A joint-bridging external fixator is fixed to the femur and the tibia while the fracture zone is left virtually untouched (it is bridged). Provisional reduction is achieved with distraction.
When external fixation is used to bridge the knee joint it is always only for temporary fixation. Prolonged immobilization will lead to difficulties with knee mobility.
It is rapidly applied without need for intraoperative x-rays and can be adjusted later.
Details of external fixation are described in the basic technique for application of modular external fixator.
Specific considerations for the knee are given below.