Piriformis and Gluteal Muscle Thickness in Patients With Unilateral Greater Trochanteric Pain Syndrome

Observational Assessment of Deep Gluteal Syndrome and Bilateral Piriformis, Gluteus Medius, and Gluteus Maximus Muscle Thickness Using Ultrasonography in Patients With Unilateral Greater Trochanteric Pain Syndrome

This study aims to evaluate muscle thickness in patients with unilateral Greater Trochanteric Pain Syndrome using ultrasonography and to compare these findings with healthy individuals. The primary objective is to determine whether piriformis muscle thickness differs between patients and controls. Secondary objectives include assessing gluteus medius and gluteus maximus muscle thickness, side-to-side differences in piriformis and gluteal muscle thickness, and the presence of Deep Gluteal Syndrome.

Study Overview

• Status: Completed
• Conditions: Gluteal Tendinopathy; Greater Trochanteric Pain Syndrome; Deep Gluteal Syndrome

Detailed Description

This observational cross-sectional study investigates ultrasonographic muscle morphology and associated clinical findings in patients with unilateral Greater Trochanteric Pain Syndrome (GTPS), focusing on piriformis and gluteal muscle thickness, symptom severity, and Deep Gluteal Syndrome-related findings.

Participants with unilateral GTPS and healthy controls are recruited from outpatient clinical settings. The clinical diagnosis of Greater Trochanteric Pain Syndrome is based on the presence of lateral hip pain in combination with at least two of the following findings: tenderness over the greater trochanter on palpation, pain during a 30-second single-leg stance test, or supportive ultrasonographic findings.

Ultrasonographic evaluations are performed bilaterally to measure piriformis, gluteus medius, and gluteus maximus muscle thickness. For each muscle, three measurements are obtained, and the mean value is used for analysis. Inter-side differences between affected and unaffected hips in the GTPS group and between both hips in the control group are calculated to assess asymmetry.

In the control group, the mean values of both hips are calculated and used as reference values. Comparisons are performed between affected and unaffected hips within the patient group. In addition, muscle thickness of the affected and unaffected hips in the GTPS group is compared separately with the control group mean values for each muscle. Inter-side differences in muscle thickness are also compared between patients and healthy controls. Trochanteric bursal fluid and Doppler signal changes are also evaluated using ultrasonography.

The presence of Deep Gluteal Syndrome is determined based on clinical criteria, defined as at least one clinical finding together with at least two positive standardized clinical provocation tests. Patients are categorized as Deep Gluteal Syndrome-positive or negative accordingly.

Symptom severity is assessed using the VISA-G (Victorian Institute of Sport Assessment-Gluteal) questionnaire. Correlation analyses are performed to evaluate the association between VISA-G scores and inter-side differences in muscle thickness.

• Study Type: Observational
• Enrollment (Actual): 60

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Ankara, Turkey (Türkiye), 06170
    • Ankara Etlik City Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

Adults with unilateral Greater Trochanteric Pain Syndrome and healthy individuals without hip pain or known musculoskeletal disorders are being recruited. Participants are evaluated using ultrasonography in an outpatient clinical setting.

Description

Inclusion Criteria:

• Adults aged 18 years or older
• Diagnosis of unilateral Greater Trochanteric Pain Syndrome

Exclusion Criteria:

• Presence of lumbar radiculopathy
• Presence of hip or spinal osteoarthritis
• History of lumbar spine or lower extremity surgery
• Presence of neurological disorders affecting muscles or peripheral nerves
• Pregnancy
• Presence of cognitive impairment or neuropsychiatric conditions limiting participation
• Unwillingness to participate
• Regular participation in physical exercise (defined as more than two sessions per week)

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
GTPS Patients; Patients with unilateral Greater Trochanteric Pain Syndrome evaluated with ultrasonography
Healthy Controls; Healthy individuals without hip pain or known musculoskeletal disorders, evaluated using ultrasonography

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Piriformis Muscle Thickness	Comparison of piriformis muscle thickness between patients with unilateral Greater Trochanteric Pain Syndrome and healthy controls using ultrasonography	At baseline

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Gluteus Medius and Gluteus Maximus Muscle Thickness	Comparison of gluteus medius and gluteus maximus muscle thickness between patients with unilateral Greater Trochanteric Pain Syndrome and healthy controls using ultrasonography.	At baseline
Side-to-Side Muscle Thickness Comparison	Within-group comparison of piriformis, gluteus medius, and gluteus maximus muscle thickness between affected and unaffected sides in patients with unilateral Greater Trochanteric Pain Syndrome.	At baseline
Trochanteric Bursa and Doppler Findings	Assessment of trochanteric bursal fluid and Doppler signal changes in patients with Greater Trochanteric Pain Syndrome using ultrasonography.	At baseline
Prevalence of Deep Gluteal Syndrome	Assessment of the presence of Deep Gluteal Syndrome in patients with Greater Trochanteric Pain Syndrome based on clinical evaluation and standardized provocation tests.	At baseline
Correlation Between VISA-G Score and Hip Muscle Thickness Asymmetry	Correlation between VISA-G score and inter-side muscle thickness differences of piriformis, gluteus medius, and gluteus maximus measured by ultrasonography in the patient group.	At baseline
Inter-side difference in muscle thickness between patients and controls	Comparison of inter-side differences in piriformis, gluteus medius, and gluteus maximus muscle thickness between patients with unilateral Greater Trochanteric Pain Syndrome and healthy controls using ultrasonography	At baseline

Collaborators and Investigators

• Sponsor: Ankara Etlik City Hospital

Publications and helpful links

General Publications

• Whittaker JL, Emery CA. Sonographic measures of the gluteus medius, gluteus minimus, and vastus medialis muscles. J Orthop Sports Phys Ther. 2014 Aug;44(8):627-32. doi: 10.2519/jospt.2014.5315. Epub 2014 Jul 16.
• Othman IK, Raj NB, Siew Kuan C, Sidek S, Wong LS, Djearamane S, Loganathan A, Selvaraj S. Association of Piriformis Thickness, Hip Muscle Strength, and Low Back Pain Patients with and without Piriformis Syndrome in Malaysia. Life (Basel). 2023 May 18;13(5):1208. doi: 10.3390/life13051208.
• Firat A, Veizi E, Karaman Y, Alkan H, Sahin A, Tolunay T, Kilicarslan K. Unrepaired Trochanteric Bursae as a Risk Factor for Deep Gluteal Syndrome After Total Hip Arthroplasty: A Prospective Randomized Controlled Trial. J Arthroplasty. 2024 Apr;39(4):1025-1030. doi: 10.1016/j.arth.2023.10.049. Epub 2023 Nov 2.
• Geler Kulcu D. Deep Gluteal syndrome: An underestimated cause of posterior hip pain. Turk J Phys Med Rehabil. 2024 Feb 1;70(1):4-16. doi: 10.5606/tftrd.2024.14668. eCollection 2024 Mar.
• Speers CJ, Bhogal GS. Greater trochanteric pain syndrome: a review of diagnosis and management in general practice. Br J Gen Pract. 2017 Oct;67(663):479-480. doi: 10.3399/bjgp17X693041. No abstract available.

Study record dates

Study Major Dates

• Study Start (Actual): December 2, 2025
• Primary Completion (Actual): March 31, 2026
• Study Completion (Actual): March 31, 2026

Study Registration Dates

• First Submitted: March 27, 2026
• First Submitted That Met QC Criteria: March 30, 2026
• First Posted (Actual): April 3, 2026

Study Record Updates

• Last Update Posted (Actual): April 13, 2026
• Last Update Submitted That Met QC Criteria: April 8, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Musculoskeletal Ultrasound; Hip Pain; Muscle Thickness; Greater Trochanteric Pain Syndrome; Deep Gluteal Syndrome; Piriformis Muscle; Gluteal Muscle Thickness
• Additional Relevant MeSH Terms: Hip socket neuropathy
• Other Study ID Numbers: AEŞH-BADEK1-2025-015

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No