Triangular Mechanical Structure of the Proximal Femur

Area of Science:

• Orthopedic biomechanics
• Bone structure analysis
• Finite element analysis

Background:

• The mechanical properties of the proximal femur are crucial for understanding and treating proximal femoral fractures.
• Clinical surgical treatment and instrument design can benefit from knowledge of the proximal femur's mechanical structure.

Purpose of the Study:

• To analyze and verify the mechanical structure of the proximal femur.
• To investigate the relationship between bone mass distribution and stress concentration in the proximal femur.

Main Methods:

• Computed tomography (CT) scans of 375 patients with intertrochanteric fractures were analyzed.
• Cortical and medullary cavity parameters were measured at eight planes.
• Six proximal femoral finite element models were constructed and subjected to force load analysis using Abaqus to determine von Mises stress distribution.

Main Results:

• Higher cortical thickness and mean density were observed in the upper, lower, medial, and lateral walls compared to anterior and posterior walls.
• Upper-lower diameter length increased distally, while medial-lateral diameter length decreased distally.
• Von Mises stress was concentrated on the upper/lower walls of the femoral neck and medial/lateral walls of the femoral trochanteric region, indicating these areas bear the main stress.

Conclusions:

• The proximal femur possesses a triangular high-modulus bone distribution that bears the primary stress.
• This triangular mechanical structure offers valuable guidance for surgical strategies and instrument design in treating proximal femoral fractures.