Clinical Phenotypes in Persons With Hip Osteoarthritis and Prognostic Factors for Outcome After Total Hip Arthroplasty

Hip Osteoarthritis Clinical Trial

— HIPPROCLIPS  

Official title:

Clinical Phenotypes in Persons With Hip Osteoarthritis and Prognostic Factors for Outcome After Total Hip Arthroplasty

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT05265858
• Other study ID #: B3712021000002
• Secondary ID: CTU2020128
• Status: Recruiting
• Start date: May 4, 2021
• Est. completion date: February 2024

Study information

• Verified date: February 2022
• Source: Hasselt University
• Contact: Abner Sergooris
• Phone: 003211299187
• Email: abner.sergooris[@]uhasselt.be
• Is FDA regulated: No
• Study type: Observational

Clinical Trial Summary

This prospective longitudinal cohort study aims (1) to identify clinical phenotypes in persons with hip osteoarthritis and after total hip arthroplasty, and (2) to identify prognostic factors for outcomes after total hip arthroplasty.

Description:

Osteoarthritis (OA) is one of the leading causes of pain and disability worldwide, with more than 300 million people currently affected by the disease. The hip joint is clinically one of the most affected locations of OA. Each year, more than 40 million prevalent cases and more than 2 million incident cases of hip OA are reported worldwide. The global prevalence and incidence of hip OA are expected to increase considerably in the upcoming decades, as a result of the aging population and an increasing prevalence of risk factors such as obesity and sedentary lifestyle. Since the population with hip OA is highly heterogeneous, individualized care pathways are needed instead of the current one-size-fits-all approach in clinical management. The identification of distinct subgroups within the population with hip OA might offer a foundation for individualized care pathways with the potential improvement of clinical outcomes. Therefore, the first aim of this longitudinal prospective cohort study is to identify clinical phenotypes in persons with hip osteoarthritis based on a set of contributing biopsychosocial variables, and to compare these phenotypes in terms of pain and disability before and after total hip arthroplasty (THA).

Correspondingly with the increasing prevalence and incidence of hip OA, the mean utilization rate of hip implants per 100.000 inhabitants in Organisation for Economic Co-operation and Development (OECD) countries is expected to increase from 145 in 2010 to 275 in 2050. Annually, more than 30.000 THA's are performed in Belgium. This number is growing considerably, especially in younger, working-age patients. Total hip arthroplasty (THA) is a cost-effective procedure in patients with end-stage hip OA. However, previous studies have reported that 8% of patients are dissatisfied with the outcome, and up to 23% of patients report long-term pain after THA. Furthermore, over 30% of patients report activity limitations and about 25% of patients report participation restrictions after THA. An important step towards understanding and improving outcomes after THA is prognostic factor research. Therefore, the second aim of this clinical study is to identify prognostic factors for outcomes of pain and disability after THA in persons with hip OA.

In this prospective longitudinal cohort study, 200 persons undergoing total hip arthroplasty for hip OA will be followed one-year post-surgery. Participants are recruited at the orthopaedic department of 'Ziekenhuis Oost-Limburg' in Genk and at 'de heuppraktijk' in Herselt. Participants will be assessed on a set of biopsychosocial variables, including pain-related fear-avoidance behavior, perceived injustice, psychopathology, traumatic experiences, social support, and self-efficacy. Furthermore, the somatosensory function will be assessed with thermal quantitative sensory testing (QST) and muscle strength will be assessed with a handheld dynamometer (MicroFet 2). Outcome measures include the Hip Disability and Osteoarthritis Outcome Score (HOOS), the OARSI recommended minimum core set of performance-based outcome measures (PBMs), the Patient-Specific Functional Scale (PSFS), Pain intensity (NPRS), Global Perceived Effect (GPE), and satisfaction (NRS). All these measurements will be performed before surgery, as well as 6 weeks, 3 months, and 12 months after surgery. Pain-related fear-avoidance behavior, perceived injustice, anxiety, depression, and pain will be assessed in the early postoperative phase.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 200
• Est. completion date: February 2024
• Est. primary completion date: February 2024
• Accepts healthy volunteers: No
• Gender: All
• Age group: N/A and older

Eligibility

Inclusion Criteria:

• Persons with a confirmed clinical or radiographic primary diagnosis of hip osteoarthritis who will undergo total hip arthroplasty (THA)

Exclusion Criteria:

• Rheumatoid arthritis or other rheumatic diseases

• Another pathological condition explaining the symptoms (e.g. avascular necrosis)

• Neurological condition (e.g. Parkinson's disease, stroke...) significantly influencing the symptoms of hip osteoarthritis.

• Revision THA

• History of pathological fractures (e.g. osteoporosis, tumor...)

• Contralateral THA during follow-up period

• Total knee arthroplasty (TKA) during follow-up period

• Another surgery planned during follow-up period

Related Conditions & MeSH terms

• Hip Osteoarthritis
• Osteoarthritis
• Osteoarthritis, Hip
• Total Hip Arthroplasty

Intervention

Procedure:
• Total Hip Arthroplasty
Direct Anterior Approach (DAA) Total Hip Arthroplasty (THA)

Locations

Country	Name	City	State
Belgium	Ziekenhuis Oost-Limburg	Genk	Limburg
Belgium	Heuppraktijk	Herselt	Antwerpen

Sponsors (3)

Lead Sponsor	Collaborator
Hasselt University	Bijzonder onderzoeksfonds (BOF), Ziekenhuis Oost-Limburg

Country where clinical trial is conducted

Belgium, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Other	Thermal Detection and Pain Threshold Temperatures	Thermal Quantitative sensory testing (QST) will be used to investigate nociceptive stimulus processing. QST is a non-invasive examination of the somatosensory system commonly used in pain diagnosis. The Medoc Advanced Thermosensory Stimulator (TSA) - 2 system will be used to perform a standardized test protocol.; Detection and pain threshold temperatures (in °C) will be assessed locally (at the most painful site of the hip) and remotely (at the contralateral wrist) using the TSA limits protocol: Cold Detection Threshold (CDT); Warmth Detection Threshold (WDT); Cold Pain Threshold (CPT); Heat Pain Threshold (HPT)	1 week before THA
Other	Thermal Detection and Pain Threshold Temperatures	Thermal Quantitative sensory testing (QST) will be used to investigate nociceptive stimulus processing. QST is a non-invasive examination of the somatosensory system commonly used in pain diagnosis. The Medoc Advanced Thermosensory Stimulator (TSA) - 2 system will be used to perform a standardized test protocol.; Detection and pain threshold temperatures (in °C) will be assessed locally (at the most painful site of the hip) and remotely (at the contralateral wrist) using the TSA limits protocol: Cold Detection Threshold (CDT); Warmth Detection Threshold (WDT); Cold Pain Threshold (CPT); Heat Pain Threshold (HPT)	6 weeks after THA
Other	Thermal Detection and Pain Threshold Temperatures	Thermal Quantitative sensory testing (QST) will be used to investigate nociceptive stimulus processing. QST is a non-invasive examination of the somatosensory system commonly used in pain diagnosis. The Medoc Advanced Thermosensory Stimulator (TSA) - 2 system will be used to perform a standardized test protocol.; Detection and pain threshold temperatures (in °C) will be assessed locally (at the most painful site of the hip) and remotely (at the contralateral wrist) using the TSA limits protocol: Cold Detection Threshold (CDT); Warmth Detection Threshold (WDT); Cold Pain Threshold (CPT); Heat Pain Threshold (HPT)	3 months after THA
Other	Thermal Detection and Pain Threshold Temperatures	Thermal Quantitative sensory testing (QST) will be used to investigate nociceptive stimulus processing. QST is a non-invasive examination of the somatosensory system commonly used in pain diagnosis. The Medoc Advanced Thermosensory Stimulator (TSA) - 2 system will be used to perform a standardized test protocol.; Detection and pain threshold temperatures (in °C) will be assessed locally (at the most painful site of the hip) and remotely (at the contralateral wrist) using the TSA limits protocol: Cold Detection Threshold (CDT); Warmth Detection Threshold (WDT); Cold Pain Threshold (CPT); Heat Pain Threshold (HPT)	12 months after THA
Other	Temporal Summation of Pain (TSP)	Thermal Quantitative sensory testing (QST) will be used to investigate nociceptive stimulus processing. QST is a non-invasive examination of the somatosensory system commonly used in pain diagnosis. The Medoc TSA-2 system will be used to perform a standardized test protocol.; Temporal summation of pain (TSP) will be assessed at the contralateral wrist using a 2-minute tonic heat stimulus and patient-controlled temperature. Participants are presented with a tonic heat stimulus and are instructed to maintain their initial sensation for two minutes via the remote controller. To quantify temporal adaptation and temporal summation of pain, the slope and magnitude of temperature changes will be extracted and the areas under the curve will be calculated.	1 week before THA
Other	Temporal Summation of Pain (TSP)	Thermal Quantitative sensory testing (QST) will be used to investigate nociceptive stimulus processing. QST is a non-invasive examination of the somatosensory system commonly used in pain diagnosis. The Medoc TSA-2 system will be used to perform a standardized test protocol.; Temporal summation of pain (TSP) will be assessed at the contralateral wrist using a 2-minute tonic heat stimulus and patient-controlled temperature. Participants are presented with a tonic heat stimulus and are instructed to maintain their initial sensation for two minutes via the remote controller. To quantify temporal adaptation and temporal summation of pain, the slope and magnitude of temperature changes will be extracted and the areas under the curve will be calculated.	6 weeks after THA
Other	Temporal Summation of Pain (TSP)	Thermal Quantitative sensory testing (QST) will be used to investigate nociceptive stimulus processing. QST is a non-invasive examination of the somatosensory system commonly used in pain diagnosis. The Medoc TSA-2 system will be used to perform a standardized test protocol.; Temporal summation of pain (TSP) will be assessed at the contralateral wrist using a 2-minute tonic heat stimulus and patient-controlled temperature. Participants are presented with a tonic heat stimulus and are instructed to maintain their initial sensation for two minutes via the remote controller. To quantify temporal adaptation and temporal summation of pain, the slope and magnitude of temperature changes will be extracted and the areas under the curve will be calculated.	3 months after THA
Other	Temporal Summation of Pain (TSP)	Thermal Quantitative sensory testing (QST) will be used to investigate nociceptive stimulus processing. QST is a non-invasive examination of the somatosensory system commonly used in pain diagnosis. The Medoc TSA-2 system will be used to perform a standardized test protocol.; Temporal summation of pain (TSP) will be assessed at the contralateral wrist using a 2-minute tonic heat stimulus and patient-controlled temperature. Participants are presented with a tonic heat stimulus and are instructed to maintain their initial sensation for two minutes via the remote controller. To quantify temporal adaptation and temporal summation of pain, the slope and magnitude of temperature changes will be extracted and the areas under the curve will be calculated.	12 months after THA
Other	Conditioned Pain Modulation (CPM)	Thermal Quantitative sensory testing (QST) will be used to investigate nociceptive stimulus processing. The Medoc TSA-2 system will be used to perform a standardized test protocol.; Conditioned pain modulation will be evaluated using a Dual-Thermode program with two different stimuli: Test stimulus: this heat stimulus will be administered twice at the contralateral wrist. Once on its own before administering the conditioning stimulus, and once during the conditioning heat stimulus at the ipsilateral wrist.; Conditioning stimulus: this heat stimulus will be administered at the ipsilateral wrist after first applying the test stimulus.; The difference in pain intensity at the contralateral wrist during the stand-alone test stimulus and the test stimulus during the conditioning stimulus will be calculated. Pain intensity is assessed using a Numerical Pain Rating Scale (NPRS) ranging from 0 to 100, where 0 stands for "no pain", and 100 for "worst imaginable pain".	1 week before THA
Other	Conditioned Pain Modulation (CPM)	Thermal Quantitative sensory testing (QST) will be used to investigate nociceptive stimulus processing. The Medoc TSA-2 system will be used to perform a standardized test protocol.; Conditioned pain modulation will be evaluated using a Dual-Thermode program with two different stimuli: Test stimulus: this heat stimulus will be administered twice at the contralateral wrist. Once on its own before administering the conditioning stimulus, and once during the conditioning heat stimulus at the ipsilateral wrist.; Conditioning stimulus: this heat stimulus will be administered at the ipsilateral wrist after first applying the test stimulus.; The difference in pain intensity at the contralateral wrist during the stand-alone test stimulus and the test stimulus during the conditioning stimulus will be calculated. Pain intensity is assessed using a Numerical Pain Rating Scale (NPRS) ranging from 0 to 100, where 0 stands for "no pain", and 100 for "worst imaginable pain".	6 weeks after THA
Other	Conditioned Pain Modulation (CPM)	Thermal Quantitative sensory testing (QST) will be used to investigate nociceptive stimulus processing. The Medoc TSA-2 system will be used to perform a standardized test protocol.; Conditioned pain modulation will be evaluated using a Dual-Thermode program with two different stimuli: Test stimulus: this heat stimulus will be administered twice at the contralateral wrist. Once on its own before administering the conditioning stimulus, and once during the conditioning heat stimulus at the ipsilateral wrist.; Conditioning stimulus: this heat stimulus will be administered at the ipsilateral wrist after first applying the test stimulus.; The difference in pain intensity at the contralateral wrist during the stand-alone test stimulus and the test stimulus during the conditioning stimulus will be calculated. Pain intensity is assessed using a Numerical Pain Rating Scale (NPRS) ranging from 0 to 100, where 0 stands for "no pain", and 100 for "worst imaginable pain".	3 months after THA
Other	Conditioned Pain Modulation (CPM)	Thermal Quantitative sensory testing (QST) will be used to investigate nociceptive stimulus processing. The Medoc TSA-2 system will be used to perform a standardized test protocol.; Conditioned pain modulation will be evaluated using a Dual-Thermode program with two different stimuli: Test stimulus: this heat stimulus will be administered twice at the contralateral wrist. Once on its own before administering the conditioning stimulus, and once during the conditioning heat stimulus at the ipsilateral wrist.; Conditioning stimulus: this heat stimulus will be administered at the ipsilateral wrist after first applying the test stimulus.; The difference in pain intensity at the contralateral wrist during the stand-alone test stimulus and the test stimulus during the conditioning stimulus will be calculated. Pain intensity is assessed using a Numerical Pain Rating Scale (NPRS) ranging from 0 to 100, where 0 stands for "no pain", and 100 for "worst imaginable pain".	12 months after THA
Other	Mini International Neuropsychiatric Interview - Simplified (M.I.N.I.-S for DSM-V)	The MINI-S is a brief structured diagnostic interview for the major psychiatric disorders in the DSM-5. The MINI-S assesses the 17 most common disorders in mental health, including Bipolar Disorder Type 1 and Type 2, Major Depressive Disorder, Social Anxiety Disorder, Panic Disorder, Agoraphobia, Generalized Anxiety Disorder, Obsessive Compulsive Disorder, Post-Traumatic Stress Disorder, Acute Stress Disorder, Attention-Deficit/Hyperactivity Disorder, Anorexia Nervosa, Bulimia Nervosa, Alcohol Use Disorder, Substance other than alcohol Use Disorder, Psychotic Disorders.	1 week before THA
Other	Mini International Neuropsychiatric Interview - Simplified (M.I.N.I.-S for DSM-V)	The MINI-S is a brief structured diagnostic interview for the major psychiatric disorders in the DSM-5. The MINI-S assesses the 17 most common disorders in mental health, including Bipolar Disorder Type 1 and Type 2, Major Depressive Disorder, Social Anxiety Disorder, Panic Disorder, Agoraphobia, Generalized Anxiety Disorder, Obsessive Compulsive Disorder, Post-Traumatic Stress Disorder, Acute Stress Disorder, Attention-Deficit/Hyperactivity Disorder, Anorexia Nervosa, Bulimia Nervosa, Alcohol Use Disorder, Substance other than alcohol Use Disorder, Psychotic Disorders.	12 months after THA
Other	Traumatic Experiences Checklist (TEC)	The Traumatic Experiences Checklist (TEC) is a self-reported questionnaire that investigates traumatic experiences in the past. The TEC consists of 31 items, which represent traumatic experiences. Participants should indicate whether they experienced the events and at what age it occurred. The extent to which the event was stressful for the person is also examined. This is scored on a 5-point scale ranging from 'to some extent' to 'to a very severe degree'.	1 week before THA
Other	Traumatic Experiences Checklist (TEC)	The Traumatic Experiences Checklist (TEC) is a self-reported questionnaire that investigates traumatic experiences in the past. The TEC consists of 31 items, which represent traumatic experiences. Participants should indicate whether they experienced the events and at what age it occurred. The extent to which the event was stressful for the person is also examined. This is scored on a 5-point scale ranging from 'to some extent' to 'to a very severe degree'.	12 months after THA
Other	Childhood Trauma Questionnaire (CTQ)	The CTQ is used to determine whether a person has experienced childhood trauma. The CTQ is a 25-item retrospective self-reported questionnaire that evaluates childhood events. Each question is answered on a 5-point Likert scale (1 never true, 2 often true, 3 sometimes, 4 often true, 5 true). The questionnaire assesses five dimensions of child abuse: (1) Physical abuse, (2) Emotional abuse, (3) Sexual abuse, (4) Physical neglect and (5) Emotional neglect.	1 week before THA
Other	Childhood Trauma Questionnaire (CTQ)	The CTQ is used to determine whether a person has experienced childhood trauma. The CTQ is a 25-item retrospective self-reported questionnaire that evaluates childhood events. Each question is answered on a 5-point Likert scale (1 never true, 2 often true, 3 sometimes, 4 often true, 5 true). The questionnaire assesses five dimensions of child abuse: (1) Physical abuse, (2) Emotional abuse, (3) Sexual abuse, (4) Physical neglect and (5) Emotional neglect.	12 months after THA
Other	Hospital Anxiety and Depression Scale (HADS)	The HADS is a 14-item questionnaire evaluating anxiety and depression complaints without involving physical complaints. The HADS consists of two subscales, one subscale covers symptoms of anxiety (HADS-A), the other symptoms of depression (HADS-D). Each item is scored from zero ("not applicable") to three ("certainly applicable"). The maximum score on each subscale is 21, with higher values indicating more anxiety/depression symptoms.	1 week before THA
Other	Hospital Anxiety and Depression Scale (HADS)	The HADS is a 14-item questionnaire evaluating anxiety and depression complaints without involving physical complaints. The HADS consists of two subscales, one subscale covers symptoms of anxiety (HADS-A), the other symptoms of depression (HADS-D). Each item is scored from zero ("not applicable") to three ("certainly applicable"). The maximum score on each subscale is 21, with higher values indicating more anxiety/depression symptoms.	1 week after THA
Other	Hospital Anxiety and Depression Scale (HADS)	The HADS is a 14-item questionnaire evaluating anxiety and depression complaints without involving physical complaints. The HADS consists of two subscales, one subscale covers symptoms of anxiety (HADS-A), the other symptoms of depression (HADS-D). Each item is scored from zero ("not applicable") to three ("certainly applicable"). The maximum score on each subscale is 21, with higher values indicating more anxiety/depression symptoms.	6 weeks after THA
Other	Hospital Anxiety and Depression Scale (HADS)	The HADS is a 14-item questionnaire evaluating anxiety and depression complaints without involving physical complaints. The HADS consists of two subscales, one subscale covers symptoms of anxiety (HADS-A), the other symptoms of depression (HADS-D). Each item is scored from zero ("not applicable") to three ("certainly applicable"). The maximum score on each subscale is 21, with higher values indicating more anxiety/depression symptoms.	3 months after THA
Other	Hospital Anxiety and Depression Scale (HADS)	The HADS is a 14-item questionnaire evaluating anxiety and depression complaints without involving physical complaints. The HADS consists of two subscales, one subscale covers symptoms of anxiety (HADS-A), the other symptoms of depression (HADS-D). Each item is scored from zero ("not applicable") to three ("certainly applicable"). The maximum score on each subscale is 21, with higher values indicating more anxiety/depression symptoms.	12 months after THA
Other	Fear-Avoidance Component Scale (FACS)	Pain-related fear avoidance was assessed by the Dutch version of the FACS, which is a 20-item questionnaire, with each item scored on a 6-point Likert scale, resulting in scores ranging from zero ("completely disagree") to five ("completely agree"). There is a maximum total score of 100, with higher scores indicating more fear-avoidance. Five fear-avoidance-related severity levels have been proposed: subclinical (0 to 20), mild (21 to 40), moderate (41 to 60), severe (61 to 80), and extreme (81 to 100).	1 week before THA
Other	Fear-Avoidance Component Scale (FACS)	Pain-related fear avoidance was assessed by the Dutch version of the FACS, which is a 20-item questionnaire, with each item scored on a 6-point Likert scale, resulting in scores ranging from zero ("completely disagree") to five ("completely agree"). There is a maximum total score of 100, with higher scores indicating more fear-avoidance. Five fear-avoidance-related severity levels have been proposed: subclinical (0 to 20), mild (21 to 40), moderate (41 to 60), severe (61 to 80), and extreme (81 to 100).	1 week after THA
Other	Fear-Avoidance Component Scale (FACS)	Pain-related fear avoidance was assessed by the Dutch version of the FACS, which is a 20-item questionnaire, with each item scored on a 6-point Likert scale, resulting in scores ranging from zero ("completely disagree") to five ("completely agree"). There is a maximum total score of 100, with higher scores indicating more fear-avoidance. Five fear-avoidance-related severity levels have been proposed: subclinical (0 to 20), mild (21 to 40), moderate (41 to 60), severe (61 to 80), and extreme (81 to 100).	6 weeks after THA
Other	Fear-Avoidance Component Scale (FACS)	Pain-related fear avoidance was assessed by the Dutch version of the FACS, which is a 20-item questionnaire, with each item scored on a 6-point Likert scale, resulting in scores ranging from zero ("completely disagree") to five ("completely agree"). There is a maximum total score of 100, with higher scores indicating more fear-avoidance. Five fear-avoidance-related severity levels have been proposed: subclinical (0 to 20), mild (21 to 40), moderate (41 to 60), severe (61 to 80), and extreme (81 to 100).	3 months after THA
Other	Fear-Avoidance Component Scale (FACS)	Pain-related fear avoidance was assessed by the Dutch version of the FACS, which is a 20-item questionnaire, with each item scored on a 6-point Likert scale, resulting in scores ranging from zero ("completely disagree") to five ("completely agree"). There is a maximum total score of 100, with higher scores indicating more fear-avoidance. Five fear-avoidance-related severity levels have been proposed: subclinical (0 to 20), mild (21 to 40), moderate (41 to 60), severe (61 to 80), and extreme (81 to 100).	12 months after THA
Other	Tampa Scale for Kinesiophobia (TSK-17)	Pain-related fear of movement was assessed with the 17-item version of the TSK. Each item is scored on a 4-point Likert Scale, ranging from one ("strongly disagree") to four ("strongly agree"). The total score ranges between 17 and 68, with higher values reflecting greater fear of movement.	1 week before THA
Other	Tampa Scale for Kinesiophobia (TSK-17)	Pain-related fear of movement was assessed with the 17-item version of the TSK. Each item is scored on a 4-point Likert Scale, ranging from one ("strongly disagree") to four ("strongly agree"). The total score ranges between 17 and 68, with higher values reflecting greater fear of movement.	1 week after THA
Other	Tampa Scale for Kinesiophobia (TSK-17)	Pain-related fear of movement was assessed with the 17-item version of the TSK. Each item is scored on a 4-point Likert Scale, ranging from one ("strongly disagree") to four ("strongly agree"). The total score ranges between 17 and 68, with higher values reflecting greater fear of movement.	6 weeks after THA
Other	Tampa Scale for Kinesiophobia (TSK-17)	Pain-related fear of movement was assessed with the 17-item version of the TSK. Each item is scored on a 4-point Likert Scale, ranging from one ("strongly disagree") to four ("strongly agree"). The total score ranges between 17 and 68, with higher values reflecting greater fear of movement.	3 months after THA
Other	Tampa Scale for Kinesiophobia (TSK-17)	Pain-related fear of movement was assessed with the 17-item version of the TSK. Each item is scored on a 4-point Likert Scale, ranging from one ("strongly disagree") to four ("strongly agree"). The total score ranges between 17 and 68, with higher values reflecting greater fear of movement.	12 months after THA
Other	Injustice Experience Questionnaire (IEQ)	Perceived injustice was measured with the Injustice Experience Questionnaire (IEQ). The IEQ consists of 12 items, each item is scored from zero ("not at all") to four (all the time"). The total score ranges between 0 and 48 and higher total scores reflect higher levels of perceived injustice.	1 week before THA
Other	Injustice Experience Questionnaire (IEQ)	Perceived injustice was measured with the Injustice Experience Questionnaire (IEQ). The IEQ consists of 12 items, each item is scored from zero ("not at all") to four (all the time"). The total score ranges between 0 and 48 and higher total scores reflect higher levels of perceived injustice.	1 week after THA
Other	Injustice Experience Questionnaire (IEQ)	Perceived injustice was measured with the Injustice Experience Questionnaire (IEQ). The IEQ consists of 12 items, each item is scored from zero ("not at all") to four (all the time"). The total score ranges between 0 and 48 and higher total scores reflect higher levels of perceived injustice.	6 weeks after THA
Other	Injustice Experience Questionnaire (IEQ)	Perceived injustice was measured with the Injustice Experience Questionnaire (IEQ). The IEQ consists of 12 items, each item is scored from zero ("not at all") to four (all the time"). The total score ranges between 0 and 48 and higher total scores reflect higher levels of perceived injustice.	3 months after THA
Other	Injustice Experience Questionnaire (IEQ)	Perceived injustice was measured with the Injustice Experience Questionnaire (IEQ). The IEQ consists of 12 items, each item is scored from zero ("not at all") to four (all the time"). The total score ranges between 0 and 48 and higher total scores reflect higher levels of perceived injustice.	12 months after THA
Other	General Self-Efficacy Scale (GSES)	The General Self-Efficacy Scale is a self-reported questionnaire used to measure self-efficacy. The GSES measures how a person generally copes with stressors/difficult situations in life. It consists of ten statements (optimistic "self-beliefs") that ask about how people think and act in general. Items are scored on a 4-point Likert scale.	1 week before THA
Other	General Self-Efficacy Scale (GSES)	The General Self-Efficacy Scale is a self-reported questionnaire used to measure self-efficacy. The GSES measures how a person generally copes with stressors/difficult situations in life. It consists of ten statements (optimistic "self-beliefs") that ask about how people think and act in general. Items are scored on a 4-point Likert scale.	6 weeks after THA
Other	General Self-Efficacy Scale (GSES)	The General Self-Efficacy Scale is a self-reported questionnaire used to measure self-efficacy. The GSES measures how a person generally copes with stressors/difficult situations in life. It consists of ten statements (optimistic "self-beliefs") that ask about how people think and act in general. Items are scored on a 4-point Likert scale.	3 months after THA
Other	General Self-Efficacy Scale (GSES)	The General Self-Efficacy Scale is a self-reported questionnaire used to measure self-efficacy. The GSES measures how a person generally copes with stressors/difficult situations in life. It consists of ten statements (optimistic "self-beliefs") that ask about how people think and act in general. Items are scored on a 4-point Likert scale.	12 months after THA
Other	Groningen Orthopaedic Social Support Scale (GO-SSS)	The 'Groningen Orthopedic Social Support Scale' is a self-reported questionnaire that has been developed to measure social support in patients with a THA or TKP. Social support is measured through 12 statements where the patient can choose from four answers: 'never or rarely', 'occasionally', 'regularly' or 'often'.	1 week before THA
Other	Groningen Orthopaedic Social Support Scale (GO-SSS)	The 'Groningen Orthopedic Social Support Scale' is a self-reported questionnaire that has been developed to measure social support in patients with a THA or TKP. Social support is measured through 12 statements where the patient can choose from four answers: 'never or rarely', 'occasionally', 'regularly' or 'often'.	6 weeks after THA
Other	Groningen Orthopaedic Social Support Scale (GO-SSS)	The 'Groningen Orthopedic Social Support Scale' is a self-reported questionnaire that has been developed to measure social support in patients with a THA or TKP. Social support is measured through 12 statements where the patient can choose from four answers: 'never or rarely', 'occasionally', 'regularly' or 'often'.	3 months after THA
Other	Groningen Orthopaedic Social Support Scale (GO-SSS)	The 'Groningen Orthopedic Social Support Scale' is a self-reported questionnaire that has been developed to measure social support in patients with a THA or TKP. Social support is measured through 12 statements where the patient can choose from four answers: 'never or rarely', 'occasionally', 'regularly' or 'often'.	12 months after THA
Other	Muscle strength	Hip muscle strength will be measured with the MicroFet 2®, a handheld dynamometer. In the test protocol, each muscle group will be tested three times, with the best value of the three tests as the final result. The following muscle groups will be tested: Hip flexors; Hip abductors; Hip extensors; Hip external rotators; Hip adductors	1 week before THA
Other	Muscle strength	Hip muscle strength will be measured with the MicroFet 2®, a handheld dynamometer. In the test protocol, each muscle group will be tested three times, with the best value of the three tests as the final result. The following muscle groups will be tested: Hip flexors; Hip abductors; Hip extensors; Hip external rotators; Hip adductors	6 weeks after THA
Other	Muscle strength	Hip muscle strength will be measured with the MicroFet 2®, a handheld dynamometer. In the test protocol, each muscle group will be tested three times, with the best value of the three tests as the final result. The following muscle groups will be tested: Hip flexors; Hip abductors; Hip extensors; Hip external rotators; Hip adductors	3 months after THA
Other	Muscle strength	Hip muscle strength will be measured with the MicroFet 2®, a handheld dynamometer. In the test protocol, each muscle group will be tested three times, with the best value of the three tests as the final result. The following muscle groups will be tested: Hip flexors; Hip abductors; Hip extensors; Hip external rotators; Hip adductors	12 months after THA
Other	Perceived stress	Perceived stress will be evaluated with a single question of the Perceived Stress Scale (PSS): 'During the past day, how often have you felt nervous and stressed?'. The question is scored on a 5-point Likert scale, from 0 'never' to 4 'very often'.	1 week before THA
Other	Perceived stress	Perceived stress will be evaluated with a single question of the Perceived Stress Scale (PSS): 'During the past day, how often have you felt nervous and stressed?'. The question is scored on a 5-point Likert scale, from 0 'never' to 4 'very often'.	1 day after THA
Other	Perceived stress	Perceived stress will be evaluated with a single question of the Perceived Stress Scale (PSS): 'During the past day, how often have you felt nervous and stressed?'. The question is scored on a 5-point Likert scale, from 0 'never' to 4 'very often'.	3 days after THA
Other	Perceived stress	Perceived stress will be evaluated with a single question of the Perceived Stress Scale (PSS): 'During the past day, how often have you felt nervous and stressed?'. The question is scored on a 5-point Likert scale, from 0 'never' to 4 'very often'.	5 days after THA
Other	Perceived stress	Perceived stress will be evaluated with a single question of the Perceived Stress Scale (PSS): 'During the past day, how often have you felt nervous and stressed?'. The question is scored on a 5-point Likert scale, from 0 'never' to 4 'very often'.	7 days after THA
Other	Perceived stress	Perceived stress will be evaluated with a single question of the Perceived Stress Scale (PSS): 'During the past day, how often have you felt nervous and stressed?'. The question is scored on a 5-point Likert scale, from 0 'never' to 4 'very often'.	6 weeks after THA
Other	Perceived stress	Perceived stress will be evaluated with a single question of the Perceived Stress Scale (PSS): 'During the past day, how often have you felt nervous and stressed?'. The question is scored on a 5-point Likert scale, from 0 'never' to 4 'very often'.	3 months after THA
Other	Perceived stress	Perceived stress will be evaluated with a single question of the Perceived Stress Scale (PSS): 'During the past day, how often have you felt nervous and stressed?'. The question is scored on a 5-point Likert scale, from 0 'never' to 4 'very often'.	12 months after THA
Primary	Hip disability and Osteoarthritis Outcome Score (HOOS)	The HOOS is a self-reported questionnaire for evaluating symptoms and disability in patients with hip complaints. The questionnaire has been validated in Dutch and consists of 40 items, divided into five subscales: symptoms (5 items), pain (10 items), functioning in activities of daily living (ADL)(17 items), functioning in sport and recreation (4 items), and quality of life (4 items). Each question is scored on a 5-point Likert scale, in which a higher score reflects fewer complaints. A normalized score from 0 to 100 is calculated for the total scale, and for each subscale individually.	1 week before THA
Primary	Hip disability and Osteoarthritis Outcome Score (HOOS)	The HOOS is a self-reported questionnaire for evaluating symptoms and disability in patients with hip complaints. The questionnaire has been validated in Dutch and consists of 40 items, divided into five subscales: symptoms (5 items), pain (10 items), functioning in activities of daily living (ADL)(17 items), functioning in sport and recreation (4 items), and quality of life (4 items). Each question is scored on a 5-point Likert scale, in which a higher score reflects fewer complaints. A normalized score from 0 to 100 is calculated for the total scale, and for each subscale individually.	6 weeks after THA
Primary	Hip disability and Osteoarthritis Outcome Score (HOOS)	The HOOS is a self-reported questionnaire for evaluating symptoms and disability in patients with hip complaints. The questionnaire has been validated in Dutch and consists of 40 items, divided into five subscales: symptoms (5 items), pain (10 items), functioning in activities of daily living (ADL)(17 items), functioning in sport and recreation (4 items), and quality of life (4 items). Each question is scored on a 5-point Likert scale, in which a higher score reflects fewer complaints. A normalized score from 0 to 100 is calculated for the total scale, and for each subscale individually.	3 months after THA
Primary	Hip disability and Osteoarthritis Outcome Score (HOOS)	The HOOS is a self-reported questionnaire for evaluating symptoms and disability in patients with hip complaints. The questionnaire has been validated in Dutch and consists of 40 items, divided into five subscales: symptoms (5 items), pain (10 items), functioning in activities of daily living (ADL)(17 items), functioning in sport and recreation (4 items), and quality of life (4 items). Each question is scored on a 5-point Likert scale, in which a higher score reflects fewer complaints. A normalized score from 0 to 100 is calculated for the total scale, and for each subscale individually.	12 months after THA
Secondary	Patient Specific Functional Scale (PSFS)	The PSFS measures the functional status of the patient. The patient is asked to name the three most important activities for him that are difficult for him or which he is unable to perform because of his problems. Finally, the patient scores the degree of impairment in the activities on an 11-point NRS scale (0-10), where 0 stands for 'cannot perform the activity' and 10 'can perform the activity just as well as before occurrence of the problem'.	1 week before THA
Secondary	Patient Specific Functional Scale (PSFS)	The PSFS measures the functional status of the patient. The patient is asked to name the three most important activities for him that are difficult for him or which he is unable to perform because of his problems. Finally, the patient scores the degree of impairment in the activities on an 11-point NRS scale (0-10), where 0 stands for 'cannot perform the activity' and 10 'can perform the activity just as well as before occurrence of the problem'.	6 weeks after THA
Secondary	Patient Specific Functional Scale (PSFS)	The PSFS measures the functional status of the patient. The patient is asked to name the three most important activities for him that are difficult for him or which he is unable to perform because of his problems. Finally, the patient scores the degree of impairment in the activities on an 11-point NRS scale (0-10), where 0 stands for 'cannot perform the activity' and 10 'can perform the activity just as well as before occurrence of the problem'.	3 months after THA
Secondary	Patient Specific Functional Scale (PSFS)	The PSFS measures the functional status of the patient. The patient is asked to name the three most important activities for him that are difficult for him or which he is unable to perform because of his problems. Finally, the patient scores the degree of impairment in the activities on an 11-point NRS scale (0-10), where 0 stands for 'cannot perform the activity' and 10 'can perform the activity just as well as before occurrence of the problem'.	12 months after THA
Secondary	36-Item Short Form Health Survey (SF-36)	The SF-36 is used to measure perceived health and health-related quality of life. The questionnaire has 36 items containing eight health-related categories: physical functioning, role limitations due to physical problems, role limitations due to emotional problems, pain, mental health, energy, general health perception, and social functioning. A high score corresponds to a better state of health.	1 week before THA
Secondary	36-Item Short Form Health Survey (SF-36)	The SF-36 is used to measure perceived health and health-related quality of life. The questionnaire has 36 items containing eight health-related categories: physical functioning, role limitations due to physical problems, role limitations due to emotional problems, pain, mental health, energy, general health perception, and social functioning. A high score corresponds to a better state of health.	6 weeks after THA
Secondary	36-Item Short Form Health Survey (SF-36)	The SF-36 is used to measure perceived health and health-related quality of life. The questionnaire has 36 items containing eight health-related categories: physical functioning, role limitations due to physical problems, role limitations due to emotional problems, pain, mental health, energy, general health perception, and social functioning. A high score corresponds to a better state of health.	3 months after THA
Secondary	36-Item Short Form Health Survey (SF-36)	The SF-36 is used to measure perceived health and health-related quality of life. The questionnaire has 36 items containing eight health-related categories: physical functioning, role limitations due to physical problems, role limitations due to emotional problems, pain, mental health, energy, general health perception, and social functioning. A high score corresponds to a better state of health.	12 months after THA
Secondary	Global Perceived Effect (GPE)	The patient's opinion about recovery after THA will be measured using the Global Perceived Effect (GPE) score on a 7-point Likert scale, where 1 stands for "a lot worse" and 7 for "a lot better".	1 day after THA
Secondary	Global Perceived Effect (GPE)	The patient's opinion about recovery after THA will be measured using the Global Perceived Effect (GPE) score on a 7-point Likert scale, where 1 stands for "a lot worse" and 7 for "a lot better".	3 days after THA
Secondary	Global Perceived Effect (GPE)	The patient's opinion about recovery after THA will be measured using the Global Perceived Effect (GPE) score on a 7-point Likert scale, where 1 stands for "a lot worse" and 7 for "a lot better".	5 days after THA
Secondary	Global Perceived Effect (GPE)	The patient's opinion about recovery after THA will be measured using the Global Perceived Effect (GPE) score on a 7-point Likert scale, where 1 stands for "a lot worse" and 7 for "a lot better".	7 days after THA
Secondary	Global Perceived Effect (GPE)	The patient's opinion about recovery after THA will be measured using the Global Perceived Effect (GPE) score on a 7-point Likert scale, where 1 stands for "a lot worse" and 7 for "a lot better".	6 weeks after THA
Secondary	Global Perceived Effect (GPE)	The patient's opinion about recovery after THA will be measured using the Global Perceived Effect (GPE) score on a 7-point Likert scale, where 1 stands for "a lot worse" and 7 for "a lot better".	3 months after THA
Secondary	Global Perceived Effect (GPE)	The patient's opinion about recovery after THA will be measured using the Global Perceived Effect (GPE) score on a 7-point Likert scale, where 1 stands for "a lot worse" and 7 for "a lot better".	12 months after THA
Secondary	Numerical Rating Scale (NRS) of Patient Satisfaction	Patient satisfaction will be measured on an 11-point Numerical Rating Scale (NRS), where 0 stands for "no pain" and 10 for "worst imaginable pain".	1 day after THA
Secondary	Numerical Rating Scale (NRS) of Patient Satisfaction	Patient satisfaction will be measured on an 11-point Numerical Rating Scale (NRS), where 0 stands for "no pain" and 10 for "worst imaginable pain".	3 days after THA
Secondary	Numerical Rating Scale (NRS) of Patient Satisfaction	Patient satisfaction will be measured on an 11-point Numerical Rating Scale (NRS), where 0 stands for "no pain" and 10 for "worst imaginable pain".	5 days after THA
Secondary	Numerical Rating Scale (NRS) of Patient Satisfaction	Patient satisfaction will be measured on an 11-point Numerical Rating Scale (NRS), where 0 stands for "no pain" and 10 for "worst imaginable pain".	7 days after THA
Secondary	Numerical Rating Scale (NRS) of Patient Satisfaction	Patient satisfaction will be measured on an 11-point Numerical Rating Scale (NRS), where 0 stands for "no pain" and 10 for "worst imaginable pain".	6 weeks after THA
Secondary	Numerical Rating Scale (NRS) of Patient Satisfaction	Patient satisfaction will be measured on an 11-point Numerical Rating Scale (NRS), where 0 stands for "no pain" and 10 for "worst imaginable pain".	3 months after THA
Secondary	Numerical Rating Scale (NRS) of Patient Satisfaction	Patient satisfaction will be measured on an 11-point Numerical Rating Scale (NRS), where 0 stands for "no pain" and 10 for "worst imaginable pain".	12 months after THA
Secondary	Numerical Pain Rating Scale (NPRS)	Average pain intensity last week and pain intensity at the moment will be measured on an 11-point Numerical Pain Rating Scale (NPRS), where 0 stands for "no pain" and 10 for "worst imaginable pain".	1 week before THA
Secondary	Numerical Pain Rating Scale (NPRS)	Average pain intensity last week and pain intensity at the moment will be measured on an 11-point Numerical Pain Rating Scale (NPRS), where 0 stands for "no pain" and 10 for "worst imaginable pain".	1 day after THA
Secondary	Numerical Pain Rating Scale (NPRS)	Average pain intensity last week and pain intensity at the moment will be measured on an 11-point Numerical Pain Rating Scale (NPRS), where 0 stands for "no pain" and 10 for "worst imaginable pain".	3 days after THA
Secondary	Numerical Pain Rating Scale (NPRS)	Average pain intensity last week and pain intensity at the moment will be measured on an 11-point Numerical Pain Rating Scale (NPRS), where 0 stands for "no pain" and 10 for "worst imaginable pain".	5 days after THA
Secondary	Numerical Pain Rating Scale (NPRS)	Average pain intensity last week and pain intensity at the moment will be measured on an 11-point Numerical Pain Rating Scale (NPRS), where 0 stands for "no pain" and 10 for "worst imaginable pain".	7 days after THA
Secondary	Numerical Pain Rating Scale (NPRS)	Average pain intensity last week and pain intensity at the moment will be measured on an 11-point Numerical Pain Rating Scale (NPRS), where 0 stands for "no pain" and 10 for "worst imaginable pain".	6 weeks after THA
Secondary	Numerical Pain Rating Scale (NPRS)	Average pain intensity last week and pain intensity at the moment will be measured on an 11-point Numerical Pain Rating Scale (NPRS), where 0 stands for "no pain" and 10 for "worst imaginable pain".	3 months after THA
Secondary	Numerical Pain Rating Scale (NPRS)	Average pain intensity last week and pain intensity at the moment will be measured on an 11-point Numerical Pain Rating Scale (NPRS), where 0 stands for "no pain" and 10 for "worst imaginable pain".	12 months after THA
Secondary	30-second Chair Stand Test	The 30-second Chair Stand Test will be used to assess sit-to-stand activity (physical function). The maximum number of chair stand repetitions within 30 seconds will be used as the outcome value. Movement quality during the performance-based tests is assessed based on acceleration data measured with an Inertial Measurement Unit (IMU).	1 week before THA
Secondary	30-second Chair Stand Test	The 30-second Chair Stand Test will be used to assess sit-to-stand activity (physical function). The maximum number of chair stand repetitions within 30 seconds will be used as the outcome value. Movement quality during the performance-based tests is assessed based on acceleration data measured with an Inertial Measurement Unit (IMU).	6 weeks after THA
Secondary	30-second Chair Stand Test	The 30-second Chair Stand Test will be used to assess sit-to-stand activity (physical function). The maximum number of chair stand repetitions within 30 seconds will be used as the outcome value. Movement quality during the performance-based tests is assessed based on acceleration data measured with an Inertial Measurement Unit (IMU).	3 months after THA
Secondary	30-second Chair Stand Test	The 30-second Chair Stand Test will be used to assess sit-to-stand activity (physical function). The maximum number of chair stand repetitions within 30 seconds will be used as the outcome value. Movement quality during the performance-based tests is assessed based on acceleration data measured with an Inertial Measurement Unit (IMU).	12 months after THA
Secondary	11-step Stair Climb Test	The 11-step Stair Climb Test will be used to assess ascending and descending stair activity (physical function). The time in seconds to ascend and descend 11 stairs will be used as the outcome value. Movement quality during the performance-based tests is assessed based on acceleration data measured with an Inertial Measurement Unit (IMU).	1 week before THA
Secondary	11-step Stair Climb Test	The 11-step Stair Climb Test will be used to assess ascending and descending stair activity (physical function). The time in seconds to ascend and descend 11 stairs will be used as the outcome value. Movement quality during the performance-based tests is assessed based on acceleration data measured with an Inertial Measurement Unit (IMU).	6 weeks after THA
Secondary	11-step Stair Climb Test	The 11-step Stair Climb Test will be used to assess ascending and descending stair activity (physical function). The time in seconds to ascend and descend 11 stairs will be used as the outcome value. Movement quality during the performance-based tests is assessed based on acceleration data measured with an Inertial Measurement Unit (IMU).	3 months after THA
Secondary	11-step Stair Climb Test	The 11-step Stair Climb Test will be used to assess ascending and descending stair activity (physical function). The time in seconds to ascend and descend 11 stairs will be used as the outcome value. Movement quality during the performance-based tests is assessed based on acceleration data measured with an Inertial Measurement Unit (IMU).	12 months after THA
Secondary	40-meter (4x10-meter) Fast Paced Walk Test	The 40-meter (4x10-meter) Fast Paced Walk Test will be used to assess short distance walking activity (physical function). The time in seconds to walk 4 x 10 meters for a total of 40 meters will be used as the outcome value. Movement quality during the performance-based tests is assessed based on acceleration data measured with an Inertial Measurement Unit (IMU).	1 week before THA
Secondary	40-meter (4x10-meter) Fast Paced Walk Test	The 40-meter (4x10-meter) Fast Paced Walk Test will be used to assess short distance walking activity (physical function). The time in seconds to walk 4 x 10 meters for a total of 40 meters will be used as the outcome value. Movement quality during the performance-based tests is assessed based on acceleration data measured with an Inertial Measurement Unit (IMU).	6 weeks after THA
Secondary	40-meter (4x10-meter) Fast Paced Walk Test	The 40-meter (4x10-meter) Fast Paced Walk Test will be used to assess short distance walking activity (physical function). The time in seconds to walk 4 x 10 meters for a total of 40 meters will be used as the outcome value. Movement quality during the performance-based tests is assessed based on acceleration data measured with an Inertial Measurement Unit (IMU).	3 months after THA
Secondary	40-meter (4x10-meter) Fast Paced Walk Test	The 40-meter (4x10-meter) Fast Paced Walk Test will be used to assess short distance walking activity (physical function). The time in seconds to walk 4 x 10 meters for a total of 40 meters will be used as the outcome value. Movement quality during the performance-based tests is assessed based on acceleration data measured with an Inertial Measurement Unit (IMU).	12 months after THA