Based on the principle of minimally invasive surgery, a new type of internal fixation system was developed by absorbing the advantages of interlocking intramedullary nailing technique and biological bone grafting technique.In 1990, AO developed a new type of internal fixation product, the minimally invasive fixation system (LISS). Due to the use of an extracorporeal screw hole aimer, the damage to soft tissues during surgery is minimized. Self-drilling screws with angled fixation provide more reliable fixation. The minimally invasive fixation system (LISS) is suitable for the fixation of comminuted fractures of the distal femur and proximal tibia, and is particularly advantageous for osteoporotic patients and periprosthetic fractures. The LISS plate is designed with a shape that corresponds to the anatomical contours of the bone, i.e., the LISS-DF corresponds to the lateral anatomy of the lower end of the femur, and the LISS-PT to the upper end of the tibia.The position and angulation of the self-tapping or self-drilling Locking Head Screws (LHS) in the area of the bone ends of the LISS are precisely designed.The stability of the LISS is dependent on the screw-cementing plate. The stability of the LISS is dependent on the angular stability of the screw-plate combination after locking, while the locking screws in the end zone of the LISS not only optimally support and fixate the plate, but also do not cross the intercondylar groove or penetrate the patellofemoral joint surface. Ruedi et al. conceptualized the LISS as an internal fixator principle, understood in terms of an external fixation bracket, except that the fixation rods are very close to the bone surface, and the splint has no contact or compression with the bone surface, a feature that prevents any disruption of bone hemodynamics. Instead of long tubular fixation rods, long splints are used; strong self-tapping screws with threaded heads that lock tightly into the splints are used instead of the Schanz nails and protruding tightening clamps that are widely used in external fixation braces. The locking screws have better holding power in loose bone, making the LISS more suitable for periprosthetic and osteoporotic fracture fixation. each locking screw of the LISS plate can be screwed in percutaneously with the help of precise axial positioning of the screw holes, so that the plate is inserted percutaneously and the locking screws are fixed without exposing the fracture area, which is the principle of minimally invasive surgical technique. and the epiphyses mostly do not need to be replanted. Kregor summarized the clinical experience of LISS in the treatment of distal femur fracture and concluded that LISS has two basic advantages: firstly, the unique locking fixation is conducive to better fixation and maintenance of distal femur fracture after reduction; and secondly, the submuscular insertion of LISS reduces the complication and infection rate of the wound. SYNTHES LISS-DF and LISS-PT have 5 holes, 9 holes and 13 holes respectively, and are divided into left and right, each with 6 specifications.LISS-DF has 7 holes in the area of bone end with A, B, C, D, E, F, G, which is suitable for internal fixation of distal femur fracture including supracondylar fracture, intra-articular fracture of femur condyle, fracture of the distal part of the femur stem, etc. LISS-PT has 7 holes in the area of bone end with A, B, C, D, E, F and G. The LISS-PT has 5 holes, A, B, C, D, and E. It is suitable for proximal tibial fractures of AO subtypes 41A2, A3, C1, C2, C3, and all proximal types of AO42 fractures.The LISS can also be used in some bone diseases, osteoporotic fractures, or in the presence of a bone defect, and is suitable for the fracture of distal part of the femoral stem of the ipsilateral side after total hip arthroplasty or revision (long-stemmed), or for the fracture around the prosthesis of a knee arthroplasty. Periprosthetic fracture, etc. The concept of biological fixation technology has given rise to many internal fixation designs, among which LISS is a typical representative of “biomechanical fixation technology (BO)”.LISS is a new type of internal fixation system based on the principle of minimally invasive surgery, absorbing the advantages of interlocking intramedullary nailing and biological bone grafting technology, realizing minimally invasive and significantly improving the surgical treatment of femoral fractures. LISS is a special anatomical bone grafting plate for the lateral femoral condyle and the proximal tibia combined with a locking screw system. It consists of a plate, self-tapping monocortical and bicortical screws, a specialized percutaneous targeting external internal fixation device and a repositioner.