Radiologist-Integrated Finite Element Framework for Acromial Stress in Reverse Shoulder Arthroplasty
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- This is an observational study: the protocol does not assign a study treatment.
- Who it may be relevant to
- Registry conditions: Rotator Cuff Injuries, Shoulder Fractures. Basic parameters: 60 years — 80 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Italy
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Official title
From Clinical Grading to Mechanical Vulnerability: A Radiologist-Integrated Parametric Finite Element Study of Progressive Cuff Deficiency and Acromial Overload in Reverse Shoulder Arthroplasty
Overview
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 will then be analyzed in anatomically defined acromial zones (Levy zones I-III).
Detailed description
Background and Rationale. Acromial stress fracture is a recognised complication following reverse shoulder arthroplasty (RSA), with a clinically relevant incidence reported in prospective cohorts. The mechanical link between RSA-induced load redistribution and acromial fracture localisation remains incompletely characterised, and no validated preoperative tool currently exists to stratify acromial fracture risk on a patient-specific basis. This study addresses that gap by integrating musculoskeletal radiology grading with subject-specific finite element (FE) modelling within a single prospective pipeline.
Study Design. A prospective single-centre observational cohort of consecutive elective RSA candidates will be enrolled. Each participant will undergo high-resolution preoperative imaging consisting of computed tomography (voxel ≤1 mm) for cortical bone reconstruction and 1.5T or 3T magnetic resonance imaging for soft-tissue and rotator cuff assessment.
Radiologist Grading and Cuff Deficiency Index. Rotator cuff integrity will be graded by a senior musculoskeletal radiologist using the Goutallier classification for fatty infiltration. From these grades, a continuous Cuff Deficiency Index (CDI) will be derived as a quantitative descriptor of cuff functional capacity. The CDI will be used as a direct biomechanical input to scale the deltoid force estimates applied to the FE model.
Finite Element Pipeline. Patient-specific finite element models will be constructed from the segmented imaging data. Cortical bone will be assigned heterogeneous Hounsfield-mapped material properties, deltoid muscle anatomy will be reconstructed from MRI, and physiological as well as RSA-specific loading scenarios will be simulated using FEBio. Mesh convergence and boundary-condition sensitivity will be verified for each subject.
Outcome Assessment. The primary outcome is the regional 95th-percentile von Mises stress within acromial regions of interest corresponding to Levy zones I-III, evaluated at six months post-surgery. Stress-based and morphometric parameters will be correlated with postoperative radiographic outcomes assessed at the same six-month follow-up.
Expected Contribution. By coupling radiologist-graded clinical input with patient-specific FE modelling, this study aims to establish the feasibility of a prospective framework for preoperative acromial stress assessment in RSA candidates.
Primary outcome measures
- Regional von Mises stress within acromial Levy zones [Time frame: 6 months post-surgery]
Eligibility criteria
Inclusion criteria
- Adult patients (60-80 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
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Observational model
- Cohort
Study locations
Italy · 1 center
- University of Molise — Campobasso
Publications
- Levy JC, Anderson C, Samson A. Classification of postoperative acromial fractures following reverse shoulder arthroplasty. J Bone Joint Surg Am. 2013 Aug 7;95(15):e104. doi: 10.2106/JBJS.K.01516. PMID 23925750
Identifiers
NCT: NCT07545707 · UniMol-RSA-26