Glenoid track evaluation by a validated finite-element shoulder numerical model.

Area of Science:

• Biomechanics
• Computational modeling
• Orthopedics

Background:

• Traditional methods for defining the glenoid track do not fully account for physiological joint forces.
• These forces can influence the accuracy of glenoid track measurements.
• Finite element analysis offers a more realistic simulation of joint forces.

Purpose of the Study:

• To evaluate the glenoid track using a finite element numerical model of the shoulder.
• To investigate the impact of joint forces on glenoid track dimensions.

Main Methods:

• Developed a finite element model of the shoulder including bones, cartilage, and rotator cuff muscles.
• Utilized an algorithm to balance arm weight and calculate muscle, wrapping, and reaction forces.
• Assessed glenoid track dimensions at various abduction angles (60°, 90°, 120°) with and without applied forces.

Main Results:

• The finite element model's anatomy and physiology were validated.
• Glenoid track dimensions varied based on applied forces and abduction angles, with values ranging from 71% to 104% of glenoid length.
• Yamamoto's and Omori's parameters showed differences in glenoid track measurements before and after force application.

Conclusions:

• The developed numerical model is effective for evaluating shoulder articular contact.
• Articular contact analysis supports the glenoid track concept and suggests its evolution.
• Glenohumeral joint forces are critical factors influencing glenoid track measurements and must be considered.