The Validity and Reliability of the OMERACT in the Turkish Population

The Validity, Reliability, and Clinical Correlation Study of the OMERACT Knee Osteoarthritis Ultrasound Scoring System in the Turkish Population

Knee osteoarthritis is a chronic disease common in middle-aged and older adults, characterized by functional impairment and reduced quality of life due to pain. While physical examination and radiographic Kellgren-Lawrence grading are frequently used in clinical evaluation, the severity of pain does not always correlate with the degree of structural degeneration. Ultrasonography is gaining prominence in osteoarthritis research due to its advantage of simultaneously evaluating both inflammatory and structural components, such as synovial hypertrophy, effusion, power Doppler signal, and osteophytes. The Outcome Measures in Rheumatology (OMERACT) working group has developed a standardized, multidimensional ultrasound scoring system for knee osteoarthritis, and this method is frequently used in the literature. This method consists of a diagnostic ultrasound examination lasting approximately 8-10 minutes. The examination evaluates the anatomical structures of the knee and also includes soft tissue examinations such as synovial hypertrophy. With this method, a diagnostic ultrasound examination lasting approximately 8-10 minutes is performed. The examination evaluates the anatomical structures of the knee and also includes soft tissue examinations such as synovial hypertrophy. Considering the differences between societies in cultural, genetic, biomechanical, body mass index distribution, and healthcare system practices, direct validity, clinical interpretability, and inter-study comparability are of significant importance. The validity, reliability, and applicability of the OMERACT osteoarthritis ultrasound scoring system have been reported in a study conducted on the Egyptian population. However, there is no data on the validity and reliability of OMERACT ultrasound scoring in the Turkish population. This study is the first prospective validation study aimed at establishing standardization for use in clinical practice in Turkey.

Study Overview

• Status: Recruiting
• Conditions: Knee Osteoarthristis

• Study Type: Observational
• Enrollment (Estimated): 100

Contacts and Locations

• Study Contact: Name: Kadir Songür, Assoc. Prof.; Phone Number: +905054529231; Email: kadir.93@gmail.com

Study Locations

• Turkey (Türkiye)
  • İzmir
    • Izmir, İzmir, Turkey (Türkiye), 35570
      • Recruiting
      • Izmir Democracy University
      • Contact: Kadir Songür; Phone Number: 05054529231; Email: kadir.93@gmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

This study will include patients aged 45 years and older who have been diagnosed with knee osteoarthritis based on clinical and radiological evaluation and who have applied to the Physical Medicine and Rehabilitation Outpatient Clinic at İzmir Democracy University Buca Seyfi Demirsoy Education and Research Hospital.

Description

Inclusion Criteria:

• Adults aged 45 years and older
• Patients diagnosed with knee osteoarthritis clinically or radiographically
• Being in a clinical condition that allows tolerance of ultrasound evaluation of both knees
• Being able to provide written informed consent for participation in the study
• Having sufficient cognitive ability to understand Turkish forms and scales

Exclusion Criteria:

• Diagnosis of inflammatory arthritis (rheumatoid arthritis, psoriatic arthritis, gout, CPPD, etc.)
• Intra-articular injection into the knee joint within the last 6 months (corticosteroid, hyaluronic acid, PRP, etc.)
• Previous major knee surgery (total knee replacement, major ligament reconstruction, etc.)
• Acute pathology that has developed within the last 6 weeks, such as acute trauma/fracture/ligament injury
• Severe deformity or severe movement restriction that technically prevents ultrasound examination
• Active infection/systemic febrile condition
• Neurological disease causing motor or sensory deficit in the lower extremities
• Use of Gabapentinoid/SNRI/SSRI due to fibromyalgia or psychiatric illness
• Severe cognitive impairment or communication problems that would prevent participation in the study
• Pregnancy
• Subjects who have been informed about the study and refuse to participate

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
knee osteoarthritis

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Western Ontario and McMaster Universities (WOMAC) score	The WOMAC Osteoarthritis Index questionnaire, consisting of 5 questions using a Likert scale, is provided in the attached case report form to assess pain, stiffness, and daily living functions. The WOMAC Osteoarthritis Index consists of 24 questions covering three subscales: pain (5 questions), stiffness (2 questions), and function (17 questions). The scoring system consists of the WOMAC pain score, WOMAC stiffness score, WOMAC function score, and WOMAC total score. A Turkish validity and reliability study has been conducted.	Day 1
Outcome Measures in Rheumatology knee osteoarthritis scale	Participants' Outcome Measures in Rheumatology knee ultrasound parameters will be evaluated (The necessary permission to use the OMERACT ultrasound protocol in the study has been obtained from Dr. George Bruyn). Ultrasound evaluations will be performed on patients' bilateral knees by two blinded evaluators (the first investigator with 8 years of experience in musculoskeletal ultrasonography and the second investigator with 1 year of experience) using a Philips HD11XE device and a 4-8 MHz linear probe. Synovitis, synovial hypertrophy, effusion, power Doppler signal, cartilage damage, meniscal pathology, and osteophyte scores in the Outcome Measures in Rheumatology knee osteoarthritis scoring system will be evaluated according to Outcome Measures in Rheumatology definitions. A higher Outcome Measures in Rheumatology knee ultrasound score indicates a worse outcome.	Day 1

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Visual analog scale	Visual analog scale measures pain as it is subjectively perceived. It uses a 0-10 cm scale, the most commonly used tool for quantitatively determining pain intensity, with one end representing no pain and the other end representing the most severe pain possible. '0' indicates no pain, while '10' indicates the most severe pain. The individual is asked to select the numerical value that best represents their condition. This marked value is used as numerical data to determine the level of pain perception. A higher score indicates a higher level of pain.	Day 1
Joint Range of Motion measurement	Knee flexion and extension will be measured bilaterally using universal goniometry to assess patients' joint range of motion, and the angles will be recorded.	Day 1
Kellgren-Lawrence Classification	The Kellgren and Lawrence system is a widely used method that classifies the severity of knee osteoarthritis into five grades.	Day 1

Collaborators and Investigators

• Sponsor: Izmir Democracy University

Study record dates

Study Major Dates

• Study Start (Actual): February 1, 2026
• Primary Completion (Estimated): March 1, 2027
• Study Completion (Estimated): September 1, 2027

Study Registration Dates

• First Submitted: February 9, 2026
• First Submitted That Met QC Criteria: February 14, 2026
• First Posted (Actual): February 18, 2026

Study Record Updates

• Last Update Posted (Actual): March 27, 2026
• Last Update Submitted That Met QC Criteria: March 23, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: knee; ultrasonography; ostheoarthritis
• Other Study ID Numbers: 2025 548

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data (IPD) will not be shared because the data contain potentially identifiable sensitive clinical information, and sharing was not covered in the original informed consent provided to participants. Additionally, institutional and national data protection regulations limit the transfer of raw, de-identified individual-level data outside the research team.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No