Is the Dynamic of the Pelvic Bone Altered After a Total Hip Replacement ? (DYPAMAT)

June 5, 2026 updated by: University Hospital, Brest

Total hip replacement is one of the most common surgical procedure in France. In 2010, an estimated 147 513 total hip procedures were performed. This number is constantly increasing.

Although it is common, it can lead to many complications. The intra-prosthetic luxation is the second one after aseptic loosening.

The luxation risk is multifactorial and depends on the relative orientation of femoral et acetabular components. This orientation is influenced by statics and dynamics parameters.

So far, the literature shows that only static parameters are considered by surgeons. Thus, in reference to Lewinneck publication, which states that the luxation risk is lower if the cup is oriented with 15° +/- 10° of anteversion and 40°+/- 10° of inclination with respect to the anterior pelvic plan (APP). Defined by the two anterosuperior iliacs spines and pubic symphysis.

However, this approach is only static and do not take into account the variations of pelvic plan orientation during everyday life.

To consider these variations of pelvic inclination, it is possible to measure the angle between APP and the horizontal (in lying position) or the vertical (in standing position) plan.

Several devices allow the measure of pelvic inclination but they all have important limits (EOS radiography, scanner or navigation). A new device has been developed in Brest to measure this inclination in several positions of the daily life.This software has already been tested in healthy volunteers and results demonstrate an excellent accuracy and reproducibility.

The goal of this study is to described the dynamic of the pelvic bone thanks to this ultrasound based device, and to assess the amount of variation induced by hip replacement procedures.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Terminated

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
15

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • France
      • Brest, France, 29200
        • CHRU de Brest

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion criteria :

  • Patient with primary or secondary hip arthritis, at stage II to III of the radiological classification of Tönnis and for whom total hip replacement is indicated by surgeon.
  • Signed consent
  • Patient beneficiary of a social security plan

Exclusion Criteria:

  • Patient Under 18
  • Patient Under protective measure (guardianship, curatorship) or unable to consent
  • Patient requiring revision THR
  • Patient with geographic mobility plan before the end of the follow-up
  • Symptomatic contralateral hip
  • Symptomatic dorsolumbar rachis
  • Pelvis or spine surgery planed during the follow-up
  • Pregnant or nursing woman

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Patient

All patients will have a clinical examination before surgery and another 3 months after surgery, each including :

  • A medical examination
  • 3 pelvic inclination measurements (1 sitting, 1 lying and 1 standing). These measurements will be done by ultrasound devices.
  • 2 EOS X-rays (1 standing and 1 sitting) of the lower limbs and spine
  • Harris hip score
  • Pain quantification thanks to an EVA scale
  • hand-ground distance
Other: Pelvic inclination measurement
Ultra-sound based measurements of the pelvic inclination lying, standing and seating position. EOX X-ray in seating position.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Variation of the pelvic incidence
Time Frame: Day 0 - Month 3
The main evaluation criterion is the variation of the pelvic incidence between pre- and post-operative total hip replacements
Day 0 - Month 3

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Analysis of the correlation between the variation in pelvic incidence while sitting, standing and lying down and the implant settings
Time Frame: Day 0 - Month 3
Assessed by EOS X-Ray.
Day 0 - Month 3
Analysis of the correlation between variation in pelvic incidence while sitting, standing and lying down and clinical parameters (Harris hip score)
Time Frame: Day 0 - Month 3
Clinical examination (Harris hip score) will be performed at day 0 and month 3.
Day 0 - Month 3
Analysis of the correlation between variation in pelvic incidence while sitting, standing and lying down and clinical parameters (EVA)
Time Frame: Day 0 - Month 3
Clinical examination (EVA) will be performed at day 0 and month 3.
Day 0 - Month 3
Analysis of the correlation between variation in pelvic incidence while sitting, standing and lying down and clinical parameters (Hand-ground distance)
Time Frame: Day 0 - Month 3
Clinical examination (Hand-ground distance) will be performed at day 0 and month 3.
Day 0 - Month 3

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University Hospital, Brest

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
February 2, 2021

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
February 26, 2022

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
February 26, 2022

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
October 2, 2020

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 13, 2020

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
October 14, 2020

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
June 8, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 5, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
June 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 29BRC20.0120

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

All collected data that underlie results in a publication.

IPD Sharing Time Frame

Data will be available beginning three years and ending fifteen years following the final study report completion.

IPD Sharing Access Criteria

Data access request will be reviewed by the internal committee of Brest University Hospital. Requestor will be required to sign and complete a data access agreement.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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