The Effect of Lipedema on Knee Osteoarthritis

July 7, 2026 updated by: Kadir Songur, Izmir Democracy University

The Effect of Lipedema on Knee Osteoarthritis: A Cross-Sectional Analysis of Clinical Symptoms and Ultrasonographic Findings

This study will be one of the few to examine the effect of lipedema on knee osteoarthritis in a comparative manner with a control group within the same osteoarthritis context. Although the relationship between obesity and osteoarthritis has been extensively studied in the literature, the effect of specific adipose tissue pathologies, such as lipedema, on osteoarthritis has not been sufficiently investigated. This study aims to demonstrate the independent effect of lipedema on osteoarthritis, evaluate clinical and ultrasonographic parameters together, and contribute to early diagnosis and targeted rehabilitation strategies.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
76

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Turkey (Türkiye)
    • İzmir
      • Izmir, İzmir, Turkey (Türkiye), 35570
        • Recruiting
        • Izmir Democracy University
        • Contact:
      • Izmir, İzmir, Turkey (Türkiye), 35570
        • Not yet recruiting
        • Izmir Democracy University
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

This study will include patients aged 30 and older who presented to the Physical Medicine and Rehabilitation Outpatient Clinic at Buca Seyfi Demirsoy Training and Research Hospital, Izmir Democracy University, between July 15, 2026, and July 15, 2027, and who were diagnosed with knee osteoarthritis based on clinical and radiological evaluations. Previously obtained knee X-rays will be retrospectively reviewed, and patients with osteoarthritis findings on X-rays according to the Kellgren-Lawrence grading system will be included in the study. The diagnosis of lipedema will be made by an experienced physical therapy and rehabilitation specialist based on a combined evaluation of clinical and ultrasonographic findings. The clinical diagnosis will be based on the Wold criteria: bilateral and symmetrical fat distribution in the lower extremities, foot sparing, tenderness and pain on palpation, a history of easy bruising, and fat accumulation resistant to diet and exercise.

Description

Inclusion Criteria:

All participants (Group 1 + Group 2)

  • Women aged 30-65
  • With a clinical and radiological diagnosis of knee osteoarthritis
  • Who agreed to participate in the study

Group 1 (knee osteoarthritis with lipedema):

  • Patients who meet the Wold criteria for a clinical diagnosis of lipedema
  • An increase in subcutaneous fat thickness confirmed by ultrasound

Group 2 (knee osteoarthritis without lipedema):

  • No diagnosis of lipedema
  • Exclusion of lymphedema and venous diseases

Exclusion Criteria:

  • Inflammatory arthritis
  • History of knee surgery
  • Intra-articular injection within the past 6 months
  • Acute trauma
  • Systemic connective tissue disease
  • Severe venous insufficiency or lymphedema
  • History of malignancy
  • Use of gabapentinoids/SNRIs/SSRIs due to fibromyalgia or psychiatric illness
  • Severe cognitive impairment or communication problems that would prevent participation in the study
  • Pregnancy
  • Participants who were informed about the study and refused to participate

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Group 1
Knee osteoarthritis with lipedema
Group 2
Knee osteoarthritis without lipedema

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Ultrasonography-based measurements of femoral cartilage thickness
Time Frame: Day 1
During femoral cartilage thickness measurements, participants will be positioned in the supine position, and the knee will be brought to maximum flexion for evaluation through the suprapatellar window. The probe will be positioned in the transverse plane, and measurements will be taken at the level of the medial and lateral femoral condyles and the intercondylar groove. For standardization, each measurement will be repeated three times, and the average will be recorded. Cartilage thickness will be defined as the distance between the hypoechoic cartilage layer and the subchondral bone surface. Lower values indicate that osteoarthritis has caused more structural damage.
Day 1

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Western Ontario and McMaster Universities (WOMAC) score
Time Frame: Day 1
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
Visual analog scale
Time Frame: Day 1
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
Time Frame: Day 1
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
Time Frame: Day 1
The Kellgren and Lawrence system is a widely used method that classifies the severity of knee osteoarthritis into five grades.
Day 1
Assessment of osteophytes via ultrasonography
Time Frame: Day 1
During osteophyte assessment, participants will be positioned in the supine position with the knee flexed approximately 30 degrees; the probe will be placed along the medial and lateral joint lines in the longitudinal and transverse planes to examine bony projections. Osteophytes will be scored according to the Outcome Measures in Rheumatology knee osteoarthritis scale criteria as small (<2 mm - Grade 1), moderate (2-4 mm - Grade 2), and large (>4 mm - Grade 3).
Day 1
Assessment of synovial hypertrophy via ultrasonography
Time Frame: Day 1
In the ultrasound assessment of synovial hypertrophy, the thickness of hypoechoic tissue in the suprapatellar region that does not shift upon probe compression will be measured, and values exceeding 2 mm will be recorded as synovial hypertrophy.
Day 1
Assessment of synovial effusion via ultrasonography
Time Frame: Day 1
Ultrasonographic assessment of joint effusion will be performed at the suprapatellar recess level; participants will be positioned in the supine position with the knee in near-extension or slight flexion. During the longitudinal plane examination, anechoic fluid collections will be measured, and values of 4 mm or greater will be considered pathological synovial effusions.
Day 1
Assessment of meniscal protrusions via ultrasonography
Time Frame: Day 1
During the ultrasound assessment of meniscus protrusion, the knee will be positioned with approximately 30 degrees of flexion, and the extent to which the meniscus tissue extends beyond the tibial margin will be evaluated in measurements taken in the longitudinal plane along the medial joint line; protrusions exceeding 3 mm will be considered pathological meniscus protrusions.
Day 1
Ultrasonography-based measurements of quadriceps muscle thickness
Time Frame: Day 1
For ultrasonographic measurements of quadriceps muscle thickness, participants will be positioned in the supine position with the knee extended and the muscles fully relaxed; measurements taken in the transverse plane at the midpoint between the anterior superior iliac spine and the superior pole of the patella will assess the thicknesses of the rectus femoris and vastus intermedius muscles together.
Day 1
Ultrasonography-based measurements of quadriceps tendon thickness
Time Frame: Day 1
Ultrasonographic measurements of the quadriceps tendon will be taken in the longitudinal plane immediately proximal to the superior pole of the patella while the knee is flexed to approximately 30 degrees, and the average of the measurements taken 5, 10, and 15 mm proximal to this point will be recorded
Day 1
Ultrasonography-based measurements of patellar tendon thickness
Time Frame: Day 1
Ultrasonographic assessment of the patellar tendon is performed with the knee flexed to 30 degrees, in the longitudinal plane from the apex of the patella distally, and the anteroposterior thickness is measured approximately 5 mm distal to the apex.
Day 1

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Ultrasonography-based measurements of pre-tibial and thigh subcutaneous thickness
Time Frame: Day 1
The diagnosis of lipedema will be supported by ultrasonographic measurements of subcutaneous fat thickness in the thigh and pretibial regions. With the patient in the supine position and the lower extremities relaxed and in a neutral position, the probe is placed in the transverse plane (anterior surface of the tibia), at the midpoint between the tibial tuberosity and the medial malleolus, and on the thigh, at the midpoint along the midline between the iliac crest and the lower edge of the patella, and the total thickness of the skin and subcutaneous tissue will be measured in millimeters by applying minimal pressure. Each measurement will be taken three times, and the average will be calculated. In the literature, diagnostic threshold values have been established as a thickness measurement of >11.7 mm in the pre-tibial region and >17.9 mm in the thigh.
Day 1

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Izmir Democracy University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
July 7, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
July 15, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
August 15, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
May 3, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 3, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
May 8, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
July 9, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 7, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
July 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 2026/26

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

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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