Why Does my Shoulder Hurt? Understanding the Presence of Pain in Individuals With Full-thickness Rotator Cuff Tears

Study Overview
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Brief Summary
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Full-thickness rotator cuff tears (FTRCT), defined as through-and-through tears of one of the shoulder tendons, affect up to 32% of the population (mostly individuals older than 50 years) and are one of the most painful and debilitating shoulder diagnoses. One of the primary challenges for clinical decision-making is the poor association between the presence of FTRCT (detected by medical imaging) and pain, as studies have shown that 2/3 of people with FTRCT are asymptomatic. This challenges the notion that FTRCT causes pain, and highlights the fact that symptoms may be explained by other variables. A better understanding of the factors leading to the development of pain in people with FTRCT would optimize clinical care (including prevention). The objective of this study is to identify variables associated with pain in people with FTRCT by 1) comparing people with FTRCT with (Symptomatic Group; n=40) and without pain (Asymptomatic Group; n=40); 2) comparing people who initially have pain-free FTRCT (Asymptomatic Group) who develop pain over a 2-year period to those who do not develop pain; and 3) comparing people who initially have painful FTRCT (Symptomatic Group) who become pain-free over a 2-year period to those who remain symptomatic. All participants will undergo an ultrasound examination to confirm the presence of FTRCT, and information on a number of variables (sociodemographic, anatomical, genetic, psychosocial, pain sensitivity, neuromuscular, biomechanical) will be collected. All participants will then be followed for 2 years before being revaluated for pain. Variables will be analysed to determine those associated with pain. As it is crucial to improve our understanding of the mechanisms leading to pain, this project has the potential to impact the musculoskeletal health of Canadians. By considering multiple variables associated with FTRCT, its results could lead to the development of tangible solutions to optimize prevention and recovery.

Detailed Description
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Background: Symptomatic full-thickness rotator cuff tears (FTRCT) affect up to 32% of the population and represent one of the more painful and debilitating shoulder diagnoses. The prevailing model for care pathway decisions is heavily influenced by medical imaging. Yet, the association between FTRCT observed on medical imaging and the presence of pain is poor, as two thirds of FTRCT are asymptomatic. This poses a great challenge to clinical decision-making and questions the belief that FTRCT causes pain. As other factors may explain the presence of pain, a better understanding of this phenomenon needs to be sought. Objective/hypothesis: The primary objective is to identify variables associated with the presence of pain in individuals with FTRCT. The hypothesis is that given its complex aetiology, no single outcome will be highly associated with pain, rather it will be important to consider several outcomes and their interactions. Secondary objectives include: to explore if a) baseline variables or b) a change in these variables following baseline can predict the development of pain in individuals who initially have asymptomatic FTRCT, and to study if a) baseline variables or b) a change in these variables following baseline can predict the resolution of pain in individuals who initially have symptomatic FTRCT. Methods: 40 adults with a FTRCT and shoulder pain (Symptomatic Group), and 40 adults with a FTRCT without shoulder pain (Asymptomatic Group) will be included. They will demonstrate a FTRCT on US examinations performed by a radiologist. Included participants will take part in a baseline evaluation during which sociodemographic, anatomical, genetic, psychosocial, pain sensitivity, neuromuscular and biomechanical variables will be assessed. The primary objective (cross-sectional design) will be achieved by determining if differences between groups are based on a sole or on several independent variables, and their relative impact on pain (recursive partitioning, principal component analysis, MANOVA). The secondary objectives (prospective design) will be achieved by following all participants for 2 years. Every 3 months, the participants will complete a web-based questionnaire asking if they have had shoulder pain. Participants in the Asymptomatic Group who develop pain and participants in the Symptomatic Group who become pain-free will be asked to participate in a follow-up evaluation within a week. Participants who remain pain-free in the Asymptomatic Group and with pain in the Symptomatic Group during the follow-up period will also be asked to participate in a follow-up evaluation at the end of the 2 years (same follow-up evaluation for all participants, similar to baseline evaluations). Logistic regressions will be used to identify the variables associated with pain development and with pain resolution. Relevance: Before implementing new intervention strategies, a better understanding of factors associated with the presence of pain is needed. By looking at different variables that could explain pain, this project will improve our understanding of FTRCT and fill important knowledge gaps.

Official Title
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Why Does my Shoulder Hurt? Identifying Factors Associated With the Presence of Pain in Individuals With Full-thickness Rotator Cuff Tears

Conditions
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Full-thickness Rotator Cuff Tear

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria (all participants): Presence of a full-thickness rotator cuff tear (on ultrasound examination performed by a radiologist) 50 to 80 years of age Degenerative tear (no significant trauma) Inclusion Criteria for the Symptomatic group: unilateral or bilateral shoulder pain (at least 2/10 on a visual analog scale [VAS] evaluating usual shoulder pain) positive response to: 'In the past 4 weeks, have you had pain in your shoulder' and 'If yes, was this pain bad enough to limit your usual activities or change your daily routine for more than 1 day?' Inclusion Criteria for the Asymptomatic group: report no current shoulder pain (0/10 on a VAS evaluating usual shoulder pain) negative response to: 'In the past 4 weeks, have you had pain in your shoulder' do not report any past significant shoulder pain (any pain greater than or equal to 2/10 that lasted longer than 4 weeks, required the use of medications or prompted a physician visit) Exclusion Criteria: unable to understand French or English; history of upper limb fracture; previous shoulder surgery; cervicobrachialgia or shoulder pain reproduced by neck movement; shoulder capsulitis (restriction of at least 30% in 2 or more directions); rheumatoid, inflammatory or neurological diseases; corticosteroid injection in the previous 6 weeks; cognitive problems interfering with evaluations (Mini-Mental State Examination ≥ 24)

Ages Eligible for Study
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Minimum Age: 50 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Symptomatic<br>No intervention. | |
| Asymptomatic<br>No intervention. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in usual shoulder pain from baseline: Visual analog scale (VAS) | Participants will be asked to rate the intensity of their pain on a VAS from 0 to 10, where 0 represents no pain and 10 represents worst pain imaginable, in the last week, month and 3 months. Highest possible score (worst outcome): 30. Lowest possible score (best outcome): 0. Method to compute total score: sum of each score. | From baseline to the follow-up evaluation (end of the 2-year period) (Objective 2 and 3) | 
| usual shoulder pain from baseline: Visual analog scale (VAS) | Participants will be asked to rate the intensity of their pain on a VAS from 0 to 10, | Baseline score (Objective 1) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline with regard to: Sociodemographic and occupational factors | General sociodemographic questionnaire including sex; gender; date of birth; age; height; weight; hand dominance; racial, ethnic or cultural origin; civil status; education level; occupation; employment status; overhead sports activities (currently or previously); household income; smoking habits | From baseline to the follow-up evaluation (end of the 2-year period)(Objective 2 and 3) | 
| Sociodemographic and occupational factors | General sociodemographic questionnaire including sex; gender; date of birth; age; height; weight; hand dominance; racial, ethnic or cultural origin; civil status; education level; occupation; employment status; overhead sports activities (currently or previously); household income; smoking habits | Baseline characteristics (Objective 1) | 
| Change in disability and functional limitations of the upper extremity from baseline: QuickDASH | Questionnaire comprising 11 questions evaluating disability and functional limitations of the upper extremity on a scale from 1 to 5, where 1 denotes full capacity and 5 denotes incapacity | From baseline to the follow-up evaluation (end of the 2-year period)(Objective 2 and 3) | 
| Disability and functional limitations of the upper extremity QuickDASH | Questionnaire comprising 11 questions evaluating disability and functional limitations of the upper extremity on a scale from 1 to 5, where 1 denotes full capacity and 5 denotes incapacity | Baseline score (Objective 1) | 
| Change in comorbidities from baseline: Self-Administered Comorbidity Questionnaire | Questionnaire determining the presence or absence of 13 health problems, whether or not the person is treated for each problem, and whether or not the problem interferes with / limits their activities | From baseline to the follow-up evaluation (end of the 2-year period)(Objective 2 and 3) | 
| Comorbidities: Self-Administered Comorbidity Questionnaire | Questionnaire determining the presence or absence of 13 health problems, whether or not the person is treated for each problem, and whether or not the problem interferes with / limits their activities | Baseline score (Objective 1) | 
| Change in sleep disturbance from baseline: PROMIS Sleep Disturbance Questionnaire | Qualitative questionnaire on a 5-point Likert scale, where higher scores indicate greater sleep quality | From baseline to the follow-up evaluation (end of the 2-year period)(Objective 2 and 3) | 
| Sleep disturbance: PROMIS Sleep Disturbance Questionnaire | Qualitative questionnaire on a 5-point Likert scale, where higher scores indicate greater sleep quality | Baseline score (Objective 1) | 
| Change in prevalence and frequency of symptoms from baseline: Nordic Musculoskeletal Questionnaire | Questionnaire evaluating the prevalence of pain (dichotomous scale, yes or no) in all regions of the body (in the last week, last 3 months and last 12 months), and the frequency of pain/symptoms in each region of the body (scale from 0 to 3, where higher scores indicate higher frequency of symptoms) | From baseline to the follow-up evaluation (end of the 2-year period)(Objective 2 and 3) | 
| Prevalence and frequency of symptoms from baseline: Nordic Musculoskeletal Questionnaire | Questionnaire evaluating the prevalence of pain (dichotomous scale, yes or no) in all regions of the body (in the last week, last 3 months and last 12 months), and the frequency of pain/symptoms in each region of the body (scale from 0 to 3, where higher scores indicate higher frequency of symptoms) | Baseline score (Objective 1) | 
| Change in anxiety from baseline: State-Trait Anxiety Inventory | 6 items each scored on a 4-point scale, higher scores denote greater anxiety | From baseline to the follow-up evaluation (end of the 2-year period)(Objective 2 and 3) | 
| Anxiety from baseline: State-Trait Anxiety Inventory | 6 items each scored on a 4-point scale, higher scores denote greater anxiety | Baseline score (Objective 1) | 
| Change in depressive symptoms from baseline: Patient Health Questionnaire | 9-item questionnaire evaluating depressive symptoms, on a 4-point scale where higher scores denote higher frequency of depressive symptoms | From baseline to the follow-up evaluation (end of the 2-year period)(Objective 2 and 3) | 
| Depressive symptoms from baseline: Patient Health Questionnaire | 9-item questionnaire evaluating depressive symptoms, on a 4-point scale where higher scores denote higher frequency of depressive symptoms | Baseline score (Objective 1) | 
| Change in perceived stress from baseline: Perceived Stress Scale 4 | 4-item questionnaire, scored on a 5-point scale from 0 (never) to 4 (very often). Higher scores are correlated to more stress. | From baseline to the follow-up evaluation (end of the 2-year period)(Objective 2 and 3) | 
| Perceived stress from baseline: Perceived Stress Scale 4 | 4-item questionnaire, scored on a 5-point scale from 0 (never) to 4 (very often). Higher scores are correlated to more stress. | Baseline score (Objective 1) | 
| Change in upper extremity work demands from baseline: Revised Upper Extremity Work Demands Scale (currently and previously) | 6-item scale scored from 1 (rarely / never) to 4 (almost always), higher scores indicate greater physical work demands on the upper extremity. | From baseline to the follow-up evaluation (end of the 2-year period)(Objective 2 and 3) | 
| Upper extremity work demands from baseline: Revised Upper Extremity Work Demands Scale (currently and previously) | 6-item scale scored from 1 (rarely / never) to 4 (almost always), higher scores indicate greater physical work demands on the upper extremity. | Baseline score (Objective 1) | 
| Change in pain catastrophising from baseline: Pain Catastrophising Scale | 13-item questionnaire, 5-point scale, greater scores indicate more pain catastrophizing. | From baseline to the follow-up evaluation (end of the 2-year period)(Objective 2 and 3) | 
| Pain catastrophising from baseline: Pain Catastrophising Scale | 13-item questionnaire, 5-point scale, greater scores indicate more pain catastrophizing. | Baseline score (Objective 1) | 
| Change in Structural tissue damage of the shoulder from baseline (ultrasound evaluation performed by a radiologist) | Full thickness rotator cuff tears will be classified by size defined as small (<10 mm), medium (10 to 30 mm) or large (>30 mm) | From baseline to the follow-up evaluation (end of the 2-year period)(Objective 2 and 3) | 
| Structural tissue damage of the shoulder from baseline (ultrasound evaluation performed by a radiologist) | Full thickness rotator cuff tears will be classified by size defined as small (<10 mm), medium (10 to 30 mm) or large (>30 mm) | Baseline observations (Objective 1) | 
| Change in Acromiohumeral distance from baseline | Ultrasound (US scanner) will be used to measure the acromiohumeral distance of the affected shoulder at 0 degrees and 60 degrees of shoulder abduction | From baseline to the follow-up evaluation (end of the 2-year period)(Objective 2 and 3) | 
| Acromiohumeral distance from baseline | Ultrasound (US scanner) will be used to measure the acromiohumeral distance of the affected shoulder at 0 degrees and 60 degrees of shoulder abduction | Baseline distance (Objective 1) | 
| Change in Radiographical evaluation of the shoulder from baseline | Presence or absence of calcific tendonitis and/or osteophytes at the glenohumeral and acromioclavicular joints | From baseline to the follow-up evaluation (end of the 2-year period)(Objective 2 and 3) | 
| Radiographical evaluation of the shoulder from baseline | Presence or absence of calcific tendonitis and/or osteophytes at the glenohumeral and acromioclavicular joints | Baseline observation (Objective 1) | 
| Change in pain sensitivity from baseline: Pressure Pain Threshold (PPT) | PPT will be assessed bilaterally at the middle deltoid and tibialis anterior muscles using a mechanical pressure algometer at an applied rate of 1 kg/s. The amount of pressure at which pain is perceived (in Newtons) will be recorded (mean of 3 trials). Higher scores denote less pain sensitivity. | From baseline to the follow-up evaluation (end of the 2-year period)(Objective 2 and 3) | 
| Pain sensitivity from baseline: Pressure Pain Threshold (PPT) | PPT will be assessed bilaterally at the middle deltoid and tibialis anterior muscles using a mechanical pressure algometer at an applied rate of 1 kg/s. The amount of pressure at which pain is perceived (in Newtons) will be recorded (mean of 3 trials). Higher scores denote less pain sensitivity. | Baseline score (Objective 1) | 
| Change in Range of Motion (ROM) of the affected shoulder from baseline | Shoulder ROM in flexion, lateral rotation at 0° abduction, and lateral and medial rotation at 90° abduction will be measured using a goniometer (flexion) and an inclinometer (other measures). Values will be compared to normative data according to age. | From baseline to the follow-up evaluation (end of the 2-year period)(Objective 2 and 3) | 
| Range of Motion (ROM) of the affected shoulder from baseline | Shoulder ROM in flexion, lateral rotation at 0° abduction, and lateral and medial rotation at 90° abduction will be measured using a goniometer (flexion) and an inclinometer (other measures). Values will be compared to normative data according to age. | Baseline ROM (Objective 1) | 
| Change in Bilateral grip strength with handheld dynamometer from baseline | Measured in pounds. | From baseline to the follow-up evaluation (end of the 2-year period)(Objective 2 and 3) | 
| Bilateral grip strength with handheld dynamometer from baseline | Measured in pounds. | Baseline score (Objective 1) | 
| Change in Isometric shoulder strength from baseline, with manual dynamometer | Isometric shoulder strength in abduction and in lateral rotation at 0° abduction will be measured in Newtons with a manual dynamometer (MedUp), and normalized by lever arm, measured in meters using a measuring tape. | BFrom baseline to the follow-up evaluation (end of the 2-year period)(Objective 2 and 3) | 
| Isometric shoulder strength from baseline, with manual dynamometer | Isometric shoulder strength in abduction and in lateral rotation at 0° abduction will be measured in Newtons with a manual dynamometer (MedUp), and normalized by lever arm, measured in meters using a measuring tape. | Baseline score (Objective 1) | 
| Change in scapular dyskinesis from baseline: Scapula Dyskinesis Test | Bilateral scapular dyskinesis measured on a 3-point scale: normal (0 points), subtle (1 point), obvious (2 points). Higher scores indicate greater dyskinesis. | From baseline to the follow-up evaluation (end of the 2-year period)(Objective 2 and 3) | 
| Scapular dyskinesis from baseline: Scapula Dyskinesis Test | Bilateral scapular dyskinesis measured on a 3-point scale: normal (0 points), subtle (1 point), obvious (2 points). Higher scores indicate greater dyskinesis. | Baseline score (Objective 1) | 
| Change from baseline in Shoulder proprioception (arm position matching), coordination and functional dominance with the KINARM exoskeleton (BKIN Technologies) | Three KINARM standard tasks will be used to evaluate bilateral upper extremity neuromuscular control. Units of measurement: error in cm and task score (arm position matching task), and task score for the coordination and functional dominance tasks. Task scores are calculated by KINARM software according to variables such as precision and speed. | From baseline to the follow-up evaluation (end of the 2-year period)(Objective 2 and 3) | 
| Shoulder proprioception (arm position matching), coordination and functional dominance with the KINARM exoskeleton (BKIN Technologies) | Three KINARM standard tasks will be used to evaluate bilateral upper extremity neuromuscular control. Units of measurement: error in cm and task score (arm position matching task), and task score for the coordination and functional dominance tasks. Task scores are calculated by KINARM software according to variables such as precision and speed. | Baseline score (Objective 1) |