Postoperative Painful Chronicization After Knee Replacement Surgery : Exploratory Study of BDNF's Kinetics

Study Overview
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Brief Summary
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Chronic pain is an extremely disabling disease. It is a major public health problem due to the lack of effective therapy. Chronic postoperative pain (CPOP) is defined by a painful symptomatology in the operated area unrelated to previous pain, present for more than 3 months, and without any link to surgical complication. The prevalence of chronicization of postoperative pain is 30% after total knee arthroplasty. Identification of clinical, biological and psychological profiles are crucial to prevent CPOP. A biologic factor, Brain Derived Neurotrophic Factor (BDNF) produced by a variety of cells is a key regulator of neuroplasticity. BDNF is increasingly studied in the mechanisms of cerebral sensitization and pain chronicization. The role of BDNF in pain of patients remains to be explored in a prospective study. The aim of this observational study is to compare the kinetics of BDNF after total knee arthroplasty in patients with and without CPOP. Patients will be included in the study at the preanesthetic consultation. Serum BDNF levels will be measured preoperatively, 48h postoperatively, 3 and 6 months after surgery.

Official Title
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Postoperative Painful Chronicization After Knee Replacement Surgery : Exploratory Study of BDNF's Kinetics

Conditions
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Total Knee Arthroplasty, Chronic Postoperative Pain

Intervention / Treatment
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* Diagnostic Test: blood test


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Social security affiliation Adult patients Signed informed consent Score ASA (American Society of Anesthesiology) 1-3 Total knee arthroplasty Exclusion Criteria: Patient unable to exercise consent Pregnant women Vulnerable people Patients not included in the postoperative rehabilitation program Patients unable to complete the pain assessment questionnaires Chronic pain patients (other than knee arthrosis) Neuropathic pain patients (beforehand) Inflammatory diseases, progressive cancer, sepsis, immunosuppression known

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Interventional Model Description: Prospective study to analyze perioperative blood samples in patient after knee replacement surgery. Patients will be included in the study at the pre-anesthetic consultation. Serum BDNF levels will be measured preoperatively, 48h postoperatively, 3 and 6 months after surgery.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Total knee arthroplasty<br>patient operated for a total knee arthroplasty | Diagnostic Test: blood test<br>* blood test to explore BDNF level<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| BDNF level | assessed by ELISA technique | preoperative to 6 months after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain level | evaluated by Visual Analog Scale (VAS) | preoperative to 6 months after surgery | 
| Neuropathic pain diagnostic | evaluated by neuropathic pain diagnostic questionnaire (DN4) | preoperative to 6 months after surgery | 
| Postoperative rehabilitation | evaluated by the Brief Pain Questionary (BPI) | preoperative to 6 months after surgery | 
| Health related quality of life | evaluated by the SF-12 Health Survey | preoperative to 6 months after surgery | 
| Anxiety and Depression | evaluated by the Hospital Anxiety and Depression scale (HAD) | preoperative to 6 months after surgery | 
| Pain level perception | evaluated by the The pain Catastrophizing Scale | preoperative to 6 months after surgery | 
| Assessment of functional capacities in knee arthritis | evaluated by the Western Ontario and McMaster Universities Arthritis Index (WOMAC) | preoperative to 6 months after surgery | 
| Oxidative stress marker | 8-iso-prostaglandin F2α level by biochemical labeling | preoperative to 6 months after surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Chronic Postoperative Pain, Brain Derived Neurotrophic Factor