Finite element modelling and experimental validation of a total implanted shoulder joint

Area of Science:

• Biomechanics
• Orthopedic Surgery
• Finite Element Analysis

Background:

• Replicating total shoulder arthroplasty in laboratory settings is challenging due to complex joint geometry.
• Existing numerical models for implanted shoulder joints often lack experimental validation.
• Accurate simulation requires robust models that closely mimic experimental setups.

Purpose of the Study:

• To develop and validate a finite element model of an implanted total shoulder joint.
• To compare numerical predictions with experimental strain measurements for model verification.
• To establish a reliable method for simulating shoulder joint biomechanics.

Main Methods:

• A non-cemented Anatomical Comprehensive© Total Shoulder System was implanted in composite bone models.
• A corresponding finite element model was created, incorporating shoulder abduction muscles and identical boundary conditions.
• Strain gauge rosettes measured experimental strains at 90° abduction for comparison with model outputs.

Main Results:

• The finite element model demonstrated adequate replication of the experimental setup.
• Linear regression analysis showed a high correlation (R²=0.945) between numerical and experimental strain data.
• A root-mean-square error of 35 µε indicated good agreement, with observed posterior-to-anterior load distribution shifts.

Conclusions:

• Experimental methods successfully validated the developed finite element model for shoulder arthroplasty.
• Strain gauge measurements are effective for the numerical-experimental validation of bone joint models.
• The validated model provides a reliable tool for investigating implanted shoulder joint biomechanics.