The LISS DF (less invasive stabilisation system) is a new internal fixator for the operative treatment of distal femur fractures following the principles of minimally invasive surgery. The fixation of the implant is based on screws providing angular stability, which are inserted percutaneously guided by an aiming device. A large exposure of the fracture zone is not necessary. Between December 1996 and November 1998 a multicentre study were defined including finally 112 patients with 116 distal femur fractures treated with a LISS system. A follow up rate of 93% could be achieved, showing a fractures consolidation in 96% of all cases after 12 months. The results of the study showed a low rate of secondary bone grafting. The LISS system is a secure device for the treatment of all distal femur fractures including complex articular fractures types.