Total knee replacement is increasing in number due to increased life expectancy and improved implants. [figure: see text] Degenerative changes (arthritis) and joint destruction based on polyarthritis and posttraumatic deformities are the common indications. There are basically four modes for knee replacement: Unicompartimental prosthesis, non-constrained, semi-constrained (posterior stabilized) and constrained total knee arthroplasty. Of major importance in knee alloarthoplasty are restitution of the correct limb axis, sufficient lateral ligaments and the restoration of the patellofemoral joint. Therefore particularly in cases with deformities an extensive soft tissue release is mandatory. A meticulous operative technique and versatile implants lead to good clinical outcome. Possible complications are still septic and aseptic implant loosening as well as wound infections.