Ultrasound-Guided Interfascial Hydrodissection for Gluteal Myofascial Pain in Piriformis Syndrome: A Prospective Study

March 11, 2026 updated by: Busra Nur Aslantas, Istanbul University - Cerrahpasa

Efficacy of Ultrasound-Guided Interfascial Hydrodissection for Myofascial Pain Syndrome of the Gluteus Maximus in Patients With Piriformis Syndrome: A Double-Blind Randomized Controlled Trial.

This randomized, double-blind prospective trial investigates whether ultrasound-guided interfascial hydrodissection using 10% dextrose is more effective than dry needling in treating gluteal myofascial pain coexisting with piriformis syndrome. Following diagnostic piriformis injection response, eligible patients will be randomized into two treatment arms and followed at 1 hour, 1 week, 1 month, and 3 months. The primary hypothesis is that interfascial hydrodissection will provide superior long-term analgesic outcomes due to fascial separation, neuromodulation, and nociceptor suppression.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet 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.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Piriformis syndrome (PS) is a neuromuscular condition characterized by compression or irritation of the sciatic nerve at the piriformis muscle level. Patients frequently present with unilateral gluteal pain that worsens with prolonged sitting, hip movement, or palpation over the piriformis locus. Although the neuropathic component of PS is attributed to sciatic nerve irritation, the somatic pain component is believed to arise from myofascial dysfunction within gluteal structures, particularly the piriformis muscle.

Recent clinical observations indicate that many patients diagnosed with PS also exhibit features of gluteus maximus myofascial pain syndrome (GM-MPS). The gluteus maximus muscle has a large fascial interface with the piriformis muscle, and nociceptive stimulation originating from this interface may contribute to persistent gluteal pain in PS. Despite this, the fascial contribution to symptom persistence remains poorly investigated, and therapeutic interventions are largely directed toward the piriformis alone.

Interfascial hydrodissection is an emerging ultrasound-guided technique in which liquid is injected between tissue planes to mechanically separate fascial layers, improve gliding, and modulate sensory nociceptive fibers. Dextrose solutions have been increasingly used in ultrasound-guided interfascial injections based on their proposed neuromodulatory and regenerative effects. However, evidence regarding its long-term efficacy in gluteal myofascial pain, particularly when coexisting with PS, is limited.

This prospective, randomized, double-blind clinical trial aims to evaluate the therapeutic effectiveness of interfascial hydrodissection using 10% dextrose solution between the gluteus maximus and piriformis muscles in patients with PS diagnosed through positive diagnostic injection response. Patients with ≥50% pain reduction one hour after diagnostic piriformis injection will be randomized into two treatment groups. Randomization will be performed by an independent co-investigator using a pre-prepared 1:1 allocation list. Outcome assessment will be conducted by an investigator blinded to treatment allocation. Patients will then be assigned to one of the following treatment groups: (1) ultrasound-guided interfascial hydrodissection and (2) dry needling of the gluteus maximus muscle.Both interventions will be performed under ultrasound guidance to ensure accuracy and standardization.

Outcome assessment will include numerical pain scoring, percentage pain reduction, and clinical improvement at one hour, one week, one month, and three months post-intervention. The first assessor will be blinded to treatment allocation, ensuring independent measurement of outcomes. It is hypothesized that interfascial hydrodissection will provide superior long-term pain relief compared with dry needling by separating adhered fascial planes, improving local mobility, and reducing nociceptive drive through dextrose-mediated neuromodulation.

If successful, this trial will provide the first structured evidence evaluating the role of gluteus maximus-piriformis fascial interface treatment in PS and may identify an overlooked pain generator in this common syndrome. Results could expand therapeutic options for PS, support broader application of interfascial hydrodissection, and contribute to clinical understanding of fascial pain mechanisms.

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.
Interventional

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.
42

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

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)
    • Istanbul
      • Istanbul, Istanbul, Turkey (Türkiye)
        • Istanbul University-Cerrahpasa, Cerrahpasa Faculty of Medicine
        • 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

Description

Inclusion Criteria:

  • Adults aged 18 to 75 years
  • Buttock pain with or without radiation to the lower extremity
  • Ability to understand and provide written informed consent

Exclusion Criteria:

  • Active lumbar radiculopathy
  • History of hip joint pathology or prior hip surgery
  • Previous injection or dry needling treatment to the gluteal region within the last 3 months
  • Coagulation disorders or use of anticoagulant therapy
  • Pregnancy
  • Local infection at the injection site
  • Inability to complete the study protocol or attend follow-up visits.

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

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Ultrasound-Guided Interfascial Hydrodissection
Ultrasound-guided interfascial hydrodissection is performed in the interfascial space between the gluteus maximus and piriformis muscles.
Procedure: Ultrasound-Guided Interfascial Hydrodissection
Ultrasound-guided interfascial hydrodissection is performed in the interfascial plane between the gluteus maximus and piriformis muscles.
Active Comparator: Ultrasound-guided gluteus maximus dry needling
Participants receive ultrasound-guided dry needling applied to the gluteus maximus muscle.
Procedure: Ultrasound-Guided Gluteus Maximus Dry Needling
Ultrasound-guided dry needling is performed on the gluteus maximus muscle without fluid administration.

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
Pain Intensity Assessed by Numeric Rating Scale
Time Frame: 3 months after the intervention
Pain intensity is assessed using the Numeric Rating Scale (NRS, 0-10) for pain at rest, during activity, at night, while standing, sitting, lying down, and for overall pain.
3 months after the intervention

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
Pain Intensity Assessed by Numeric Rating Scale
Time Frame: 1 week after the intervention
Pain intensity is assessed using the Numeric Rating Scale (NRS, 0-10) for pain at rest, during activity, at night, while standing, sitting, lying down, and for overall pain.
1 week after the intervention
Pain Intensity Assessed by Numeric Rating Scale
Time Frame: 1 month after the intervention
Pain intensity is assessed using the Numeric Rating Scale (NRS, 0-10) for pain at rest, during activity, at night, while standing, sitting, lying down, and for overall pain.
1 month after the intervention

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.
Istanbul University - Cerrahpasa

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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 (Estimated)

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.
March 26, 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.
June 28, 2026

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.
September 28, 2026

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).
December 24, 2025

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.
December 24, 2025

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.
January 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.
March 13, 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.
March 11, 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.
March 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.
  • CTFPIRHD2025

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

IPD Plan Description

Individual participant data sharing has not been decided at this stage. Although ethical approval for the study has been obtained, any potential data sharing will be considered in the future upon reasonable request and in accordance with participant consent and institutional policies.

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.

Clinical Trials on Piriformis Syndrome

Clinical Trials on Ultrasound-Guided Interfascial Hydrodissection

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Cookie Settings

We use cookies to ensure that we give you the best experience on our website. For more details carefully read our Privacy and Cookies Policy. ...>>>You can change your preferences or withdraw your consent at any time by deleting the cookies from your website or computer as described in the policy. Please accept it and choose your preferences by ticking the corresponding boxes in the "Manage Settings" section below. Please carefully read our Terms of Service before you proceed with using any part of this website.
«Manage Settings