Baker CystNCT07385560

"The Importance of Adding Fenestration to Ultrasound-Guided Baker's Cyst Aspiration"

A study testing Baker's Cyst Aspiration, Steroid-Lidocaine Injection and Ultrasound-Guided Fenestration in people with Baker Cyst and Fenestration, run by Istanbul University - Cerrahpasa at 1 site in Turkey (Türkiye).

Not yet recruiting

Opening soon. The study is approved but enrolment has not started yet. Sites may already take enquiries.

Sites and contacts

Official record

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Trial summary

Who is it for?: Ages 40 to 75 years
Conditions the study is for: Baker Cyst, Fenestration, Musculoskeletal Ultrasound
What is being tested?: Baker's Cyst Aspiration, Steroid-Lidocaine Injection and Ultrasound-Guided Fenestration
Type of treatment: Injection or infusion, Surgery or procedure
Could I receive a placebo?: No, everyone receives an active treatment
How many people: 44 participants
Where: 1 siteTurkey (Türkiye)
Study dates: 15 Feb 2026to 30 May 2026
Phase: Interventional
Are there results?: Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

Ages 40 to 75 years
All sexes
No healthy volunteers
Adult, Older adult

Who may be able to join

Adults aged 40 to 75 years
Diagnosis of knee osteoarthritis according to the 2010 American College of Rheumatology (ACR) criteria
Presence of a symptomatic Baker's cyst confirmed by ultrasonography
Ability to understand study procedures and provide written informed consent
Sufficient intellectual and social capacity to comply with study visits and follow-up requirements

Who cannot join

Presence of inflammatory arthritis, septic arthritis, crystal arthropathy, or secondary causes of knee osteoarthritis
Kellgren-Lawrence grade 4 knee osteoarthritis
Active systemic infection
History of malignancy
Intra-articular knee injection within the past 3 months
Knee trauma within the past 3 months

Show all 12Show fewer

History of knee surgery
Contraindications to aspiration or corticosteroid injection (e.g., local infection, bleeding disorders, uncontrolled diabetes mellitus)
Requirement to continue medications for inflammatory arthritis
Diagnosed psychiatric disorder that may impair study participation
Use of nonsteroidal anti-inflammatory drugs (NSAIDs) within the past 1 week
Physical therapy applied to the knee region within the past 1 month

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

TUTKU NAZ BULUT, MD contact

+90 536 9907083

tutku.bulut@iuc.edu.tr

Turkey (Türkiye)1 site

Istanbul University-Cerrahpasa, Cerrahpasa Faculty of Medicine, Department of Physical Medicine and Rehabilitation
Istanbul, Istanbul, 34098
Tutku Naz bulut, MD, +90 536 990 7083, tutku.bulut@iuc.edu.tr
TUTKU NAZ BULUT, MD

Other trials in Turkey (Türkiye)

About this study

This study aims to evaluate whether adding a fenestration procedure to standard ultrasound-guided aspiration and corticosteroid-lidocaine injection provides additional clinical benefits for patients with symptomatic Baker's cyst associated with knee osteoarthritis. Baker's cyst is a fluid-filled swelling located behind the knee that may cause pain, stiffness, swelling, and limited mobility. Although aspiration with medication injection is commonly used to relieve symptoms, recurrence of the cyst is frequent.

Fenestration is a minimally invasive technique in which small controlled openings are created in the cyst wall under ultrasound guidance to improve internal drainage and potentially reduce recurrence. In this prospective, randomized, double-blind, controlled study, participants will be assigned to one of two groups:

aspiration with corticosteroid and lidocaine injection, or
aspiration with corticosteroid and lidocaine injection plus fenestration.

Pain, functional scores, cyst measurements, and recurrence will be assessed at follow-up visits at 2 weeks, 1 month, and 3 months. The purpose of this study is to determine whether the addition of fenestration results in better symptom improvement and lower rates of recurrence compared with standard aspiration alone.

Read the detailed description

Baker's cyst, also known as a popliteal cyst, is frequently observed in patients with knee osteoarthritis and is typically associated with intra-articular pathology that increases synovial fluid production. Ultrasound-guided aspiration combined with corticosteroid-lidocaine injection is a widely used minimally invasive treatment; however, recurrence remains a significant limitation of this method.

Fenestration involves creating multiple small perforations in the cyst wall using a needle under real-time ultrasound guidance. This technique is expected to enhance communication between the cyst and surrounding tissues, promote better fluid redistribution, and reduce the likelihood of reaccumulation.

This prospective, randomized, double-blind, controlled clinical trial will enroll adult patients meeting the 2010 ACR criteria for knee osteoarthritis and demonstrating a symptomatic Baker's cyst on ultrasound. Participants will be randomized in a 1:1 ratio into two groups:

Group 1: aspiration + corticosteroid-lidocaine injection

Group 2: aspiration + corticosteroid-lidocaine injection + fenestration

All procedures will be performed by a trained physiatrist using sterile technique and real-time ultrasonography. Outcome measures include VAS pain scores, KOOS, WOMAC, Rauschning-Lindgren classification, ultrasonographic cyst dimensions, and aspirated fluid volume. Assessments will be conducted at baseline and at 2-week, 1-month, and 3-month follow-up visits.

The primary objective is to investigate whether fenestration, when added to aspiration, enhances clinical outcomes and reduces recurrence rates. Secondary objectives include evaluating functional improvements, changes in cyst size, and patient-reported symptoms. The study duration for each participant is 3 months, and the overall study is planned to be completed within 5 months.

Conditions: Baker Cyst, Fenestration, Musculoskeletal Ultrasound, Steroid Injection, OMERACT, Knee Osteoarthritis
Being tested: Baker's Cyst Aspiration, Steroid-Lidocaine Injection, Ultrasound-Guided Fenestration
Keywords: Baker's cyst, Knee osteoarthritis, Ultrasound-guided aspiration, Steroid injection, Lidocaine, Fenestration, OMERACT, WOMAC, Musculoskeletal ultrasound, Cyst recurrence, KOOS
Medical subject headings: Popliteal Cyst, Osteoarthritis, Knee

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

Baker's Cyst AspirationProcedure or surgery
With the patient in the prone position, the ultrasound probe is placed transversely over the gastrocnemius-semimembranosus bursa. Under real-time ultrasound guidance, the needle is advanced while visualizing neurovascular structures to avoid injury. Aspiration of the cyst content is performed in all participants.
Steroid-Lidocaine InjectionDrug
Following aspiration, an injection mixture consisting of 1 mL betamethasone,
1 mL of 2% lidocaine, and 1 mL of 0.9% isotonic sodium chloride is administered into the decompressed cyst cavity under ultrasound guidance.
Ultrasound-Guided FenestrationProcedure or surgery
After aspiration, fenestration of the cyst wall is performed under ultrasound guidance. The cyst wall is punctured at a minimum of six different points using a needle to create communication with surrounding tissues and reduce recurrence. Following fenestration, the same steroid and local anesthetic mixture is administered.

Study groups in NCT07385560
Study group	Role	What they receive
Aspiration + Steroid-Lidocaine	Active comparator	Ultrasound-guided aspiration of Baker's cyst followed by injection of corticosteroid and lidocaine mixture. No fenestration is performed. Receives: Procedure: Baker's Cyst Aspiration; Drug: Steroid-Lidocaine Injection
Arm Title: Aspiration + Steroid-Lidocaine + Fenestration	Experimental	Ultrasound-guided aspiration followed by corticosteroid-lidocaine injection and fenestration using multiple needle perforations under real-time ultrasound guidance. Receives: Procedure: Baker's Cyst Aspiration; Drug: Steroid-Lidocaine Injection; Procedure: Ultrasound-Guided Fenestration

What is being measured

The primary outcome is the main question the study is designed to answer.

Change in Baker's Cyst Volume
Baker's cyst volume measured by ultrasonography using three-dimensional linear measurements (height × width × depth) and calculated in cubic millimeters (mm³). Volume measurements will be compared between the two study groups (Aspiration + Steroid-Lidocaine vs. Aspiration + Steroid-Lidocaine + Fenestration). All measurements will be performed by a blinded physician using a 7-13 MHz linear transducer. Lower values indicate a reduction in cyst size.
Measured: Baseline, 2 weeks, 1 month, and 3 months after the intervention

Secondary outcomes (9)

Change in Pain Severity (NRS Score)
Pain severity will be assessed using the Numeric Rating Scale (NRS; 0-10), where 0 indicates "no pain" and 10 indicates "worst imaginable pain." Pain levels will be recorded at each follow-up visit, and changes over time will be compared between the two study groups.
Measured: Baseline, 1 hour post-procedure, 2 weeks, 1 month, 3 months.
Change in Rauschning-Lindgren Classification (RLC)
Clinical severity of Baker's cyst-related knee symptoms assessed using the Rauschning-Lindgren Classification, a 4-grade clinical scale ranging from Grade 0 to Grade 3. Grade 0 indicates no swelling, pain, limitation of range of motion, instability, or functional restriction. Grade 1 represents mild symptoms such as slight swelling or discomfort after strenuous activity with minimal functional limitation.
Grade 2 corresponds to moderate swelling and pain following moderate exertion, with measurable limitation of knee range of motion and reduced participation in physical activities. Grade 3 reflects severe symptoms, including marked swelling, pain at rest or interfering with activities of daily living, significant limitation of knee motion, instability, and inability to participate in work or sports activities.
Higher grades indicate greater clinical severity of symptoms.
Measured: Baseline, 2 weeks, 1 month, 3 months.
Change in Knee Injury and Osteoarthritis Outcome Score (KOOS)
The Knee Injury and Osteoarthritis Outcome Score (KOOS) consists of five subscales: Pain (9 items), Symptoms (7 items), Activities of Daily Living (17 items), Sport and Recreation Function (5 items), and Knee-related Quality of Life (4 items).Each item is scored on a 5-point Likert scale from 0 to 4. Raw subscale scores are calculated by summing the item scores within each subscale and are subsequently transformed to a 0-100 scale using the standard KOOS transformation formula, where 0 represents extreme knee problems and 100 represents no knee problems.
The KOOS total score is calculated as the arithmetic mean of the five normalized subscale scores. Higher total scores indicate better knee-related symptoms, function, and quality of life.
Measured: Baseline, 2 weeks, 1 month, 3 months.
Change in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)
The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) is a disease-specific, patient-reported outcome measure consisting of 24 items grouped into three subscales: Pain (5 items), Stiffness (2 items), and Physical Function (17 items).
Each item is scored on a 5-point Likert scale ranging from 0 (none) to 4 (extreme). Raw subscale scores are calculated by summing the item scores within each subscale, with maximum possible scores of 20 for Pain, 8 for Stiffness, and 68 for Physical Function, resulting in a total raw score ranging from 0 to 96.
For analysis, raw scores are summed to generate the WOMAC total score. Higher total scores indicate worse pain, stiffness, and physical dysfunction related to knee osteoarthritis.
Measured: Baseline, 2 weeks, 1 month, 3 months.
Baseline OMERACT Ultrasound Score
Baseline knee ultrasound assessment will be performed according to the OMERACT (Outcome Measures in Rheumatology) ultrasound definitions for knee osteoarthritis.
Synovitis will be assessed in the suprapatellar and medial/lateral parapatellar recesses using standardized longitudinal and transverse scanning planes and graded from Grade 0 to Grade 3, where higher grades indicate greater synovial distension by abnormal hypoechoic or anechoic material.
Synovial hypertrophy will be graded from Grade 0 to Grade 1 based on the presence of non-displaceable intra-articular tissue. Joint effusion will be evaluated in the parapatellar recesses and graded as Grade 0 (absent) or Grade 1 (present). Power Doppler signal will be recorded as present or absent.
Baseline structural findings including cartilage damage (Grade 0-3), meniscal extrusion (Grade 0-2), and osteophytes (Grade 0-3) will be documented. Higher grades indicate more severe pathology.
Measured: Baseline
Change in Kellgren-Lawrence (K-L) Grade
Radiographic severity of knee osteoarthritis will be assessed using the Kellgren-Lawrence (K-L) classification based on standard anteroposterior knee radiographs. The K-L grading system ranges from Grade 0 to Grade 4, where Grade 0 indicates no radiographic features of osteoarthritis; Grade 1 indicates doubtful joint space narrowing with possible osteophyte formation; Grade 2 indicates definite osteophytes with possible joint space narrowing; Grade 3 indicates multiple osteophytes, definite joint space narrowing, sclerosis, and possible bony deformity; and Grade 4 indicates large osteophytes, marked joint space narrowing, severe sclerosis, and definite bony deformity.
Higher grades indicate more severe radiographic osteoarthritis. Baseline K-L grade will be used for descriptive and subgroup analyses, as structural radiographic change is not expected during short-term follow-up.
Measured: Baseline only
Change in Cyst Characteristics on Ultrasound
Baker's cyst morphology will be classified as simple or complex based on ultrasound appearance. A simple cyst is defined as an anechoic, unilocular structure without internal septations or echogenic material, whereas a complex cyst is defined by the presence of internal septations, echogenic contents, wall thickening, or irregular morphology.
Changes in cyst complexity over time will be compared between the two study groups.
Measured: Baseline, 2 weeks, 1 month, 3 months.
Aspirated Fluid Volume
Total volume of aspirated Baker's cyst fluid measured in milliliters (mL) during the procedure. Higher volumes indicate greater cyst content.
Measured: During the procedure (single time point).
Change in Ultrasound Effusion Grade (OMERACT)
Joint effusion assessed by ultrasonography using the OMERACT semiquantitative grading system for knee osteoarthritis, ranging from Grade 0 to Grade 1. Grade 0 indicates no effusion, while Grade 1 indicates the presence of abnormal hypoechoic or anechoic intra-articular fluid that is displaceable and compressible and does not exhibit Power Doppler signal.
Changes in effusion grade over time will be compared between the two study groups. Higher grades indicate greater joint effusion.
Measured: Baseline, 2 weeks, 1 month, and 3 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

15 Feb 202630 May 2026

First posted4 Feb 2026
Study start15 Feb 2026 (estimated)
Primary completion30 May 2026 (estimated)
Study completion30 May 2026 (estimated)

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Publications (10)Papers the sponsor has linked to this study.
Other trials for Baker CystStudies of the same condition, open and under way.
More trials run by Istanbul University - CerrahpasaThe sponsor's other registered studies.
What the trial phases meanHow a treatment moves from first tests in people to approval.

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design

Study type: Interventional
Phase: Phase N/A
Primary purpose: Treatment
Allocation: Randomised
Intervention model: Parallel groups
Model description: "Two-arm, parallel-group, randomized controlled interventional study evaluating the clinical effects of adding fenestration to ultrasound-guided aspiration."
Masking: Triple blind
Who is masked: Participant, Investigator, Outcomes assessor
Enrolment: 44 participants (estimated)

IDs, dates and publications

ClinicalTrials.gov ID: NCT07385560
Sponsor's protocol ID: E-24687290-604.01-1407310
Other IDs: E-24687290-604.01-1407310
Status last verified: Jan 2026
First submitted: 22 Jan 2026
Last updated: 4 Feb 2026
Results posted: No
FDA-regulated drug: No
FDA-regulated device: No
Individual data sharing: No: Individual participant-level data will not be shared. Study results will be reported in aggregated form in a manner that does not allow identification of individual participants.

Publications

Kim JM, Kang S, Yoon JS. Association of complicated Baker's cysts with knee pathologies as compared to simple Baker's cysts. Medicine (Baltimore). 2024 Jun 7;103(23):e38407. doi: 10.1097/MD.0000000000038407.
PubMed 38847688
Mortada M, Amer YA, Zaghlol RS. Efficacy and Safety of Musculoskeletal Ultrasound Guided Aspiration and Intra-Lesional Corticosteroids Injection of Ruptured Baker's Cyst: A Retrospective Observational Study. Clin Med Insights Arthritis Musculoskelet Disord. 2020 Nov 10;13:1179544120967383. doi: 10.1177/1179544120967383. eCollection 2020.
PubMed 33223862
Collins NJ, Misra D, Felson DT, Crossley KM, Roos EM. Measures of knee function: International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form, Knee Injury and Osteoarthritis Outcome Score (KOOS), Knee Injury and Osteoarthritis Outcome Score Physical Function Short Form (KOOS-PS), Knee Outcome Survey Activities of Daily Living Scale (KOS-ADL), Lysholm Knee Scoring Scale, Oxford Knee Score (OKS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Activity Rating Scale (ARS), and Tegner Activity Score (TAS). Arthritis Care Res (Hoboken). 2011 Nov;63 Suppl 11(0 11):S208-28. doi: 10.1002/acr.20632. No abstract available.
PubMed 22588746
Ferdousi A, Islam MA, Begum M, Debnath MR, Shapla SP, Saha T, Biswas R, Ferdouse F, Rahman MA. Diagnostic Value of Ultrasonography in Determination of Knee Joint Pathologies with Comparison to MRI. Mymensingh Med J. 2024 Oct;33(4):989-995.
PubMed 39351715
Bandinelli F, Fedi R, Generini S, Porta F, Candelieri A, Mannoni A, Innocenti M, Matucci Cerinic M. Longitudinal ultrasound and clinical follow-up of Baker's cysts injection with steroids in knee osteoarthritis. Clin Rheumatol. 2012 Apr;31(4):727-31. doi: 10.1007/s10067-011-1909-9. Epub 2011 Dec 27.
PubMed 22200813
Chen CK, Lew HL, Liao RI. Ultrasound-guided diagnosis and aspiration of Baker's cyst. Am J Phys Med Rehabil. 2012 Nov;91(11):1002-4. doi: 10.1097/PHM.0b013e318269d95b. No abstract available.
PubMed 22955026
Oo WM, Linklater JM, Bennell KL, Pryke D, Yu S, Fu K, Wang X, Duong V, Hunter DJ. Are OMERACT Knee Osteoarthritis Ultrasound Scores Associated With Pain Severity, Other Symptoms, and Radiographic and Magnetic Resonance Imaging Findings? J Rheumatol. 2021 Feb;48(2):270-278. doi: 10.3899/jrheum.191291. Epub 2020 May 15.
PubMed 32414954
Acebes JC, Sanchez-Pernaute O, Diaz-Oca A, Herrero-Beaumont G. Ultrasonographic assessment of Baker's cysts after intra-articular corticosteroid injection in knee osteoarthritis. J Clin Ultrasound. 2006 Mar-Apr;34(3):113-7. doi: 10.1002/jcu.20210.
PubMed 16547992
Smith MK, Lesniak B, Baraga MG, Kaplan L, Jose J. Treatment of Popliteal (Baker) Cysts With Ultrasound-Guided Aspiration, Fenestration, and Injection: Long-term Follow-up. Sports Health. 2015 Sep-Oct;7(5):409-14. doi: 10.1177/1941738115585520. Epub 2015 May 5.
PubMed 26502415
Abate M, Di Carlo L, Di Iorio A, Salini V. Baker's Cyst with Knee Osteoarthritis: Clinical and Therapeutic Implications. Med Princ Pract. 2021;30(6):585-591. doi: 10.1159/000518792. Epub 2021 Aug 2.
PubMed 34348320

Study at a glance

From the registry record, last updated by the sponsor on 4 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: "The Importance of Adding Fenestration to Ultrasound-Guided Baker's Cyst Aspiration"
ClinicalTrials.gov ID: NCT07385560
Acronym / sponsor ID: E-24687290-604.01-1407310
Conditions: Baker Cyst, Fenestration, Musculoskeletal Ultrasound, Steroid Injection, OMERACT, Knee Osteoarthritis
Keywords: Baker's cyst, Knee osteoarthritis, Ultrasound-guided aspiration, Steroid injection, Lidocaine, Fenestration, OMERACT, WOMAC
Study type: Interventional
Recruitment status: Not yet recruiting
Enrolment: 44 participants (estimated)
Lead sponsor: Istanbul University - CerrahpasaUniversity, hospital or other
Study start: 15 Feb 2026 (estimated)
Primary completion: 30 May 2026 (estimated)
Study completion: 30 May 2026 (estimated)
First posted: 4 Feb 2026 (actual)
Results: Not posted in the source record

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

aspiration with corticosteroid and lidocaine injection, or
aspiration with corticosteroid and lidocaine injection plus fenestration.

Detailed description

Group 1: aspiration + corticosteroid-lidocaine injection

Group 2: aspiration + corticosteroid-lidocaine injection + fenestration

Study design

Primary purpose: Treatment
Allocation: Randomised
Intervention model: Parallel groups
Masking: Triple blind (participant, investigator, outcomes assessor)
Number of arms: 2
Model description: "Two-arm, parallel-group, randomized controlled interventional study evaluating the clinical effects of adding fenestration to ultrasound-guided aspiration."

Arm	Type	Receives
Aspiration + Steroid-Lidocaine	Active comparator	Procedure: Baker's Cyst Aspiration, Drug: Steroid-Lidocaine InjectionUltrasound-guided aspiration of Baker's cyst followed by injection of corticosteroid and lidocaine mixture. No fenestration is performed.
Arm Title: Aspiration + Steroid-Lidocaine + Fenestration	Experimental	Procedure: Baker's Cyst Aspiration, Drug: Steroid-Lidocaine Injection, Procedure: Ultrasound-Guided FenestrationUltrasound-guided aspiration followed by corticosteroid-lidocaine injection and fenestration using multiple needle perforations under real-time ultrasound guidance.

Who may qualify

Ages: 40 to 75 years
Sex: All
Healthy volunteers: Not accepted
Age groups: Adult, Older adult

Key inclusion criteria (5 listed)

Adults aged 40 to 75 years
Diagnosis of knee osteoarthritis according to the 2010 American College of Rheumatology (ACR) criteria
Presence of a symptomatic Baker's cyst confirmed by ultrasonography
Ability to understand study procedures and provide written informed consent
Sufficient intellectual and social capacity to comply with study visits and follow-up requirements

Key exclusion criteria (12 listed)

Presence of inflammatory arthritis, septic arthritis, crystal arthropathy, or secondary causes of knee osteoarthritis
Kellgren-Lawrence grade 4 knee osteoarthritis
Active systemic infection
History of malignancy
Intra-articular knee injection within the past 3 months

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Interventions

Intervention	Type	Arms
Baker's Cyst AspirationWith the patient in the prone position, the ultrasound probe is placed transversely over the gastrocnemius-semimembranosus bursa. Under real-time ultrasound guidance, the needle is advanced while visualizing neurovascular structures to avoid injury. Aspiration of the cyst content is performed in all participants.	Procedure or surgery	Arm Title: Aspiration + Steroid-Lidocaine + Fenestration, Aspiration + Steroid-Lidocaine
Steroid-Lidocaine InjectionFollowing aspiration, an injection mixture consisting of 1 mL betamethasone, 1 mL of 2% lidocaine, and 1 mL of 0.9% isotonic sodium chloride is administered into the decompressed cyst cavity under ultrasound guidance.	Drug	Arm Title: Aspiration + Steroid-Lidocaine + Fenestration, Aspiration + Steroid-Lidocaine
Ultrasound-Guided FenestrationAfter aspiration, fenestration of the cyst wall is performed under ultrasound guidance. The cyst wall is punctured at a minimum of six different points using a needle to create communication with surrounding tissues and reduce recurrence. Following fenestration, the same steroid and local anesthetic mixture is administered.	Procedure or surgery	Arm Title: Aspiration + Steroid-Lidocaine + Fenestration

Primary outcome

Change in Baker's Cyst Volume
Time frame: Baseline, 2 weeks, 1 month, and 3 months after the intervention
Baker's cyst volume measured by ultrasonography using three-dimensional linear measurements (height × width × depth) and calculated in cubic millimeters (mm³). Volume measurements will be compared between the two study groups (Aspiration + Steroid-Lidocaine vs. Aspiration + Steroid-Lidocaine + Fenestration). All measurements will be performed by a blinded physician using a 7-13 MHz linear transducer. Lower values indicate a reduction in cyst size.

9 secondary outcomes

Change in Pain Severity (NRS Score)
Time frame: Baseline, 1 hour post-procedure, 2 weeks, 1 month, 3 months.
Change in Rauschning-Lindgren Classification (RLC)
Time frame: Baseline, 2 weeks, 1 month, 3 months.
Change in Knee Injury and Osteoarthritis Outcome Score (KOOS)
Time frame: Baseline, 2 weeks, 1 month, 3 months.
Change in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)
Time frame: Baseline, 2 weeks, 1 month, 3 months.
Baseline OMERACT Ultrasound Score
Time frame: Baseline
Change in Kellgren-Lawrence (K-L) Grade
Time frame: Baseline only
Change in Cyst Characteristics on Ultrasound
Time frame: Baseline, 2 weeks, 1 month, 3 months.
Aspirated Fluid Volume
Time frame: During the procedure (single time point).
Change in Ultrasound Effusion Grade (OMERACT)
Time frame: Baseline, 2 weeks, 1 month, and 3 months

Results and safety

This study is still under way. Results are not available in the source record yet.

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 4 Feb 2026.
Background: PubMed 38847688Kim JM, Kang S, Yoon JS. Association of complicated Baker's cysts with knee pathologies as compared to simple Baker's cysts. Medicine (Baltimore). 2024 Jun 7;103(23):e38407. doi: 10.1097/MD.0000000000038407.
Background: PubMed 33223862Mortada M, Amer YA, Zaghlol RS. Efficacy and Safety of Musculoskeletal Ultrasound Guided Aspiration and Intra-Lesional Corticosteroids Injection of Ruptured Baker's Cyst: A Retrospective Observational Study. Clin Med Insights Arthritis Musculoskelet Disord. 2020 Nov 10;13:1179544120967383. doi: 10.1177/1179544120967383. eCollection 2020.
Background: PubMed 22588746Collins NJ, Misra D, Felson DT, Crossley KM, Roos EM. Measures of knee function: International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form, Knee Injury and Osteoarthritis Outcome Score (KOOS), Knee Injury and Osteoarthritis Outcome Score Physical Function Short Form (KOOS-PS), Knee Outcome Survey Activities of Daily Living Scale (KOS-ADL), Lysholm Knee Scoring Scale, Oxford Knee Score (OKS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Activity Rating Scale (ARS), and Tegner Activity Score (TAS). Arthritis Care Res (Hoboken). 2011 Nov;63 Suppl 11(0 11):S208-28. doi: 10.1002/acr.20632. No abstract available.
Background: PubMed 39351715Ferdousi A, Islam MA, Begum M, Debnath MR, Shapla SP, Saha T, Biswas R, Ferdouse F, Rahman MA. Diagnostic Value of Ultrasonography in Determination of Knee Joint Pathologies with Comparison to MRI. Mymensingh Med J. 2024 Oct;33(4):989-995.
Background: PubMed 22200813Bandinelli F, Fedi R, Generini S, Porta F, Candelieri A, Mannoni A, Innocenti M, Matucci Cerinic M. Longitudinal ultrasound and clinical follow-up of Baker's cysts injection with steroids in knee osteoarthritis. Clin Rheumatol. 2012 Apr;31(4):727-31. doi: 10.1007/s10067-011-1909-9. Epub 2011 Dec 27.
Background: PubMed 22955026Chen CK, Lew HL, Liao RI. Ultrasound-guided diagnosis and aspiration of Baker's cyst. Am J Phys Med Rehabil. 2012 Nov;91(11):1002-4. doi: 10.1097/PHM.0b013e318269d95b. No abstract available.
Background: PubMed 32414954Oo WM, Linklater JM, Bennell KL, Pryke D, Yu S, Fu K, Wang X, Duong V, Hunter DJ. Are OMERACT Knee Osteoarthritis Ultrasound Scores Associated With Pain Severity, Other Symptoms, and Radiographic and Magnetic Resonance Imaging Findings? J Rheumatol. 2021 Feb;48(2):270-278. doi: 10.3899/jrheum.191291. Epub 2020 May 15.
Background: PubMed 16547992Acebes JC, Sanchez-Pernaute O, Diaz-Oca A, Herrero-Beaumont G. Ultrasonographic assessment of Baker's cysts after intra-articular corticosteroid injection in knee osteoarthritis. J Clin Ultrasound. 2006 Mar-Apr;34(3):113-7. doi: 10.1002/jcu.20210.
Background: PubMed 26502415Smith MK, Lesniak B, Baraga MG, Kaplan L, Jose J. Treatment of Popliteal (Baker) Cysts With Ultrasound-Guided Aspiration, Fenestration, and Injection: Long-term Follow-up. Sports Health. 2015 Sep-Oct;7(5):409-14. doi: 10.1177/1941738115585520. Epub 2015 May 5.
Background: PubMed 34348320Abate M, Di Carlo L, Di Iorio A, Salini V. Baker's Cyst with Knee Osteoarthritis: Clinical and Therapeutic Implications. Med Princ Pract. 2021;30(6):585-591. doi: 10.1159/000518792. Epub 2021 Aug 2.
Individual participant dataSharing planned: No. Individual participant-level data will not be shared. Study results will be reported in aggregated form in a manner that does not allow identification of individual participants.

Referral and contact

AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.

TUTKU NAZ BULUT, MD contact

+90 536 9907083

tutku.bulut@iuc.edu.tr

TUTKU NAZ BULUT, MD principal investigator

Istanbul University - Cerrahpasa

1 site in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 5 inclusion and 12 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: opening soon, as of the sponsor's last update on 4 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact TUTKU NAZ BULUT, MD (+90 536 9907083, tutku.bulut@iuc.edu.tr), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Change in Baker's Cyst Volume (time frame: Baseline, 2 weeks, 1 month, and 3 months after the intervention). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07385560, which also lists 10 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 4 Feb 2026.