Related Experiment Video
Updated: May 6, 2026
The Use of Mixed Reality in Custom-Made Revision Hip Arthroplasty: A First Case Report
Published on: August 4, 2022
Accuracy of computer-assisted total knee arthroplasty related to extra-articular tibial deformities
Saran Tantavisut1, Aree Tanavalee, Srihatach Ngarmukos
1Department of Orthopaedics, Faculty of Medicine, Chulalongkorn University , Bangkok , Thailand.
Objective:
To compare the accuracy of postoperative mechanical alignment in computer-assisted total knee arthroplasties (CAS-TKA) related to various degrees of extra-articular tibial deformity.
Methods:
We performed CAS-TKA on 30 knee models in which extra-articular proximal tibial deformities were preset to have malalignments ranging from 30° of varus to 30° of valgus. The knees were assigned to two groups, designated Group A (knees with ≤ 15° preoperative malalignment) and Group B (knees with > 15° preoperative malalignment), and the postoperative mechanical alignment in the two groups was compared using a computer-assisted surgery (CAS) system. Resected bone pieces from the distal femurs and proximal tibias were measured with a digital Vernier caliper and the results compared with the CAS calculations to evaluate the execution accuracy of the bone resection.
Results:
There was no outlier in either group when a ± 3° deviation from neutral mechanical alignment was set as the acceptance criterion. Interestingly, Group B showed significantly more outliers when the acceptance criterion was a deviation of ± 2° (26.67%, p = 0.0317) or ± 1° (6.67%, p = 0.0007) from neutral alignment. There was no statistical difference between the groups in terms of the execution accuracy of the bone resection.
Discussion:
The CAS-TKA approach provided significantly less alignment accuracy in tibia with greater preoperative frontal deformity, despite there being no outliers beyond ± 3°.
