Femoral-tibial contact stresses on fixed rotational femur models

Peizhi Yuwen; Weiyi Sun; Jialiang Guo; Wenli Chang; Ning Wei; Haicheng Wang; Kai Ding; Wei Chen; Yingze Zhang

doi:10.3389/fsurg.2022.1016707

Femoral-tibial contact stresses on fixed rotational femur models

Front Surg. 2023 Jan 6:9:1016707. doi: 10.3389/fsurg.2022.1016707. eCollection 2022.

Authors

Peizhi Yuwen¹, Weiyi Sun¹, Jialiang Guo¹, Wenli Chang², Ning Wei³, Haicheng Wang¹, Kai Ding¹, Wei Chen^{1

4

5

6}, Yingze Zhang^{1

4

5

6}

Affiliations

¹ Orthopaedic Research Institute of Hebei Province, Hebei Medical University Third Affiliated Hospital, Shijiazhuang, China.
² Department of Hand Surgery, Cangzhou Hospital of Integrated TCM-WM of Hebei, Cangzhou, China.
³ Department of Orthopedic Surgery, Chinese People's Liberation Army Joint Security Force 980th Hospital, Shijiazhuang, China.
⁴ Key Laboratory of Biomechanics of Hebei Province, the Third Hospital of Hebei Medical University, Shijiazhuang, China.
⁵ Trauma Emergency Center, the Third Hospital of Hebei Medical University, Shijiazhuang, China.
⁶ NHC Key Laboratory of Intelligent Orthopeadic Equipment, the Third Hospital of Hebei Medical University, Shijiazhuang, China.

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.

Keywords: biomechanics; contact pressure; external rotation; fracture; internal rotation; knee.