An interventional study of Ultrasound-Guided Piriformis Injection in Piriformis Syndrome and Gluteal Pain, sponsored by Istanbul University - Cerrahpasa. Not yet recruiting at 1 site in Turkey (Türkiye). Open to participants aged 18 Years to 75 Years. Per ClinicalTrials.gov, last updated 2026-03-17.
Sponsored by Istanbul University - Cerrahpasa · Not applicable, Interventional, and Diagnostic
Piriformis syndrome is a clinical condition characterized by buttock pain and/or sciatic-like symptoms, and its diagnosis remains challenging because there is no universally accepted diagnostic standard. This study aims to evaluate the diagnostic accuracy of commonly used diagnostic criteria and clinical tests for piriformis syndrome. Participants with suspected piriformis syndrome will undergo standardized physical examination and assessment of predefined diagnostic criteria. Ultrasound-guided injection of 5 mL of 2% lidocaine into the piriformis muscle will be used as the reference diagnostic procedure. A reduction of 50% or more in pain after injection will be considered confirmation of piriformis syndrome. The diagnostic performance of clinical tests and diagnostic criteria will be analyzed accordingly.
Piriformis syndrome is one of the possible causes of buttock pain and sciatica-like symptoms; however, its diagnosis is often difficult because of symptom overlap with lumbar radiculopathy, sacroiliac joint disorders, and other musculoskeletal conditions. In clinical practice, several physical examination maneuvers and diagnostic criteria are used, but their diagnostic accuracy has not been sufficiently established.
The aim of this study is to evaluate the diagnostic accuracy of predefined diagnostic criteria and commonly used clinical tests for piriformis syndrome. Adult participants with suspected piriformis syndrome will be recruited prospectively. All participants will undergo a standardized clinical assessment including history taking, physical examination, and evaluation of predefined diagnostic criteria and provocation tests. Clinical examinations will be performed by two physicians according to the study protocol.
As the reference diagnostic procedure, participants will undergo ultrasound-guided injection of 5 mL of 2% lidocaine into the piriformis muscle. The injection will be performed by an experienced physician under ultrasound guidance. Pain severity will be assessed before and after the procedure. A decrease of 50% or more in pain following injection will be accepted as confirmation of piriformis syndrome.
The diagnostic performance of each clinical test and diagnostic criterion set will be evaluated against this reference standard. Sensitivity, specificity, predictive values, likelihood ratios, and overall diagnostic accuracy will be analyzed. The findings of this study are expected to contribute to the development of a more standardized, reliable, and clinically applicable diagnostic approach for piriformis syndrome.
58 studies on the registry are indexed under Piriformis Muscle Syndrome; 23 are open to participants now.
This study's planned enrollment of 75 is above the median of 42 across 52 interventional studies indexed under Piriformis Muscle Syndrome.
Browse Piriformis Muscle Syndrome studies →Istanbul University - Cerrahpasa is the lead sponsor of 699 studies on the registry; 213 are open to participants now.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants with suspected piriformis syndrome will undergo standardized clinical assessment and the diagnostic intervention defined as Ultrasound-Guided Piriformis Injection, consisting of ultrasound-guided injection of 5 mL of 2% lidocaine into the piriformis muscle.
Diagnostic Test: Ultrasound-Guided Piriformis Injection
Ultrasound-guided injection of 5 mL of 2% lidocaine into the piriformis muscle for diagnostic confirmation. A patient-reported pain reduction of 50% or more at 1 hour after injection will be considered confirmation of piriformis syndrome.
Diagnostic accuracy of clinical tests and diagnostic criteria for piriformis syndrome
Diagnostic accuracy of predefined clinical tests and diagnostic criteria will be evaluated using pain response to ultrasound-guided piriformis injection as the reference standard. A positive reference standard result will be defined as a patient-reported reduction of 50% or more in pain at 1 hour after injection compared with pre-injection pain. Participants with a positive reference standard result will be classified as having piriformis syndrome for the diagnostic accuracy analysis.
Time frame: Same day; pain response assessed 1 hour after injection
Plan to share: Undecided — The plan for sharing individual participant data has not yet been determined.
This study is not yet recruiting, as verified in Mar 2026. You cannot join it, but the record below documents what was studied.
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