Total Knee Replacement with iASSIST Navigation System

Background/Purpose The iASSIST system is a novel navigation system for total knee replacement. It is based on accelerometers built within electronic pods attached to the instruments within the operative field. The objective of this study was to compare the accuracy of iASSIST navigation with that of the conventional alignment technique. Methods A total of 91 patients (92 knees) retrospectively matched for age, gender, preoperative range of motion, and lower limb deformity underwent total knee replacement using iASSIST navigation (45 patients, 46 knees) or conventional instrumentation (46 patients, 46 knees). Operative time and radiological alignments were compared. Results The use of iASSIST navigation resulted in fewer outliners (as defined by >3° deviation from the neutral mechanical axis) in lower limb alignment. Operative time with iASSIST navigation was not longer than that using conventional instruments. Conclusion iASSIST navigation reduces the incidence of lower limb malalignment without adding extra time to the procedure.