wedge fracture.
Choose a wire of enough strength to withstand the tensile forces generated in the cerclage (1.0 – 1.25 mm diameter).
The wire should be as close as possible to the bone throughout its whole course both superiorly and inferiorly. The use of a curved large bore injection needle may be helpful.
The wire is then similarly threaded around the circumference of the body of the patella and its lower pole, as illustrated.
Loosely prepare the wire twist ensuring that each end of the wire spirals equally - the twist should not comprise one spiral around a straight wire.
Carefully tighten the wire while pulling away from the patella as the wires are twisted. Avoid over-tightening as this may distort the overall shape of the patella.
The wires should be twisted at least 5 times to prevent fixation failure. When stainless steel wires tighten, they will lose the surface sheen and if tightened further the wire may break.
When the correct tension is achieved, twist and trim the wire ends.
Care should be taken finally to position the twisted wire into deeper soft-tissue muscle layers, if possible.
Verify the reduction by palpation of the retro patellar surface if possible.