The current state of biomechanical analyses of the adult human femur: A systematic review

Abstract

Background: Biomechanical properties of adult femurs hold significant clinical and surgical relevance. However, a consolidated analysis of those material properties has not been established. Furthermore, the limitations of cadaveric studies and emergence of alternate methods of biomechanical femoral analyses, including synthetic femurs and modern technologies, warrant a comprehensive exploration.

Methods: Three databases were systematically reviewed for biomechanical studies of adult human femurs. Forty-two studies passed inclusion and exclusion criteria. These were categorized as cadaveric, composite, or modern/innovative, and results from these studies were aggregated and organized.

Findings: A total of 858 cadaveric specimens were evaluated, with a weighted average tensile modulus of 11.5 ± 1.08 GPa, compressive modulus of 683.3 ± 290.3 MPa, and ultimate stress of 2.24 ± 0.87 MPa. Analysis of 3D-printed and composite femurs exhibited substantial methodological heterogeneity, and aggregate data are presented herein. Modern technologies included finite-element analysis, x-ray/CT-based studies, fractal analysis, and scanning electron microscopy.

Conclusion: There exists substantial heterogeneity among femoral biomechanical studies. The standardized values derived from cadaveric studies provide baseline biomechanical values for surgical populations. The variety of surrogate femurs and modern technologies necessitate greater standardization in testing methodologies and outcome reporting. A validated and comprehensive library of biomechanical values would be beneficial for future studies.

Keywords: Biomechanics; Compressive strength; Femur; Finite element analysis; Tensile strength.