Chronic Post Surgical PainNCT07673276
Incidence of Chronic Pain in Patients Undergoing Knee Arthroplasty Within a Fast-Track Protocol
An observational study of Chronic Post Surgical Pain and Functional Recovery, run by University Hospital, Ghent at 1 site in Belgium.
Trial summary
The goal of this study is to learn about pain after knee replacement surgery. The surgery uses a fast-recovery program called Enhanced Recovery After Surgery (ERAS). The main questions are: How many participants still have pain three months after surgery? How severe is the pain? How many participants still use strong… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Chronic Post Surgical Pain, Functional Recovery, ERAS
- How many people
- 153 participants
- Where
- 1 siteBelgium
- Study dates
- 24 Feb 2025to 1 Jul 2026
- How long will I take part?
- 3 Months
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: All patients for whom a knee replacement is planned by a surgeon at our hospital and who are eligible for the fast-track program.
Who may be able to join
- All patients suitable for a standardized approach to the primary elective knee arthroplasty surgery and recovery period.
Who cannot join
- Significant comorbidities that may cause complications during the operation or the recovery period (e.g., heart and lung diseases, severe kidney disease, severe overweight).
- Severe neurological, physical, mental, and/or cognitive conditions that may complicate rehabilitation (e.g., inability to understand or follow postoperative instructions).
- Active infections or septic arthritis.
- Specific surgical obstacles such as revision surgery, extensive previous joint surgery, severe limitations in movement, severe instability, or marked abnormalities.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Incidence of Chronic Pain in Patients Undergoing Knee Arthroplasty Within a Fast-Track Protocol: A Prospective Cohort Study
The goal of this study is to learn about pain after knee replacement surgery. The surgery uses a fast-recovery program called Enhanced Recovery After Surgery (ERAS).
The main questions are:
Read more
How many participants still have pain three months after surgery? How severe is the pain? How many participants still use strong pain medication (opioids)? Participants are adults undergoing knee replacement surgery at UZ Gent and following the ERAS program.
Researchers will collect information on pain and recovery before surgery and for up to three months afterward. Participants will answer simple questions about their pain and daily activities.
This study will help researchers understand post-surgical recovery and may help improve pain care in the future.
Read the detailed description
This prospective observational cohort study evaluates perioperative pain management and recovery outcomes in adult patients undergoing primary knee replacement surgery within an Enhanced Recovery After Surgery (ERAS), or fast-track, pathway at UZ Gent.
Knee arthroplasty is an established surgical intervention for patients with advanced joint disease, with the aim of improving mobility and reducing pain. The ERAS pathway integrates standardized perioperative care elements, including optimized anesthesia, multimodal analgesia, early mobilization, and reduced length of hospital stay. While ERAS protocols have demonstrated benefits regarding recovery and hospital discharge, the effect of these pathways on persistent postoperative pain and opioid use requires further evaluation.
Persistent pain after knee replacement surgery remains an important clinical outcome. A proportion of patients experience ongoing pain or functional limitations despite technically successful surgery.
Patients included in this study will undergo knee replacement surgery according to the institutional ERAS protocol. The protocol includes preoperative assessment, standardized perioperative care, and early postoperative mobilization. Suitability for the ERAS pathway is evaluated during the preoperative anesthesia consultation. Any deviations from the standardized pathway, including changes in perioperative management or rehabilitation, will be documented together with the reason for the deviation.
Patients undergoing knee replacement surgery according to the ERAS pathway will be followed prospectively from the preoperative assessment until three months after surgery. Data collected will include perioperative characteristics, pain scores, functional outcomes, neuropathic pain features, opioid use, and relevant clinical variables.
Clinical data will be collected prospectively from the preoperative period until three months after surgery. Pain outcomes will be assessed at predefined time points using validated pain assessment tools. Information regarding pain intensity, functional recovery, neuropathic pain characteristics, and opioid medication use will be collected. Additional perioperative variables, including patient characteristics, anesthesia technique, surgical technique, and relevant medical history, will be recorded.
The study population consists of approximately 120 patients undergoing primary elective knee arthroplasty over a one-year inclusion period. Patients who are not considered suitable for the standardized ERAS approach because of relevant medical, neurological, physical, cognitive, surgical, or rehabilitation-related factors will not be included.
The collected data will be analyzed to describe the occurrence and characteristics of persistent postoperative pain after knee replacement surgery within an ERAS pathway. Descriptive analyses will summarize patient characteristics, pain outcomes, opioid use, and recovery measures. Exploratory analyses will evaluate potential associations between perioperative factors and persistent postoperative pain.
As ERAS has become the standard of care at the institution, comparison with a conventional-care control group is not planned. Instead, findings from this cohort will be interpreted in relation to previously published data from conventional perioperative care pathways.
This study aims to provide clinical insight into pain recovery after knee arthroplasty within an ERAS program and may contribute to improving postoperative pain management and patient follow-up strategies.
- Conditions
- Chronic Post Surgical Pain, Functional Recovery, ERAS, Chronic Opioid Use, Inthrathecal Morfine, Knee Arthroplasty
- Keywords
- ERAS, CPSP, Functional recovery, Knee Arthroplasty
- Medical subject headings
- Pain, Postoperative
What is being measured
The primary outcome is the main question the study is designed to answer.
Chronic postoperative pain (CPSP) at three months after knee arthroplasty
Pain intensity will be assessed using the Numeric Rating Scale (NRS) during movement. CPSP will be defined as an NRS score ≥4 at three months postoperatively. Severe chronic postoperative pain will be defined as an NRS score ≥6.
Unit of Measure:
Points on an 0-10 Numeric Rating Scale.
Measured: Three months after knee arthroplasty
Functional recovery at 3 months after knee replacement
Functional recovery will be assessed using the Oxford Knee Score (OKS). A score ≤14 indicates a poor functional outcome related to knee pain.
Unit of Measure:
Points on the Oxford Knee Score (0-48)
Measured: 3 months postoperatively
Neuropathic pain characteristics at 3 months
Neuropathic pain features will be evaluated using the DN4 questionnaire. A DN4 score ≥4 is considered suggestive of neuropathic pain. Unit of Measure: Points on the DN4 questionnaire (0-10).
Measured: 3 months postoperatively
Postoperative opioid use at 3 months
Postoperative opioid use will be assessed by recording whether participants use opioid medication and, if applicable, the amount of opioid medication used.
Unit: Number of participants using opioids (yes/no) and/or morphine milligram equivalents (MME).
Measured: 3 months postoperatively
Secondary outcomes (5)
Postoperative pain intensity during hospital stay after knee arthroplasty
Pain intensity will be assessed using the Numeric Rating Scale (NRS) at rest and during movement. Weighted average NRS pain scores will be calculated for postoperative day 1 and day 2. Unit of Measure: Points on an 0-10 Numeric Rating Scale.
Measured: Postoperative day 1 and day 2 after knee arthroplasty
Preoperative and discharge pain intensity after knee arthroplasty
Pain intensity will be assessed using the Numeric Rating Scale (NRS) at rest and during movement before surgery and at hospital discharge. Unit of Measure:
Points on an 0-10 Numeric Rating Scale.
Measured: Preoperatively and at postoperative day 1-2-3-4 (at hospital discharge)
Opioid consumption during the perioperative period
Opioid pain medication use will be recorded before surgery and during hospital stay. Opioid consumption will be converted into morphine milligram equivalents (MME) and reported as a weighted average per day. Unit of Measure: Morphine milligram equivalents (MME/day).
Measured: Perioperative period through postoperative day 1-2-3 (at hospital discharge)
Surgical complications after knee arthroplasty
Surgical complications will be identified from medical records and surgical documentation. Unit of Measure: Number and percentage of participants with complications.
Measured: From surgery until three months postoperatively
Length of hospital stay after knee arthroplasty
Hospital stay will be calculated from the day of surgery until discharge. Unit of Measure: Days.
Measured: Postoperative day 1-2-3-4
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Jun 2026
- Study start24 Feb 2025
- Primary completion1 Jul 2026 (estimated)
- Study completion1 Jul 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Chronic Post Surgical PainStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 153 participants (actual)
- Target duration
- 3 Months
Sponsor and investigators
- Lead sponsor
- University Hospital, Ghent
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Patrick Wouters, Prof. Dr., Study chair, University Hospital, Ghent
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07673276
- Sponsor's protocol ID
- ONZ-2024-0360
- Other IDs
- 19288
- Status last verified
- Jun 2026
- First submitted
- 15 May 2026
- Last updated
- 29 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 29 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Incidence of Chronic Pain in Patients Undergoing Knee Arthroplasty Within a Fast-Track Protocol: A Prospective Cohort Study
- ClinicalTrials.gov ID
- NCT07673276
- Acronym / sponsor ID
- ONZ-2024-0360
- Conditions
- Chronic Post Surgical Pain, Functional Recovery, ERAS, Chronic Opioid Use, Inthrathecal Morfine, Knee Arthroplasty
- Keywords
- ERAS, CPSP, Functional recovery, Knee Arthroplasty
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 153 participants (actual)
- Lead sponsor
- University Hospital, GhentUniversity, hospital or other
- Study start
- 24 Feb 2025 (actual)
- Primary completion
- 1 Jul 2026 (estimated)
- Study completion
- 1 Jul 2026 (estimated)
- First posted
- 29 Jun 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this study is to learn about pain after knee replacement surgery. The surgery uses a fast-recovery program called Enhanced Recovery After Surgery (ERAS).
The main questions are:
How many participants still have pain three months after surgery? How severe is the pain? How many participants still use strong pain medication (opioids)? Participants are adults undergoing knee replacement surgery at UZ Gent and following the ERAS program.
Researchers will collect information on pain and recovery before surgery and for up to three months afterward. Participants will answer simple questions about their pain and daily activities.
This study will help researchers understand post-surgical recovery and may help improve pain care in the future.
Detailed description
This prospective observational cohort study evaluates perioperative pain management and recovery outcomes in adult patients undergoing primary knee replacement surgery within an Enhanced Recovery After Surgery (ERAS), or fast-track, pathway at UZ Gent.
Knee arthroplasty is an established surgical intervention for patients with advanced joint disease, with the aim of improving mobility and reducing pain. The ERAS pathway integrates standardized perioperative care elements, including optimized anesthesia, multimodal analgesia, early mobilization, and reduced length of hospital stay. While ERAS protocols have demonstrated benefits regarding recovery and hospital discharge, the effect of these pathways on persistent postoperative pain and opioid use requires further evaluation.
Persistent pain after knee replacement surgery remains an important clinical outcome. A proportion of patients experience ongoing pain or functional limitations despite technically successful surgery.
Patients included in this study will undergo knee replacement surgery according to the institutional ERAS protocol. The protocol includes preoperative assessment, standardized perioperative care, and early postoperative mobilization. Suitability for the ERAS pathway is evaluated during the preoperative anesthesia consultation. Any deviations from the standardized pathway, including changes in perioperative management or rehabilitation, will be documented together with the reason for the deviation.
Patients undergoing knee replacement surgery according to the ERAS pathway will be followed prospectively from the preoperative assessment until three months after surgery. Data collected will include perioperative characteristics, pain scores, functional outcomes, neuropathic pain features, opioid use, and relevant clinical variables.
Clinical data will be collected prospectively from the preoperative period until three months after surgery. Pain outcomes will be assessed at predefined time points using validated pain assessment tools. Information regarding pain intensity, functional recovery, neuropathic pain characteristics, and opioid medication use will be collected. Additional perioperative variables, including patient characteristics, anesthesia technique, surgical technique, and relevant medical history, will be recorded.
The study population consists of approximately 120 patients undergoing primary elective knee arthroplasty over a one-year inclusion period. Patients who are not considered suitable for the standardized ERAS approach because of relevant medical, neurological, physical, cognitive, surgical, or rehabilitation-related factors will not be included.
The collected data will be analyzed to describe the occurrence and characteristics of persistent postoperative pain after knee replacement surgery within an ERAS pathway. Descriptive analyses will summarize patient characteristics, pain outcomes, opioid use, and recovery measures. Exploratory analyses will evaluate potential associations between perioperative factors and persistent postoperative pain.
As ERAS has become the standard of care at the institution, comparison with a conventional-care control group is not planned. Instead, findings from this cohort will be interpreted in relation to previously published data from conventional perioperative care pathways.
This study aims to provide clinical insight into pain recovery after knee arthroplasty within an ERAS program and may contribute to improving postoperative pain management and patient follow-up strategies.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Target follow-up
- 3 Months
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- All patients for whom a knee replacement is planned by a surgeon at our hospital and who are eligible for the fast-track program.
Key inclusion criteria (1 listed)
- All patients suitable for a standardized approach to the primary elective knee arthroplasty surgery and recovery period.
Key exclusion criteria (4 listed)
- Significant comorbidities that may cause complications during the operation or the recovery period (e.g., heart and lung diseases, severe kidney disease, severe overweight).
- Severe neurological, physical, mental, and/or cognitive conditions that may complicate rehabilitation (e.g., inability to understand or follow postoperative instructions).
- Active infections or septic arthritis.
- Specific surgical obstacles such as revision surgery, extensive previous joint surgery, severe limitations in movement, severe instability, or marked abnormalities.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Chronic postoperative pain (CPSP) at three months after knee arthroplasty
Time frame: Three months after knee arthroplasty
Pain intensity will be assessed using the Numeric Rating Scale (NRS) during movement. CPSP will be defined as an NRS score ≥4 at three months postoperatively. Severe chronic postoperative pain will be defined as an NRS score ≥6. Unit of Measure: Points on an 0-10 Numeric Rating Scale.
Functional recovery at 3 months after knee replacement
Time frame: 3 months postoperatively
Functional recovery will be assessed using the Oxford Knee Score (OKS). A score ≤14 indicates a poor functional outcome related to knee pain. Unit of Measure: Points on the Oxford Knee Score (0-48)
Neuropathic pain characteristics at 3 months
Time frame: 3 months postoperatively
Neuropathic pain features will be evaluated using the DN4 questionnaire. A DN4 score ≥4 is considered suggestive of neuropathic pain. Unit of Measure: Points on the DN4 questionnaire (0-10).
Postoperative opioid use at 3 months
Time frame: 3 months postoperatively
Postoperative opioid use will be assessed by recording whether participants use opioid medication and, if applicable, the amount of opioid medication used. Unit: Number of participants using opioids (yes/no) and/or morphine milligram equivalents (MME).
5 secondary outcomes
Postoperative pain intensity during hospital stay after knee arthroplasty
Time frame: Postoperative day 1 and day 2 after knee arthroplasty
Preoperative and discharge pain intensity after knee arthroplasty
Time frame: Preoperatively and at postoperative day 1-2-3-4 (at hospital discharge)
Opioid consumption during the perioperative period
Time frame: Perioperative period through postoperative day 1-2-3 (at hospital discharge)
Surgical complications after knee arthroplasty
Time frame: From surgery until three months postoperatively
Length of hospital stay after knee arthroplasty
Time frame: Postoperative day 1-2-3-4
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 29 Jun 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Patrick Wouters, Prof. Dr. study chair
University Hospital, Ghent
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Chronic Post Surgical Pain and Functional Recovery, run by University Hospital, Ghent at 1 site in Belgium.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 29 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Belgium. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Chronic postoperative pain (CPSP) at three months after knee arthroplasty (time frame: Three months after knee arthroplasty). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 29 Jun 2026; AzTrials last refreshed its copy on 26 Oct 2026.