This study aims to compare the clinical results of patella resurfacing or not under subvastus approach in total knee arthroplasty. Even though the excellent results of total knee arthroplasty(TKA), there is persistent controversy over whether or not to replace the patella. Anterior knee pain continued to be a unsolved problem of TKA patients. Some surgeons always performed patella resurfacing during total knee arthroplasty but the others didn't do that. It's up to surgeon's preference. There were several studies of patellar resurfacing or not in TKA. But previous studies almost have been done under other approach, not a subvastus approach.