Radiologist-Integrated Finite Element Framework for Acromial Stress in Reverse Shoulder Arthroplasty

The current prospective single-center study is designed to examine an approach that utilizes both high-resolution CT and MRI scans, coupled with customized finite element modelling to analyze the stress placed on the acromion of patients who have undergone RSA surgery. The degree of rotator cuff deficiency will be assessed using Goutallier classification and quantified as Cuff Deficiency Index (CDI), which directly provides biomechanical information for calculating deltoid forces used in finite element analysis. Von Mises stresses in specific acromion zones defined by Levy et al. will then be analyzed.

Inclusion Criteria: * Adult patients (60-85 years) with cuff tear arthropathy (Hamada grade 3 or above, Walch glenoid B/C) scheduled for primary unilateral reverse shoulder arthroplasty * Availability of preoperative high-resolution CT (voxel 1 mm or less) and 1.5T/3T MRI * Written informed consent for prospective use of anonymised data Exclusion Criteria: * Revision RSA or history of prior shoulder prosthetic complications * Uncorrectable imaging artefacts * Post-RSA follow-up shorter than 6 months