Arthroscopic Infrapatellar Fat Pad Release and Mesenchymal Stem Cell Mobilization

NCT07736716 | Completed

• 1 other identifier: E1-21-1670
• Study Type: interventional
• Target: 26
• Locations: 1 country
• Sites: 1

Brief Summary

This prospective, single-center, paired-sample clinical laboratory study evaluated whether controlled mechanical release of the infrapatellar fat pad during knee arthroscopy increases the number of intra-articular cells with a mesenchymal stem cell immunophenotype. The study also evaluated whether the procedure is accompanied by immediate changes in the expression of selected genes associated with inflammation, immunomodulation, and tissue repair. Adults undergoing knee arthroscopy for meniscal pathology had a 20-mL intra-articular fluid sample collected before manipulation of any intra-articular structure. The infrapatellar fat pad was then gently and selectively shaved for approximately 1 minute using a motorized arthroscopic shaver with the suction turned off. A second 20-mL intra-articular fluid sample was collected immediately after the procedure and before further irrigation or continuation of the planned arthroscopic surgery. Paired pre-release and post-release samples were analyzed by flowcytometry to quantify cells with a mesenchymal stem cell immunophenotype. Quantitative real-time polymerase chain reaction was performed on the total cellular fraction to assess IL-1β, IL-6, IL-10, TGF-β, and CD24 gene expression. Comparisons were performed within each participant using the paired samples.

Conditions

Knee Arthroscopy Surgery; Meniscal Tears; Knee Acute and Chronic Pain

Keywords

infrapatellar fatpad; mesenchymal stem cells; knee arthroscopy; mechanical release; flowcytometry; gene expression

Outcome Measures

Primary Outcomes (1)

• Number of Cells With a Mesenchymal Stem Cell Immunophenotype Before and After Infrapatellar Fat Pad Release

  The number of LIN-negative, CD29-positive, CD73-positive, CD13-positive, CD105-positive, CD90-positive, and CD31-negative cells was quantified by flow cytometry in standardized paired intra-articular fluid samples collected before and immediately after controlled mechanical release of the infrapatellar fat pad. Paired cell counts were summarized as median with minimum and maximum values and compared within participants.

  Immediately before and immediately after the approximately 1-minute infrapatellar fat pad release procedure during the same knee arthroscopy

Secondary Outcomes (5)

• Fold Change in IL-1β Gene Expression After Infrapatellar Fat Pad Release

  Immediately before and immediately after the approximately 1-minute infrapatellar fat pad release procedure during the same knee arthroscopy

• Fold Change in IL-6 Gene Expression After Infrapatellar Fat Pad Release

  Immediately before and immediately after the approximately 1-minute infrapatellar fat pad release procedure during the same knee arthroscopy

• Fold Change in IL-10 Gene Expression After Infrapatellar Fat Pad Release

  Immediately before and immediately after the approximately 1-minute infrapatellar fat pad release procedure during the same knee arthroscopy

• Fold Change in TGF-β Gene Expression After Infrapatellar Fat Pad Release

  Immediately before and immediately after the approximately 1-minute infrapatellar fat pad release procedure during the same knee arthroscopy

• Fold Change in CD24 Gene Expression After Infrapatellar Fat Pad Release

  Immediately before and immediately after the approximately 1-minute infrapatellar fat pad release procedure during the same knee arthroscopy

Study Arms (1)

Arthroscopic Infrapatellar Fat Pad Release

EXPERIMENTAL

Participants undergoing routine knee arthroscopy for meniscal pathology underwent paired intra-articular fluid sampling. A 20-mL baseline sample was collected before any intra-articular manipulation. The infrapatellar fat pad was then gently and selectively shaved for approximately 1 minute using a motorized arthroscopic shaver with the suction temporarily turned off. A second 20-mL intra-articular fluid sample was collected immediately after shaving and before further irrigation. The released tissue was subsequently removed using routine arthroscopic suction and irrigation, and the planned arthroscopic procedure was completed.

Procedure: Controlled Mechanical Release of the Infrapatellar Fat Pad

Interventions

Controlled Mechanical Release of the Infrapatellar Fat Pad PROCEDURE

After baseline intra-articular fluid sampling, the infrapatellar fat pad was gently and selectively shaved for approximately 1 minute with the motorized arthroscopic shaver suction temporarily turned off. A second intra-articular fluid sample was collected immediately after shaving and before further irrigation. The released tissue was subsequently removed using routine arthroscopic suction and irrigation. No released tissue or cells were intentionally retained in the joint for therapeutic purposes.

Arthroscopic Infrapatellar Fat Pad Release

Eligibility Criteria

• Age: 18 Years - 55 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• Age between 18 and 55 years
• Presence of knee pain
• Meniscal tear confirmed by magnetic resonance imaging
• Scheduled to undergo arthroscopic knee surgery
• Provision of written informed consent to participate in the study

You may not qualify if:

• Requirement for emergency surgery
• Open injury involving the knee
• Severe anterior or posterior cruciate ligament injury causing substantial knee instability
• Tibial eminence fracture
• Osteochondral defect requiring surgical treatment
• Planned open knee surgery
• Suspected septic arthritis
• Inflammatory arthritis
• Suspected intra-articular tumor
• Previous arthroscopic surgery on the same knee
• Declining to participate in the study

Sponsors & Collaborators

• Ankara City Hospital Bilkent: lead

Study Sites (1)

Ankara Bilkent City Hospital

Ankara, Ankara, 06800, Turkey (Türkiye)

Location

MeSH Terms

Conditions

Chronic Pain

Condition Hierarchy (Ancestors)

Pain; Neurologic Manifestations; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• ibrahim a yavuz, MD, PhD

  Ankara Bilkent City Hospital, Department of Orthopedics and Traumatology

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor of Orthopaedics and Traumatology

Study Record Dates

• First Submitted: July 27, 2026
• First Posted: July 30, 2026
• Study Start: January 9, 2024
• Primary Completion: January 10, 2025
• Study Completion: January 10, 2025
• Last Updated: July 30, 2026

Record last verified: 2026-07

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)