When performing total knee replacement surgery, the surgeon has a choice as to which type of surgical technique to use. The standard technique at the Royal Infirmary in Edinburgh is the so-called 'medial parapatellar' exposure. And alternative and more recently introduced technique is the 'Mid-vastus approach' in which the surgeon will cut through less of the muscle at the front of the leg. In this study we compare the two surgical techniques in a so-called randomized trial. This means that we put people randomly into two groups, one group will receive surgery with the 'Mid-vastus approach' and the other group the surgery with the 'Medial parapatellar approach'. It is hypothesized that people who receive the Mid-vastus approach recover quicker and have a better short-term functional outcome than people who receive the 'Medial parapatellar approach'.