240 patients scheduled for total knee arthroplasty were randomized to undergo the procedure with either image-free navigation or standard instrumentation. The purpose of this study was to investigate whether TKA performed by experienced surgeons via image-free navigation would be associated with significantly improved prosthesis/limb alignment and functional scores. Results demonstrated that patients in the image-free navigation group had significantly improved pain, function sub scores and alignment values, as a well as a significantly decreased number of knee alignment outliers postoperatively.