Computer-assisted alignment system for tibial component placement in total knee replacement: a radiological study.

In total knee replacement (TKR), regarding tibial component positioning, almost all implants offer both an intramedullary and an extramedullary alignment guide, leaving it up to the surgeon which guide to use. However, early failure in TKR can be caused by incorrect positioning or orientation with poor limb alignment. Recently computer-based alignment systems have been developed to help the surgeon to overcome these complications. The Authors retrospectively analysed their experience using a computer-based CT-free alignment system. They assessed the radiological alignment of the tibial components in 38 computer-assisted TKR 6 months after surgery. The frontal tibial component angle (FTC) and the sagittal orientation of the tibial component (slope) were evaluated 6 months after the operation. The results were compared to those achieved with traditional alignment systems. The surgical time was statistically longer in the computer-assisted group but in this group all the tibial components were aligned within 4 degrees of all the ideal measurements in both frontal and sagittal planes.