AUTHOR=Yuwen Peizhi , Sun Weiyi , Guo Jialiang , Chang Wenli , Wei Ning , Wang Haicheng , Ding Kai , Chen Wei , Zhang Yingze TITLE=Femoral–tibial contact stresses on fixed rotational femur models JOURNAL=Frontiers in Surgery VOLUME=9 YEAR=2023 URL=https://www.frontiersin.org/journals/surgery/articles/10.3389/fsurg.2022.1016707 DOI=10.3389/fsurg.2022.1016707 ISSN=2296-875X ABSTRACT=Objectives

This study aims to quantitatively evaluate the femoral–tibial contact pressure on the knee under certain malrotaional degrees.

Methods

Femoral–tibial contact pressure was carried out on 14 fixed rotational knee models under 200/400/600 N vertical load using ultra-low-pressure sensitive film technology, rotation angles including neutral position (0°, anatomically reduced), 5°, 10°, and 15° internally and externally. Data were collected and analyzed with SPSS software.

Results

There are significant statistical differences between the medial contact pressure among rotational deformities (including neutral position) (P < 0.01), the increase in the degree of fixed internal malrotation of the femur resulted in a linear increase in the medial femoral–tibial contact pressures (P < 0.05) under 200/400/600 N vertical load, while increase in the degree of fixed external malrotation resulted in a linear decrease (P < 0.05). Except the 200 N compression, we can't find significant differences in lateral contact pressures (P > 0.05). In the comparison of medial to lateral contact pressures, no statistically significant differences were found in neutral and 5° internal rotation under 200/400 N, neutral, 5° internal rotation, and 15° external rotation under 600 N. In contrast, medial contact pressures were higher than lateral at other angles (P < 0.05).

Conclusion

Obvious contact pressure changes were observed in rotatory femur. Doctors should detect rotational deformity as much as possible during operation and perform anatomical reduction. For patients with residual rotational deformities, indication of osteotomy should not be too broad.