Modern abbreviated computer navigation of the femur reduces blood loss in total knee arthroplasty

Computer assisted surgery (CAS) optimizes component position in total knee arthroplasty (TKA), yet effects specifically on blood loss are less known. This study purpose was to determine whether a modern abbreviated CAS protocol would reduce blood loss in TKA compared to conventional instrumentation. One hundred consecutive TKAs were retrospectively reviewed comparing abbreviated CAS versus conventional IM instrumentation. Blood loss was determined using drain output, change in hemoglobin, and calculated blood loss. The CAS group demonstrated less hourly drain output (P = 0.02), hemoglobin change (P = 0.001), and estimated blood loss (P = 0.001) versus conventional instrumentation. With proven advantages of accurate component placement and improved functional outcome after TKA, CAS provides additional value by reducing blood loss in TKA.