Neurophysiological Mechanisms Involved in Knee Osteoarthritis

Study Overview
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Brief Summary
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Introduction: Total knee arthroplasty (TKA) is an effective intervention to relieve people with osteoarthritis (OA). Nevertheless, 15 to 30% of patients continue to experience severe pain following surgery. Recent data suggest that central nervous system (CNS) changes may play a role in OA pain and possibly explain why some patients have poorer clinical outcomes following TKA. Objectives: Our main objectives are to explore the relationship between OA pain and (1) the integrity of corticospinal system, (2) the efficacy of descending pain inhibition circuits. Methods: Fifty-two patients waiting for TKA will be recruited. The integrity of the corticospinal projections will be measured using transcranial magnetic stimulation (recruitment curve of the affected quadriceps femoris muscle) and the descending pain inhibition circuits (bulbospinal projections) will be assessed by a counter-irritation paradigm (i.e., conditioned pain modulation with immersion of the arm in painfully cold water). Diffuse tension imaging (DTI) will also be used to quantify the strength of these corticospinal and bulbospinal projections. Clinical outcomes will be evaluated before and after arthroplasty with a series of validated questionnaires such as the WOMAC Scale, the McGill Pain Questionnaire and the Brief Pain Inventory. These different neurophysiological and clinical measures will be taken before surgery, 6 months after surgery and 1 year post-surgery. Anticipated results: The investigators expect a moderate association between pain and the strength of the corticospinal and bulbospinal projections. Moreover, it is expected that there will be a moderate association between the strength of the corticospinal/bulbospinal projections and the clinical evolution of patients.

Detailed Description
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See outcome measures

Official Title
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Pain in Individuals With Knee Osteoarthritis : Beyond the Joint and the Musculoskeletal System

Conditions
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Knee Osteoarthritis, Chronic Pain

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Being an adults aged 50-79 years old with a diagnosis of knee OA and waiting for a primary arthroplasty Refrain from consuming cigarettes and caffeine 2 hours and 6 hours before testing, respectively Refrain from taking short-acting analgesics (e.g., acetaminophen) 6 hours before testing Exclusion Criteria: Having difficulty understanding french language Having a diagnosis of neurological disorder or diagnosis of chronic pain (other knee OA) Having metal implants in the skull Having pacemaker or neurostimulator Being pregnant Being epileptic

Ages Eligible for Study
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Minimum Age: 50 Years
Maximum Age: 79 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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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline - Integrity of the corticospinal system | This outcome will be measured by transcranial magnetic stimulation (TMS) | Before surgery, 6 months and 1 year post-surgery | 
| Change from baseline - Descending pain inhibition circuits | This outcome will be measured by a counter-irritation paradigm (conditioned pain modulation using a thermode and a bath of circulating cold water) | Before surgery, 6 months and 1 year post-surgery | 
| Change from baseline - Pain intensity | This outcome will be measured by a visual analogue scale (VAS). The VAS is a straight horizontal line of fixed length, usually 10 cm. The ends are defined as the extreme limits of the parameter to be measured; 0 = no pain, 10 = the worst imaginable pain. Using a ruler, the score is determined by measuring the distance (cm) on the 10 cm line between the no pain anchor and the patient's mark, providing a range of scores from 0-10. A higher score indicates greater pain intensity. | Before surgery, 6 months and 1 year post-surgery | 
| Change from baseline - Pain, stiffness and physical function | This outcome will be measured by Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) | Before surgery, 6 months and 1 year post-surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain catastrophizing | This outcome will be measured with the Pain Catastrophizing Scale (PCS) . The PCS inquire participants to reflect on past painful experiences, and to indicate the degree to which they experienced each of 13 thoughts or feelings when experiencing pain. Each item of the PCS is scored on a 5-point scale where 0 = not at all and 4 = all the time. PCS yields three subscale scores assessing rumination, magnification and helplessness. The PCS total score is computed by summing responses to all 13 items. The PCS yields a total score ranging from 0 to 52. Higher values on this scale represent a greater tendency of the subject to perceive pain negatively and to foresee the consequences of pain in a more catastrophic way. | Before surgery, 6 months and 1 year post-surgery | 
| Kinesiophobia | This outcome will be measured with the Tampa Scale of Kinesiophobia (TSK) . The TSK is a 17-item self-report checklist using a 4-point Likert scale that was developed as a measure of fear of movement or (re)injury. The total score ranges between 17 and 68. A high value on the TSK indicates a high degree of kinesiophobia, and a cutoff score was developed by Vlaeyen (1995), where a score of 37 or over is considered as a high score, while scores below that are considered as low scores. | Before surgery, 6 months and 1 year post-surgery | 
| Anxiety | This outcome will be measured with the Spielberger's State-Trait Anxiety Inventory | Before surgery, 6 months and 1 year post-surgery | 
| Qualitative aspect of pain | This outcome will be measured by the McGill Pain Questionnaire | Before surgery, 6 months and 1 year post-surgery | 
| Impact of pain on physical function and quality of life | This outcome will be measured by the Brief Pain Inventory (BPI) | Before surgery, 6 months and 1 year post-surgery | 
| Functional autonomy, social autonomy | This outcome will be measured by the SMAF questionnaire | Before surgery, 6 months and 1 year post-surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Arthritis, Chronic pain, Transcranial magnetic stimulation (TMS), Magnetic resonance imaging (MRI), Conditioned pain modulation (CPM), Clinical measures, Knee osteoarthritis