The LISS plate is an internal fixator used as an extramedullary splint, fixed to the two main fragments, leaving the intermediate fracture zone untouched. Anatomical reduction of intermediate fragments is neither sought nor necessary. Direct manipulation of intermediate fragments would risk disturbing their blood supply. If the soft-tissue attachments to these fragments are preserved, and the fragments are generally aligned, healing is unimpaired.
Alignment of the main shaft fragments can be achieved indirectly, using various aids.
Mechanical stability, provided by the bridging fixator, is adequate for gentle functional rehabilitation and results in satisfactory indirect healing (callus formation) of the diaphysis.
LISS fixation relies on the principle of bridge plating. It therefore works best in setting of a comminuted metaphyseal fracture. By contrast, standard compression plating (eg, blade plate, ORIF with LCP-DF) is used when the metaphyseal component of the fracture has one or two simple planes. This is an important point: a common failure of the LISS is seen when a simple plane fracture is treated with the relatively flexible LISS plate and left with a gap. This can result in a high rate of nonunion.