The treatment of knee joint injuries has seen a marked development. Arthroscopy is standard for diagnostic purposes, for meniscus resection and meniscus refixation. Anterior cruciate ligament reconstruction may be performed mini-invasive by arthroscopic or mini-open technique with comparable result. Drill guide systems and fixation techniques allow for precise and stable graft placement. Posterior cruciate ligament surgery is presently undergoing a similar process of optimisation as ACL surgery has some years ago. The surgical trauma of intraarticular fracture reconstruction was also reduced significantly. Retrograde nailing, percutaneous plating and specific exposures to distal femur and proximal tibia fractures have been established. Percutaneous osteosynthesis controlled by arthroscopy or fluoroscopy is widely used for B-fractures of the tibial plateau. Injectable bone mineral cement adds to reduced trauma of surgical treatment of these fractures. Mini-invasive knee surgery will develop rapidly in the coming years.