Quadriceps Muscle Quality and Clinical Outcomes in Knee Osteoarthritis
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- This is an observational study: the protocol does not assign a study treatment.
- Who it may be relevant to
- Registry conditions: Knee Arthritis, Osteoarthritis, Osteo Arthritis of the Knee. Basic parameters: 40 years — 70 years · Female.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Turkey (Türkiye)
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Official title
The Relationship of Quadriceps Muscle Echogenicity and Thickness Change During Isometric Contraction With Pain, Function, Quality of Life, and Patient Global Assessment in Knee Osteoarthritis
Overview
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.
Detailed description
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 (grayscale median) 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.
Primary outcome measures
- Knee Injury and Osteoarthritis Outcome Score - Physical Function Short Form (KOOS-PS) [Time frame: Baseline]
Secondary outcome measures (3)
- Pain Intensity via Visual Analog Scale (VAS) [Time frame: Baseline]
- Knee Injury and Osteoarthritis Outcome Score - Quality of Life (KOOS-QoL) [Time frame: Baseline]
- Patient Global Assessment (PtGA) [Time frame: Baseline]
Eligibility criteria
Inclusion criteria
- Female sex
- Aged between 40 and 70 years
- Diagnosed with clinical and radiographic primary knee osteoarthritis (Kellgren-Lawrence Grade 2 or 3)
- Ability to perform isometric contraction at 90° of knee flexion
- Voluntary participation and provision of written informed consent
Exclusion criteria
- History of knee surgery within the last 6 months
- Intra-articular injection (e.g., corticosteroids, hyaluronic acid) within the last 3 months
- Presence of inflammatory rheumatic diseases (e.g., Rheumatoid Arthritis, Spondyloarthropathy)
- Known neuromuscular disorders affecting the lower extremities
- Severe cardiopulmonary comorbidities that prevent participation in clinical assessments
- Severe patellofemoral instability
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: Yes
Study design
- Observational model
- Case-control
Study locations
Turkey (Türkiye) · 1 center
- Izmir Cıty Hospital — Izmir
Publications
- Young HJ, Jenkins NT, Zhao Q, Mccully KK. Measurement of intramuscular fat by muscle echo intensity. Muscle Nerve. 2015 Dec;52(6):963-71. doi: 10.1002/mus.24656. Epub 2015 Sep 7. PMID 25787260
- Tolk JJ, Janssen RPA, Prinsen CAC, Latijnhouwers DAJM, van der Steen MC, Bierma-Zeinstra SMA, Reijman M. The OARSI core set of performance-based measures for knee osteoarthritis is reliable but not valid and responsive. Knee Surg Sports Traumatol Arthrosc. 2019 Sep;27(9):2898-2909. doi: 10.1007/s00167-017-4789-y. Epub 2017 Nov 11. PMID 29128879
- Carvalho MTX, Pinheiro VHG, Alberton CL. Ultrasonographic assessment of quadriceps muscle in people with knee osteoarthritis: A systematic review and meta-analysis. Ann Phys Rehabil Med. 2025 Oct;68(7):101998. doi: 10.1016/j.rehab.2025.101998. Epub 2025 Jul 8. PMID 40633265
- KELLGREN JH, LAWRENCE JS. Radiological assessment of osteo-arthrosis. Ann Rheum Dis. 1957 Dec;16(4):494-502. doi: 10.1136/ard.16.4.494. No abstract available. PMID 13498604
- Gul ED, Yilmaz O, Bodur H. Reliability and validity of the Turkish version of the knee injury and osteoarthritis outcome score-physical function short-form (KOOS-PS). J Back Musculoskelet Rehabil. 2013;26(4):461-6. doi: 10.3233/BMR-130406. PMID 23948834
Identifiers
NCT: NCT07541274 · HIC26