The surgery takes about 1-1/2 hours and the patient is usually hospitalized only overnight. (One to two days in some cases). The procedure involves restoring about 1/3 of the joint surface with approximately a 3 - 6 inch incision. Due to the small amount of bone that is resected to implant the device, there is a maximum preservation of tissue, the ligaments are retained and the remaining knee compartments remain intact.