Knee OsteoarthristisNCT07367126
Neuropathic Pain in Knee Osteoarthritis: Pain Severity and Functional Status
An observational study of Knee Osteoarthristis, run by Istanbul Physical Medicine Rehabilitation Training and Research Hospital at 1 site in Turkey (Türkiye).
Trial summary
Osteoarthritis (OA) is a degenerative joint disease characterized by structural changes such as cartilage loss and osteophyte formation, leading to functional limitations and disability. Pain in knee OA involves a complex pathophysiological structure including both nociceptive and neuropathic mechanisms. Read more about this study
- Who is it for?
- Ages 40 to 70 years
- Conditions the study is for
- Knee Osteoarthristis
- What is being tested?
- Clinical and Functional Assessment
- How many people
- 102 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 20 Dec 2025to 30 Apr 2026
- 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 40 to 70 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: The source population for this cross-sectional controlled study is the adult patient population diagnosed with knee osteoarthritis (OA) according to the American College of Rheumatology (ACR) criteria, recruited from the Physical Medicine and Rehabilitation outpatient clinic at Istanbul Physical Therapy and Rehabilitation Training and Research Hospital.
Who may be able to join
- Diagnosed with Knee OA according to ACR criteria.
- Knee pain for more than 3 months.
- Voluntary participation.
Who cannot join
- History of surgical intervention in the affected knee.
- History of trauma to the affected knee within the last 6 months.
- History of intra-articular injections (e.g., corticosteroids, hyaluronic acid, PRP) or physical therapy involving the affected knee within the last 6 months.
- Presence of severe psychiatric disorders such as severe depression, anxiety disorder, or psychosis.
- Diagnosis of central nervous system diseases, including Parkinson's disease or multiple sclerosis.
- Diagnosis of inflammatory arthritis, such as Rheumatoid Arthritis or Ankylosing Spondylitis.
Show all 10Show fewer
- Severe cognitive impairment.
- Chronic decompensated cardiac, renal, or hepatic failure.
- Severe psychiatric, neurological, or kognitive disorders.
- Decompensated cardiac, renal, or hepatic failure.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Turkey (Türkiye)1 site, 1 recruiting
- Recruiting
Istanbul Physical Medicine and Rehabilitation Training and Research Hospital
Istanbul, 34186
Eser Kalaoglu, M.D., +90 (212) 496 50 00 ext. 2126, eserkalaoglu@hotmail.com
About this study
Official title: Presence of Neuropathic Pain in Knee Osteoarthritis: Relationship Between Pain Severity and Functional Status
Osteoarthritis (OA) is a degenerative joint disease characterized by structural changes such as cartilage loss and osteophyte formation, leading to functional limitations and disability. Pain in knee OA involves a complex pathophysiological structure including both nociceptive and neuropathic mechanisms. Identifying the neuropathic pain component is clinically significant for improving quality of life and functional recovery. This cross-sectional controlled clinical study aims to determine the prevalence of neuropathic pain in patients with knee OA and evaluate its impact on pain severity and functional status. Patients will be categorized based on the Douleur Neuropathique 4 (DN4) questionnaire and assessed using various pain and functional scales.
Read the detailed description
Osteoarthritis (OA) is a degenerative joint disease characterized by structural alterations, including focal cartilage loss, osteophyte formation, subchondral sclerosis, and synovitis. Given the growing elderly population, the prevalence of OA is rising, frequently leading to significant functional limitations and disability. Pain, the most prominent symptom of OA, serves as a critical measure for monitoring disease activity and treatment efficacy.
Recent evidence suggests that OA-related pain involves a complex pathophysiological structure, incorporating both nociceptive and neuropathic mechanisms. Studies indicate that approximately 19-37% of patients with knee OA exhibit symptoms consistent with neuropathic pain. Identifying this neuropathic component is clinically essential, as it may respond differently to conventional analgesics; thus, recognizing it is vital for optimizing functional recovery and quality of life.
This cross-sectional controlled clinical trial aims to determine the prevalence of neuropathic pain in patients with knee OA and evaluate its impact on pain severity and functional status. Participants diagnosed with knee OA according to the American College of Rheumatology (ACR) criteria will be recruited and categorized into two groups based on a Douleur Neuropathique 4 (DN4) questionnaire score threshold of 4/10.
For all participants, comprehensive demographic and clinical data, including age, body mass index (BMI), educational level, occupation, and marital status, will be recorded. To ensure consistency and minimize measurement error, all anthropometric assessments will be performed by a single researcher. The following standardized assessment tools will be administered to all participants: Visual Analog Scale (VAS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Knee Injury and Osteoarthritis Outcome Score-Physical Function Short Form (KOOS-PS).
- Conditions
- Knee Osteoarthristis
- Being tested
- Clinical and Functional Assessment
- Keywords
- Pain Intensity, Functional Status, Neuropathic Pain, Knee Osteoarthritis
- Medical subject headings
- Pain, Neuralgia, Osteoarthritis, Knee
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Clinical and Functional AssessmentOther
All participants will undergo a one-time, cross-sectional clinical assessment. Comprehensive demographic and clinical data, including age, body mass index (BMI), educational level, occupation, and marital status, will be recorded for each participant. Pain intensity will be measured using a 10-cm Visual Analog Scale (VAS). Functional status and symptoms related to knee osteoarthritis will be evaluated using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the Knee Injury and Osteoarthritis Outcome Score-Physical Function Short Form (KOOS-PS). To ensure consistency and minimize measurement error, all anthropometric measurements, specifically weight and height, will be performed by the same researcher.
| Study group | Role | What they receive |
|---|---|---|
| Group 1 (Case) | Patients with Knee OA and Neuropathic Pain (DN4 score ≥ 4) Receives: Other: Clinical and Functional Assessment | |
| Group 2 (Control) | Patients with Knee OA without Neuropathic Pain (DN4 score < 4) Receives: Other: Clinical and Functional Assessment |
What is being measured
The primary outcome is the main question the study is designed to answer.
Visual Analog Scale (VAS)
Pain intensity was assessed using a 10 cm scale, where one end represents "no pain" and the other represents "most severe pain." Patients were asked to rate their pain on a scale from 0 (no pain) to 10 (most severe pain)
Measured: at baseline assessment
Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)
Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) consists of subscales evaluating pain (5 items), stiffness (2 items), and physical function (17 items). Using a 5-point Likert scale, scores range from 0 (representing the best status/no pain) to 96 (representing the worst status/extreme pain).
Measured: at baseline assessment
Secondary outcomes (1)
Knee Injury and Osteoarthritis Outcome Score - Physical Function Short Form (KOOS-PS)
Knee Injury and Osteoarthritis Outcome Score - Physical Function Short Form (KOOS-PS) is used to evaluate physical functional limitations associated with knee osteoarthritis. It consists of seven items scored on a 5-point Likert scale. Raw scores are converted to a 0-100 scale, where higher scores indicate better physical function.
Measured: at baseline assessment
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted26 Jan 2026
- Study start20 Dec 2025
- Primary completion31 Mar 2026 (estimated)
- Study completion30 Apr 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (6)Papers the sponsor has linked to this study.
- Other trials for Knee OsteoarthristisStudies 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
- Case-control
- Time perspective
- Cross-sectional
- Enrolment
- 102 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Istanbul Physical Medicine Rehabilitation Training and Research Hospital
- Sponsor type
- Other government
- Responsible party
- Principal investigator, Eser Kalaoglu, Istanbul Physical Medicine Rehabilitation Training and Research Hospital
- Investigators
- Eser Kalaoglu, M.D., Principal investigator, Istanbul Physical Medicine Rehabilitation Training and Research Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07367126
- Sponsor's protocol ID
- İstPRMTRH-EK6
- Status last verified
- Dec 2025
- First submitted
- 17 Jan 2026
- Last updated
- 26 Jan 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: De-identified individual participant data (IPD), including all demographic, clinical, and primary/secondary outcome measures will be shared with qualified researchers. The sharing period will commence 6 months after article publication and conclude 1 year thereafter. Data access requests must be accompanied by a methodologically sound proposal and will be granted upon the corresponding author's approval and the execution of a Data Use Agreement (DUA) to strictly ensure confidentiality and adherence to ethical guidelines.
Publications
Ohtori S, Orita S, Yamashita M, Ishikawa T, Ito T, Shigemura T, Nishiyama H, Konno S, Ohta H, Takaso M, Inoue G, Eguchi Y, Ochiai N, Kishida S, Kuniyoshi K, Aoki Y, Arai G, Miyagi M, Kamoda H, Suzkuki M, Nakamura J, Furuya T, Kubota G, Sakuma Y, Oikawa Y, Suzuki M, Sasho T, Nakagawa K, Toyone T, Takahashi K. Existence of a neuropathic pain component in patients with osteoarthritis of the knee. Yonsei Med J. 2012 Jul 1;53(4):801-5. doi: 10.3349/ymj.2012.53.4.801.
PubMed 22665349Hochman JR, Davis AM, Elkayam J, Gagliese L, Hawker GA. Neuropathic pain symptoms on the modified painDETECT correlate with signs of central sensitization in knee osteoarthritis. Osteoarthritis Cartilage. 2013 Sep;21(9):1236-42. doi: 10.1016/j.joca.2013.06.023.
PubMed 23973136Davis MP. What is new in neuropathic pain? Support Care Cancer. 2007 Apr;15(4):363-72. doi: 10.1007/s00520-006-0156-0. Epub 2006 Nov 28.
PubMed 17131133Treede RD, Jensen TS, Campbell JN, Cruccu G, Dostrovsky JO, Griffin JW, Hansson P, Hughes R, Nurmikko T, Serra J. Neuropathic pain: redefinition and a grading system for clinical and research purposes. Neurology. 2008 Apr 29;70(18):1630-5. doi: 10.1212/01.wnl.0000282763.29778.59. Epub 2007 Nov 14.
PubMed 18003941Perrot S. Osteoarthritis pain. Best Pract Res Clin Rheumatol. 2015 Feb;29(1):90-7. doi: 10.1016/j.berh.2015.04.017. Epub 2015 May 16.
PubMed 26267003Pereira D, Peleteiro B, Araujo J, Branco J, Santos RA, Ramos E. The effect of osteoarthritis definition on prevalence and incidence estimates: a systematic review. Osteoarthritis Cartilage. 2011 Nov;19(11):1270-85. doi: 10.1016/j.joca.2011.08.009. Epub 2011 Aug 24.
PubMed 21907813
Study at a glance
From the registry record, last updated by the sponsor on 26 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Presence of Neuropathic Pain in Knee Osteoarthritis: Relationship Between Pain Severity and Functional Status
- ClinicalTrials.gov ID
- NCT07367126
- Acronym / sponsor ID
- İstPRMTRH-EK6
- Conditions
- Knee Osteoarthristis
- Keywords
- Pain Intensity, Functional Status, Neuropathic Pain, Knee Osteoarthritis
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 102 participants (estimated)
- Lead sponsor
- Istanbul Physical Medicine Rehabilitation Training and Research HospitalOther government
- Study start
- 20 Dec 2025 (actual)
- Primary completion
- 31 Mar 2026 (estimated)
- Study completion
- 30 Apr 2026 (estimated)
- First posted
- 26 Jan 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.
Osteoarthritis (OA) is a degenerative joint disease characterized by structural changes such as cartilage loss and osteophyte formation, leading to functional limitations and disability. Pain in knee OA involves a complex pathophysiological structure including both nociceptive and neuropathic mechanisms. Identifying the neuropathic pain component is clinically significant for improving quality of life and functional recovery. This cross-sectional controlled clinical study aims to determine the prevalence of neuropathic pain in patients with knee OA and evaluate its impact on pain severity and functional status. Patients will be categorized based on the Douleur Neuropathique 4 (DN4) questionnaire and assessed using various pain and functional scales.
Detailed description
Osteoarthritis (OA) is a degenerative joint disease characterized by structural alterations, including focal cartilage loss, osteophyte formation, subchondral sclerosis, and synovitis. Given the growing elderly population, the prevalence of OA is rising, frequently leading to significant functional limitations and disability. Pain, the most prominent symptom of OA, serves as a critical measure for monitoring disease activity and treatment efficacy.
Recent evidence suggests that OA-related pain involves a complex pathophysiological structure, incorporating both nociceptive and neuropathic mechanisms. Studies indicate that approximately 19-37% of patients with knee OA exhibit symptoms consistent with neuropathic pain. Identifying this neuropathic component is clinically essential, as it may respond differently to conventional analgesics; thus, recognizing it is vital for optimizing functional recovery and quality of life.
This cross-sectional controlled clinical trial aims to determine the prevalence of neuropathic pain in patients with knee OA and evaluate its impact on pain severity and functional status. Participants diagnosed with knee OA according to the American College of Rheumatology (ACR) criteria will be recruited and categorized into two groups based on a Douleur Neuropathique 4 (DN4) questionnaire score threshold of 4/10.
For all participants, comprehensive demographic and clinical data, including age, body mass index (BMI), educational level, occupation, and marital status, will be recorded. To ensure consistency and minimize measurement error, all anthropometric assessments will be performed by a single researcher. The following standardized assessment tools will be administered to all participants: Visual Analog Scale (VAS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Knee Injury and Osteoarthritis Outcome Score-Physical Function Short Form (KOOS-PS).
Study design
- Observational model
- Case-control
- Time perspective
- Cross-sectional
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Group 1 (Case) | – | Other: Clinical and Functional AssessmentPatients with Knee OA and Neuropathic Pain (DN4 score ≥ 4) |
| Group 2 (Control) | – | Other: Clinical and Functional AssessmentPatients with Knee OA without Neuropathic Pain (DN4 score < 4) |
Who may qualify
- Ages
- 40 to 70 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- The source population for this cross-sectional controlled study is the adult patient population diagnosed with knee osteoarthritis (OA) according to the American College of Rheumatology (ACR) criteria, recruited from the Physical Medicine and Rehabilitation outpatient clinic at Istanbul Physical Therapy and Rehabilitation Training and Research Hospital.
Key inclusion criteria (3 listed)
- Diagnosed with Knee OA according to ACR criteria.
- Knee pain for more than 3 months.
- Voluntary participation.
Key exclusion criteria (10 listed)
- History of surgical intervention in the affected knee.
- History of trauma to the affected knee within the last 6 months.
- History of intra-articular injections (e.g., corticosteroids, hyaluronic acid, PRP) or physical therapy involving the affected knee within the last 6 months.
- Presence of severe psychiatric disorders such as severe depression, anxiety disorder, or psychosis.
- Diagnosis of central nervous system diseases, including Parkinson's disease or multiple sclerosis.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Clinical and Functional AssessmentAll participants will undergo a one-time, cross-sectional clinical assessment. Comprehensive demographic and clinical data, including age, body mass index (BMI), educational level, occupation, and marital status, will be recorded for each participant. Pain intensity will be measured using a 10-cm Visual Analog Scale (VAS). Functional status and symptoms related to knee osteoarthritis will be evaluated using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the Knee Injury and Osteoarthritis Outcome Score-Physical Function Short Form (KOOS-PS). To ensure consistency and minimize measurement error, all anthropometric measurements, specifically weight and height, will be performed by the same researcher. | Other | Group 1 (Case), Group 2 (Control) |
Primary outcome
Visual Analog Scale (VAS)
Time frame: at baseline assessment
Pain intensity was assessed using a 10 cm scale, where one end represents "no pain" and the other represents "most severe pain." Patients were asked to rate their pain on a scale from 0 (no pain) to 10 (most severe pain)
Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)
Time frame: at baseline assessment
Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) consists of subscales evaluating pain (5 items), stiffness (2 items), and physical function (17 items). Using a 5-point Likert scale, scores range from 0 (representing the best status/no pain) to 96 (representing the worst status/extreme pain).
1 secondary outcome
Knee Injury and Osteoarthritis Outcome Score - Physical Function Short Form (KOOS-PS)
Time frame: at baseline assessment
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 26 Jan 2026.
- Results publication: PubMed 22665349Ohtori S, Orita S, Yamashita M, Ishikawa T, Ito T, Shigemura T, Nishiyama H, Konno S, Ohta H, Takaso M, Inoue G, Eguchi Y, Ochiai N, Kishida S, Kuniyoshi K, Aoki Y, Arai G, Miyagi M, Kamoda H, Suzkuki M, Nakamura J, Furuya T, Kubota G, Sakuma Y, Oikawa Y, Suzuki M, Sasho T, Nakagawa K, Toyone T, Takahashi K. Existence of a neuropathic pain component in patients with osteoarthritis of the knee. Yonsei Med J. 2012 Jul 1;53(4):801-5. doi: 10.3349/ymj.2012.53.4.801.
- Results publication: PubMed 23973136Hochman JR, Davis AM, Elkayam J, Gagliese L, Hawker GA. Neuropathic pain symptoms on the modified painDETECT correlate with signs of central sensitization in knee osteoarthritis. Osteoarthritis Cartilage. 2013 Sep;21(9):1236-42. doi: 10.1016/j.joca.2013.06.023.
- Results publication: PubMed 17131133Davis MP. What is new in neuropathic pain? Support Care Cancer. 2007 Apr;15(4):363-72. doi: 10.1007/s00520-006-0156-0. Epub 2006 Nov 28.
- Results publication: PubMed 18003941Treede RD, Jensen TS, Campbell JN, Cruccu G, Dostrovsky JO, Griffin JW, Hansson P, Hughes R, Nurmikko T, Serra J. Neuropathic pain: redefinition and a grading system for clinical and research purposes. Neurology. 2008 Apr 29;70(18):1630-5. doi: 10.1212/01.wnl.0000282763.29778.59. Epub 2007 Nov 14.
- Results publication: PubMed 26267003Perrot S. Osteoarthritis pain. Best Pract Res Clin Rheumatol. 2015 Feb;29(1):90-7. doi: 10.1016/j.berh.2015.04.017. Epub 2015 May 16.
- Results publication: PubMed 21907813Pereira D, Peleteiro B, Araujo J, Branco J, Santos RA, Ramos E. The effect of osteoarthritis definition on prevalence and incidence estimates: a systematic review. Osteoarthritis Cartilage. 2011 Nov;19(11):1270-85. doi: 10.1016/j.joca.2011.08.009. Epub 2011 Aug 24.
- Individual participant dataSharing planned: Yes. De-identified individual participant data (IPD), including all demographic, clinical, and primary/secondary outcome measures will be shared with qualified researchers. The sharing period will commence 6 months after article publication and conclude 1 year thereafter. Data access requests must be accompanied by a methodologically sound proposal and will be granted upon the corresponding author's approval and the execution of a Data Use Agreement (DUA) to strictly ensure confidentiality and adherence to ethical guidelines.
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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.
Eser Kalaoglu, M.D. principal investigator
Istanbul Physical Medicine Rehabilitation Training and Research Hospital
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 Knee Osteoarthristis, run by Istanbul Physical Medicine Rehabilitation Training and Research Hospital at 1 site in Turkey (Türkiye).
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 3 inclusion and 10 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: looking for participants now, as of the sponsor's last update on 26 Jan 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 Turkey (Türkiye). 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?
Contact Eser Kalaoglu, M.D. (+90 (212) 496 50 00 ext. 2126, eserkalaoglu@hotmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Visual Analog Scale (VAS) (time frame: at baseline assessment). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07367126, which also lists 6 linked publications.
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 26 Jan 2026.