Advances in surgical techniques and equipment have recently encouraged the use of minimal incision surgery (MIS) in total knee arthroplasty (TKA). However several complications have been reported following MIS, among which, early loosening is one of the most serious issues. We report two cases that experienced early loosening of the tibial component within three months of surgery, and received revision surgery within three years of primary MIS TKA. The cases were compared with 50 other cases which received MIS TKAs by the same technique, and it was hypothesized the failures in the two relatively young patients may have been caused by virus implantation of the tibiae component and a large bony cut in the proximal tibia, possibly as a result of limited working space during surgeries.