Total Hip Arthroplasty Instability and Lumbo-pelvic Kinematics: EOS Imaging Assessment of Variation in Spinal and Pelvic Parameters From Standing to Sitting

Study Overview
=================
Brief Summary
-----------------
The authors hypothesize that a pelvic kinematic disorder, demonstrated by a significant decrease in sacral slope, is associated with the risk of instability of total hip prosthesis, the sacral slope being measured by an EOS imaging system during the transition to sitting in unstable patients versus patients with no history of instability.

Official Title
-----------------
Total Hip Arthroplasty Instability and Lumbo-pelvic Kinematics: EOS Imaging Assessment of Variation in Spinal and Pelvic Parameters From Standing to Sitting

Conditions
-----------------
Hip Fractures

Intervention / Treatment
-----------------
* Other: EOS imagery


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: The patient must have given their free and informed consent and signed the consent form The patient must be a member or beneficiary of a health insurance plan The patient must be at least 18 years old and less than 85 years old Patient has a conventional first intention total hip arthroplasty (not dual mobility) by posterior approach Case patients have at least one previous episode of prosthetic dislocation repaired with surgery Control patients have no previous episode of prosthetic dislocation with more than 2 year since initial intervention Exclusion Criteria: The subject is participating in a category 1 interventional study, or is in a period of exclusion determined by a previous study The subject refuses to sign the consent It is impossible to give the subject informed information The patient is under safeguard of justice or state guardianship Patient is pregnant, parturient or breastfeeding Patient with lumbar instrumentation Patient with severe dementia (Mini Mental State Examination < 10) Patient with American Society of Anesthesiologists score ≥ 4 Patient experience multiple falls Patient requiring early revision surgery (<15 days postoperatively Patient with obvious implant positioning error on an X-ray of the pelvis. Patient with dislocation of traumatic origin (significant kinetic trauma)

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 85 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Other
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Patients with previous prothesis instability<br> | Other: EOS imagery<br>* Whole body EOS imaging in seated and standing position<br>|
| Other: Patients without prothesis instability<br> | Other: EOS imagery<br>* Whole body EOS imaging in seated and standing position<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Sacral slope between standing to sitting difference between groups | Sacral slope between standing to sitting difference between groups | Day 0 | 
| Rate of type 1 pelvic kinematic disorder between groups | Measured by sacral slope difference from standing to seated position < 12°. | Day 0 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Lumbar lordosis between standing and seating between groups | degree | Day 0 | 
| Femoroacetabular flexion between standing and seating between groups | degree | Day 0 | 
| Lewinnek plane (Anterior pelvic plane) between standing and seating between groups | degree | Day 0 | 
| Pelvic version between standing and seating between groups | degree | Day 0 | 
| Classification of patients' pelvic kinematic disorder (Type 1 or 2) | Type 1 = Difference in sacral slope between standing and seated position < 12° Type 2 = pelvic version < 20° standing | Day 0 | 
| Classification of patients according to pelvic incidence | Presence/absence | Day 0 | 
| Classification of patients according to sacral slope | Presence/absence | Day 0 | 
| Classification of patients according to sagittal imbalance | Presence/absence of: Sagittal Vertical Axis > 50 mm; Spino-Sacral Angle < 127° | Day 0 | 
| Evolution of acetabular positioning (anteversion and inclination in degree) from standing to sitting | Degree | Day 0 |