The Knee, ISSN: 1873-5800, Vol: 20, Issue: 4, Page: 232-5

Computer-assisted surgery: A teacher of TKAs

R. Iorio; D. Mazza; null G.Bolle; J. Conteduca; A. Redler; F. Conteduca; A. Ferretti


The hypothesis of this study is that computer-aided navigation experience could improve the ability to better place components in the coronal plane and to improve visual/spatial awareness based on the ability of navigation to provide instant feedback. The purpose of this study is to demonstrate the educational role of the navigation system to obtain a better alignment of the prosthetic components with standard instrumentation after a computer-aided navigation experience.

Materials and methods

One hundred fifty patients were operated by the same surgeon, with more than 5 years experience with TKA. They were equally divided in three groups: group A (operated with non-navigated technique by surgeon without computer-assisted experience); group B (operated with computer-assisted surgery by the same surgeon); group C (operated with non-navigated technique by the same surgeon after the computer-navigated experience).
We evaluated by full-length weight-bearing radiographs the overall alignment of the lower limb in the coronal plane. The optimum placement of the components was considered when the angle was within the limits of ± 3° varus/valgus on the coronal x-rays.
Comparison between groups was done using one-way ANOVA followed by post hoc Bonferroni test and Pearson chi-square statistics for proportions of optimum placement ( P < 0.05).


In the group A 34 patients (68%) had the optimum placement on the coronal x-rays; in the group B they were 46 (92%) and in the group 41 (82%).
The difference is statistically significant in comparing group A and Group B ( < 0.001), group A and group C ( P = 0.04), but not for group B and C ( P = 0.2).


We believe that the navigation system has an educational role to improve the ability of surgeon of positioning prosthetic components precisely in the coronal plane.

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