After knee replacement surgery, patients may asbe concerned about the length of their operative leg compared to their non-surgical leg. Well, a knee replacement surgery there’s often a correction of a curvature or angle of the leg. This curvature often involves both knees. When one of the knees is straightened it actually does make the leg longer. This can actually be present until the other knee is fixed. If the other knee is well, there’s less of a chance of perceiving that one leg is longer than the other. The length of your leg and your knee was determined when you are fully grown as a teenager and is determined by the ligaments on the sides of your knee. While it may be possible to lengthen a hip replacement surgery, it is not possible to lengthen your knee.