An observational study in Knee Arthritis, Osteoarthritis and Osteo Arthritis of the Knee, sponsored by Izmir City Hospital. Completed at 1 site in Turkey (Türkiye). Open to female participants aged 40 Years to 70 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-10-01.
Sponsored by Izmir City Hospital · Observational
Among 268 studies in Osteoarthritis, Knee with a site in Turkey — 54 open to participants now, 66 under way, 3 of them phase 3. Osteoarthritis, Knee · Turkey.
Among the 268 studies in Osteoarthritis, Knee with a site in Turkey, this one is the 49th largest by enrollment of the 70 observational ones that give a count, is one of 38 that started in 2026, is one of 70 observational ones, and was the 234th registered.
3,292 studies on the registry are indexed under Osteoarthritis, Knee; 623 are open to participants now.
Browse Osteoarthritis, Knee studies →54 of the 268 studies in Osteoarthritis, Knee with a site in Turkey are open now. Recruiting first, the newest first:
Bahçeşehir University · Sites in Turkey
Munzur University · Sites in Turkey
Gaziosmanpasa Research and Education Hospital · Sites in Turkey
Mardin Artuklu University · Sites in Turkey
Izmir Democracy University · Sites in Turkey
A study can be open while its sites in Turkey have not opened yet or have stopped. Only those recruiting at a site in Turkey →
Of the 382 Osteoarthritis, Knee studies recruiting now, 176 (46%) set no upper age limit and 113 (30%) stop at 75 or younger; 19 take children under 18; 39 take healthy volunteers.
This study: 40 Years to 70 Years · female · healthy volunteers too.
The full table on the hub →This tab as a report to print or save as PDF → With an account.
268 studies; the count open now beside each. This study's row is marked.
First in 2006; this study’s year is marked. 38 started in 2026.
This study's enrollment of 60 is below the median of 100 across 486 observational studies indexed under Osteoarthritis, Knee.
Median enrollment 60 across the 198 interventional studies, 84 across the 70 observational. Of the 180 that completed or were terminated, 3 (2%) have results posted.
This tab as a report to print or save as PDF → With an account.
5 of 268 have an industry lead sponsor. The 10 most frequent:
Izmir City Hospital is the lead sponsor of 25 studies on the registry; 12 are open to participants now.
Izmir City Hospital has 1 study filed under Osteoarthritis, Knee — fewer than ten, so there is no comparison to draw.
27 of the studies in Osteoarthritis, Knee with a site in Turkey that are under way reach primary completion within a year, 0 of them phase 3. Phase 3 first, then by date:
| Study | Primary completion |
|---|---|
| NCT07767812Kutahya Health Sciences UniversityEffects of Motivational Interviewing on Pain Self-Efficacy and Exercise Behavior in Individuals With Knee Osteoarthritis | 2026-11-15 |
| NCT07678996Kayseri City HospitalDose-Response Effect of Intra-Articular Ozone in Knee Osteoarthritis | 2026-11-30 |
| NCT06430918Bozyaka Training and Research HospitalNeuropathic Pain and it's Relation to Sleep Quality in Knee Osteoarthritis | 2026-12-01 |
| NCT07883824Kirsehir Ahi Evran UniversitesiAquatic Exercise in Patients With Knee Osteoarthritis | 2026-12-01 |
| NCT07890155Sisli Hamidiye Etfal Training and Research HospitalEffect of Resistance Exercises on Serum IGF-1 Levels in Knee Osteoarthritis | 2026-12-01 |
Among the 268 studies in Osteoarthritis, Knee with a site in Turkey, from their registry updates:
This tab as a report to print or save as PDF → With an account.
The purpose of this cross-sectional, observational study is to evaluate the relationship between quadriceps muscle quality-specifically muscle echogenicity and thickness change during isometric contraction-and clinical outcomes such as pain, physical function, quality of life, and Patient Global Assessment (PtGA) in female patients with knee osteoarthritis. Participants will undergo a non-invasive ultrasound evaluation of their thigh muscles and complete standard clinical questionnaires to help determine how muscle structural and functional properties impact the daily lives of patients with knee osteoarthritis.
Knee osteoarthritis (OA) is a highly prevalent degenerative joint disease characterized by pain, loss of function, and reduced quality of life. A critical factor related to the clinical course of the disease is quadriceps muscle weakness and deterioration in muscle quality, including intra-muscular fatty infiltration and fibrotic changes.
This single-center, cross-sectional observational study aims to comprehensively assess quadriceps muscle quality using ultrasonography (USG) and investigate its relationship with core clinical outcomes in patients with knee OA. Specifically, the study will measure muscle echogenicity (a surrogate marker of fat infiltration and fibrosis) and the rate of muscle thickness change during maximum voluntary isometric contraction (MVIC), which reflects the dynamic functional response of the muscle.
Female patients aged 40 to 70 years with radiographically confirmed Kellgren-Lawrence grade 2-3 knee OA will be recruited from the physical medicine and rehabilitation clinic. Following informed consent, participants will undergo clinical assessments using standardized patient-reported outcome measures. These include the Visual Analog Scale (VAS) for pain intensity, the Patient Global Assessment (PtGA), and the Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales for physical function (KOOS-PS) and quality of life (KOOS-QoL).
Ultrasonographic evaluations will be performed by a single evaluator using a linear high-resolution probe (5-10 MHz). Rectus femoris (RF) and vastus intermedius (VI) muscle thicknesses will be recorded at rest and during a 5-second MVIC to calculate the thickness change ratio. Furthermore, muscle echogenicity (mean gray value) will be quantified via image analysis software and mathematically corrected for subcutaneous fat thickness to ensure accuracy.
By evaluating both the structural and functional ultrasonographic features of the quadriceps muscle simultaneously, this study seeks to provide a holistic understanding of how muscle quality impacts the core outcome domains recommended by OMERACT-OARSI for knee osteoarthritis, ultimately contributing to better prognostication and more individualized rehabilitation strategies.
3,292 studies on the registry are indexed under Osteoarthritis, Knee; 623 are open to participants now.
This study's enrollment of 60 is below the median of 100 across 486 observational studies indexed under Osteoarthritis, Knee.
Browse Osteoarthritis, Knee studies →Izmir City Hospital is the lead sponsor of 25 studies on the registry; 12 are open to participants now.
Compared within Osteoarthritis, Knee, this study's primary condition as ClinicalTrials.gg classifies it; the registry's first condition term is Osteoarthritis. The counts are of registry records indexed under each term, refreshed daily. How we classify →
Female patients aged 40-70 years diagnosed with knee osteoarthritis (OA) who apply to the Physical Medicine and Rehabilitation Clinic of Izmir City Hospital will be screened according to the study criteria. Individuals diagnosed clinically and radiographically with Kellgren-Lawrence Grade 2-3 knee osteoarthritis, who are capable of performing isometric quadriceps contractions, and who volunteer to participate in the study will be included after signing the informed consent form.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
This group consists of female patients aged 40-70 years diagnosed with primary knee osteoarthritis (Kellgren-Lawrence Grade 2 and 3) according to the American College of Rheumatology (ACR) criteria. All participants in this cohort will undergo: 1. Ultrasonographic Assessment: Measurement of Rectus Femoris and Vastus Intermedius muscle thickness at rest and during maximum voluntary isometric contraction, along with muscle echogenicity analysis. 2. Clinical Evaluation: Assessment of pain intensity via Visual Analog Scale (VAS), and evaluation of functional status and quality of life using the Knee Injury and Osteoarthritis Outcome Score (KOOS) and Patient Global Assessment (PtGA).
This group consists of healthy female volunteers aged 40-70 years with no clinical or radiographic evidence of knee osteoarthritis and no history of chronic knee pain. Participants in this control group will undergo the same standardized evaluation protocol as the patient group to provide baseline values for: 1. Ultrasonographic Assessment: Measurement of Rectus Femoris and Vastus Intermedius muscle thickness at rest and during maximum voluntary isometric contraction, along with muscle echogenicity analysis. 2. Clinical Evaluation: Assessment of pain intensity via Visual Analog Scale (VAS), and evaluation of functional status and quality of life using the Knee Injury and Osteoarthritis Outcome Score (KOOS) and Patient Global Assessment (PtGA).
Knee Injury and Osteoarthritis Outcome Score - Physical Function Short Form (KOOS-PS)
The primary outcome is physical function, reflecting the capacity to perform activities of daily living. KOOS-PS is a 7-item patient-reported measure assessing functional difficulties (e.g., getting in/out of bed, putting on socks, squatting). Scores for each item range from 0 to 4, and the total score is transformed to a 0-100 scale. A lower score indicates better physical function.
Time frame: Baseline
Pain Intensity via Visual Analog Scale (VAS)
Participants' pain levels will be assessed using the Visual Analogue Scale (VAS). The VAS is a validated tool designed to convert subjective sensations, such as pain, into quantitative data. During the assessment, a 10-cm horizontal line will be utilized, with the endpoints defined as '0: No pain' and '10: Most severe pain imaginable.' Patients will be instructed to mark the point on this line that best represents their current pain intensity.
Time frame: Baseline
Knee Injury and Osteoarthritis Outcome Score - Quality of Life (KOOS-QoL)
This 4-item subscale evaluates the impact of knee problems on the patient's quality of life, including awareness of knee problems, lifestyle modifications to protect the knee, lack of confidence in the knee, and general knee-related difficulties. Each item is scored on a Likert scale from 0 to 4. The raw scores are transformed to a 0-100 scale, where 100 represents no symptoms/best possible quality of life and 0 represents extreme symptoms/worst possible quality of life.
Time frame: Baseline
Patient Global Assessment (PtGA)
The Patient Global Assessment (PtGA) is a patient-reported outcome measure reflecting the individual's subjective perception of their overall knee joint status. It integrates the general impact of knee osteoarthritis on the patient's life, including symptom severity and functional burden, into a single indicator. In this study, PtGA will be measured using a 0-10 cm Visual Analog Scale (VAS) based on the standard question: "How would you rate your knee condition in general over the past 7 days?". The scale ranges from 0 (very well) to 10 (very poor). The VAS provides a one-dimensional, practical, and validated method to quantify the patient's global health status related to the knee joint.
Time frame: Baseline
Plan to share: Undecided — No final decision has yet been made regarding the future availability of the data.
Ran from Apr 2026 to primary completion in Sep 2026, 5 months.
Since we started tracking on Sep 25, 2026, the dates moved once, on Oct 1, 2026: primary completion Dec 2026 → Sep 2026 and completion Dec 2026 → Sep 2026.
Earlier changes are on the record history on ClinicalTrials.gov ↗
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is completed, as verified in Sep 2026. You cannot join it, but the record below documents what was studied.
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Izmir City Hospital