89 patients (102 knees) requiring total knee arthroplasty were randomized to receive either navigation-assisted less invasive total knee arthroplasty (NA-LIS TKA) or conventional total knee arthroplasty (CON TKA). Range of motion, ability to perform 90 degree flexion and straight leg raise, extension lags, and pain were measured throughout the course of the study. The NA-LIS TKA group had better outcome scores than the CON TKA group during the early postoperative period, but by the end of the two week study, there was no significant difference in outcome measurements between the NA-LIS TKA and CON TKA groups.