Function-orientated structural analysis of the proximal human femur

Area of Science:

• Biomechanics
• Orthopedic Surgery
• Human Anatomy

Background:

• Friedrich Pauwels' biomechanical model of the proximal femur posits tensile forces at the greater trochanter.
• Recent examination of abductor muscle insertions suggests local compression stress instead.

Purpose of the Study:

• To investigate whether the internal architecture of the proximal femur supports tensile or compressive stress at the greater trochanter.
• To evaluate Pauwels' biomechanical model against empirical evidence from trabecular bone structure.

Main Methods:

• Analysis of trabecular bone structure in 10 human cadaver femora using CT scans.
• Utilized architectural software Allplan(R) for detailed trabecular analysis.
• Measured orientation angles between medial, trochanteric, and arcuate trabecular systems.

Main Results:

• Medial and trochanteric trabecular systems are oriented nearly perpendicular (mean 90.7° and 84.9°) to the arcuate system.
• Medial trabecular system is oriented nearly perpendicular (mean 94.7°) to the femoral head epiphysis.
• Trabecular architecture aligns with compressive stress patterns.

Conclusions:

• The internal architecture of the proximal femur strongly supports compressive stress at the greater trochanter.
• Pauwels' hypothesis of predominant tensile force from abductor muscles is unlikely.
• Trabecular bone orientation reflects functional adaptation to mechanical loads.