A Computer Navigation System Analysis of the Accuracy of the Extramedullary (Tibial) Alignment Technique in Total Knee Arthroplasty (TKA)

In total knee arthroplasty, mechanical alignment guides have improved the accuracy of implant alignment, but errors are not uncommon. In the present study, an image-free computer-assisted navigation system was used to analyse the accuracy of an extramedullary (tibial) alignment system, which is based on predetermined, fixed anatomical landmarks. Comparisons were made between two surgeons, with different levels of competency in order to determine if experience affected the accuracy of extramedullary tibial jig placement, in either the coronal and sagittal planes or both planes. The results showed that the accuracy of the extramedullary tibial alignment system, in the coronal plane (in up to 80-87% of cases) was much better than for posterior slope, and sagittal plane. Surgeon experience was not a significant factor.