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

NCT07385560 | Not Yet Recruiting

• 1 other identifier: E-24687290-604.01-1407310
• Study Type: interventional
• Target: 44
• Locations: 1 country
• Sites: 1

Brief Summary

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:

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

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; Musculoskeletal ultrasound; Cyst recurrence; KOOS

Outcome Measures

Primary Outcomes (1)

• 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.

  Baseline, 2 weeks, 1 month, and 3 months after the intervention

Secondary Outcomes (9)

• Change in Pain Severity (NRS Score)

  Baseline, 1 hour post-procedure, 2 weeks, 1 month, 3 months.

• Change in Rauschning-Lindgren Classification (RLC)

  Baseline, 2 weeks, 1 month, 3 months.

• Change in Knee Injury and Osteoarthritis Outcome Score (KOOS)

  Baseline, 2 weeks, 1 month, 3 months.

• Change in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)

  Baseline, 2 weeks, 1 month, 3 months.

• Baseline OMERACT Ultrasound Score

  Baseline

Other Outcomes (1)

• Post-Procedure Pain Change (Short-Term Response)

  Baseline and 1 hour after the procedure.

Study Arms (2)

Aspiration + Steroid-Lidocaine

ACTIVE COMPARATOR

Ultrasound-guided aspiration of Baker's cyst followed by injection of corticosteroid and lidocaine mixture. No fenestration is performed.

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.

Procedure: Baker's Cyst Aspiration; Drug: Steroid-Lidocaine Injection; Procedure: Ultrasound-Guided Fenestration

Interventions

Baker's Cyst Aspiration PROCEDURE

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.

Arm Title: Aspiration + Steroid-Lidocaine + Fenestration; Aspiration + Steroid-Lidocaine

Steroid-Lidocaine Injection DRUG

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.

Arm Title: Aspiration + Steroid-Lidocaine + Fenestration; Aspiration + Steroid-Lidocaine

Ultrasound-Guided Fenestration PROCEDURE

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.

Arm Title: Aspiration + Steroid-Lidocaine + Fenestration

Eligibility Criteria

• Age: 40 Years - 75 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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

You may not qualify if:

• 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
• 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

Sponsors & Collaborators

• Istanbul University - Cerrahpasa: lead

Study Sites (1)

Istanbul University-Cerrahpasa, Cerrahpasa Faculty of Medicine, Department of Physical Medicine and Rehabilitation

Istanbul, Istanbul, 34098, Turkey (Türkiye)

Location

Related Publications (10)

• 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.

  PMID: 38847688 BACKGROUND

• 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.

  PMID: 33223862 BACKGROUND

• 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.

  PMID: 22588746 BACKGROUND

• 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.

  PMID: 39351715 BACKGROUND

• 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.

  PMID: 22200813 BACKGROUND

• 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.

  PMID: 22955026 BACKGROUND

• 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.

  PMID: 32414954 BACKGROUND

• 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.

  PMID: 16547992 BACKGROUND

• 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.

  PMID: 26502415 BACKGROUND

• 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.

  PMID: 34348320 BACKGROUND

MeSH Terms

Conditions

Popliteal Cyst; Osteoarthritis, Knee

Condition Hierarchy (Ancestors)

Synovial Cyst; Cysts; Neoplasms; Osteoarthritis; Arthritis; Joint Diseases; Musculoskeletal Diseases; Rheumatic Diseases

Study Officials

• TUTKU NAZ BULUT, MD

  Istanbul University - Cerrahpasa

  PRINCIPAL INVESTIGATOR

Central Study Contacts

TUTKU NAZ BULUT, MD

CONTACT

+90 536 9907083; tutku.bulut@iuc.edu.tr

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: This is a double-blind study. Participants and investigators who perform evaluations are blinded to group assignment. The clinician performing the ultrasound-guided procedure is not involved in outcome assessments.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Resident Physician, Department of Physical Medicine and Rehabilitation

Model Details: "Two-arm, parallel-group, randomized controlled interventional study evaluating the clinical effects of adding fenestration to ultrasound-guided aspiration."

Study Record Dates

• First Submitted: January 22, 2026
• First Posted: February 4, 2026
• Study Start: February 15, 2026
• Primary Completion (Estimated): May 30, 2026
• Study Completion (Estimated): May 30, 2026
• Last Updated: February 4, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)