Related Experiment Video
Updated: May 8, 2026
In Vitro Application of a Wireless Sensor in Flexion-Extension Gap Balance of Unicompartmental Knee Arthroplasty
Published on: May 5, 2023
Optimal tibial component size set in unicompartmental knee arthroplasty for Chinese patients and comparison with
Yandong Sun1,2, Diyang Zou1, Huarui Shen3
1School of Biomedical Engineering & Med-X Research Institute, Engineering Research Center of Digital Medicine and Clinical Translation, Shanghai Jiao Tong University, Ministry of Education, Shanghai, 200030, China.
Background:
The coverage of the tibial component affects the success of unicompartmental knee arthroplasty (UKA). However, most UKA implants used in China are designed based on the knee morphology of Caucasian populations. The purposes of this study were to (1) provide accurate anatomical parameters of the medial tibial plateau in the Chinese population, (2) define an optimal set of UKA tibial component sizes based on anthropometric data, and (3) compare the tibial coverage of several commercially available UKA tibial designs with that of the suggested optimal tibial component.
Methods:
A standard virtual tibial resection was performed on 620 healthy knees using three-dimensional (3D) reconstructed models derived from computed tomography (CT) scans. The anteroposterior (AP) and mediolateral (ML) dimensions of the medial tibial plateau were measured. For implant sizing optimization, priority was given to the implant size that resulted in ≤ 1 mm of ML overhang; among those satisfying this criterion, the size with the smallest AP mismatch was selected. We designed sets of tibial component sizes (containing 6, 8, and 10 sizes) and optimized their configurations using a cost function defined as the weighted sum of AP and ML errors to evaluate prosthesis coverage. Commercially available UKA tibial implant designs were included to compare their mismatch errors with those of the suggested optimal tibial component.
Results:
In the conventional designs, the highest and lowest percentages of best-fit (within the range of -2 mm to 1 mm) in the mediolateral (ML) dimension were observed for the Zimmer Unicompartmental High Flex Knee (ZUK)/Journey (95.0%) and the Sled (41.3%), respectively. In the anteroposterior (AP) dimension, the highest and lowest percentages were found in the Oxford (49.5%) and the Journey (15.3%). In the three optimal designs, the percentages of best-fit in the ML dimension were 83.1%, 86.0%, and 88.1% for the 6-, 8-, and 10-size sets, respectively. In the AP dimension, the corresponding percentages were 55.5%, 72.6%, and 77.1%.
Conclusion:
Most commercially available UKA tibial component size sets cannot fully accommodate the anatomical variation of the tibia in the Chinese population. Ethnic-specific designs similar to the optimal designs proposed in this study are needed.