Total knee replacement surgery is usually performed under a general anesthetic, and takes around two hours. An incision is made to expose the kneecap, which is then pushed aside so that your surgeon can access the damaged ends of the thigh and shin bone. The damaged bones are then removed, and a prosthesis is then modelled on the measurements of the removed bone. The ends of the thigh and shin bone are replaced using the new metal fittings, and set in place using bone cement (sometimes this is not necessary). A piece of plastic is then inserted between the two metal ends, acting as substitute cartilage, and helping to reduce any friction. The incision is then closed using stitches or surgical clips, and finally bandaged (sometimes with a splint). Sometimes a tube may be left in the knee to allow fluids to drain out, but will be taken out around 48 hours following surgery.