Assessment of Femoral Failure Load and Fracture Risk in Rare Bone Disorders Using MEKANOS Tool. Case Study of Fibrous Dysplasia of Bone/McCune Albright Syndrome (MEKADYS)

Assessment of Femoral Failure Load and Fracture Risk in Rare Bone Disorders Using MEKANOS Tool. Case Study of Fibrous Dysplasia of Bone/McCune Albright Syndrome. MEKADYS Study

The issue of rare diseases has become a public health priority. In France, a national plan for rare diseases was published in 2004. It leads to the creation and certification of numerous Rare Disease Reference Centers by the French National Authority for Health (Haute Autorité de Santé).

Our Fibrous Dysplasia Reference Center has been certified since 2006. However, evaluating the mechanical strength and fracture risk of fibrous dysplasia lesions remains a major unresolved challenge for clinicians. Improving the assessment of fracture risk therefore represents a key clinical objective.

Study Overview

• Status: Active, not recruiting
• Conditions: Fibrous Dysplasia/McCune-Albright Syndrome
• Intervention / Treatment: Other: Application of MEKANOS tool to CT scans

• Study Type: Observational
• Enrollment (Estimated): 20

Contacts and Locations

Study Locations

• France
  • Lyon
    • Lyon, Lyon, France, 69003
      • Edouard Herriot Hospital - rheumatology

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Clinical data issued from Easily HYBRID DF Database, and CT images of long bones acquired during routine clinical care and retrieved from the HCL imaging..

Description

Inclusion Criteria:

• Adults with Fibrous Dysplasia (FD) of the bone or McCune-Albright Syndrome (MAS);
• who have received care at the center through outpatient consultation, multidisciplinary evaluation, or hospitalization;
• whose diagnosis was confirmed by an expert physician from the reference center based on a combination of clinical, biochemical, and radiological criteria, in accordance with the recommendations of the international FD/MAS consortium (Javaid MK et al., Orphanet J Rare Dis. 2019);
• for whom a histological confirmation was obtained in cases of diagnostic uncertainty;
• no objection to data collection

Exclusion Criteria:

• - CT scan with implanted material on the femur,
• Individuals under legal protection measures

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

CT scans of Patients with femoral fibrous dysplasia lesions identified in the Easily HYBRID DF datab; Application of MEKANOS tool to CT scans.

Other: Application of MEKANOS tool to CT scans; MEKANOS tool is an algorithm that automatically segments femurs from clinical CT scans, generates a numerical model, and performs a numerical simulation of single leg stance loading on these femurs. The tool is developed within INSERM unit 1033 and is currently available only in the laboratory. Input data consist of CT imaging (DICOM format) and retrospective clinical data. The output is the failure load expressed in Newtons.Interpretation of the results involves determining fracture risk based on the failure load (pathological bone versus healthy bone), and then integrating patient size and weight. CT Scans are issued from the HCL PACS, and clinical data issued from Easily Hybrid DF database.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Tool X	Obtaining an image suitable for processing with tool X in order to compute failure strength through numerical simulation (i.e., adequate bone segmentation and a correctly implemented numerical model with appropriate boundary conditions).	CT scans of Patients with femoral fibrous dysplasia lesions performed from January 2002 until 9 March 2025.

Collaborators and Investigators

• Sponsor: Hospices Civils de Lyon

Study record dates

Study Major Dates

• Study Start (Actual): March 10, 2025
• Primary Completion (Actual): March 10, 2026
• Study Completion (Estimated): March 10, 2027

Study Registration Dates

• First Submitted: February 12, 2026
• First Submitted That Met QC Criteria: March 30, 2026
• First Posted (Actual): April 2, 2026

Study Record Updates

• Last Update Posted (Actual): April 2, 2026
• Last Update Submitted That Met QC Criteria: March 30, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: bone disease; Fibrous dysplasia; McCune Albright; MEKANOS tool; MAS-DF; fracture risk in rare bone disease
• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Osteochondrodysplasias; Bone Diseases, Developmental; Bone Diseases; Fibrous Dysplasia of Bone; Fibrous Dysplasia, Polyostotic
• Other Study ID Numbers: 69HCL25_0493; 25-5106 (Other Identifier: HCL)

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No