Diagnostic Accuracy of Clinical Tests and Diagnostic Criteria for Piriformis Syndrome

Official title

Evaluation of the Diagnostic Accuracy of Diagnostic Criteria and Clinical Tests for Piriformis Syndrome

Overview

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.

Detailed description

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.

Interventions

• 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.

Primary outcome measures

• Diagnostic accuracy of clinical tests and diagnostic criteria for piriformis syndrome [Time frame: Same day; pain response assessed 1 hour after injection]

Eligibility criteria

Inclusion criteria

• Adults aged 18 to 75 years
• Presentation with gluteal pain
• Pain on palpation in the piriformis region

Exclusion criteria

• History of injection to the lumbar, hip, or gluteal region within the last 3 months,including steroid, hyaluronic acid, or similar injections
• History of hip surgery
• Presence of active inflammatory rheumatic disease, including rheumatoid arthritis, ankylosing spondylitis, polymyalgia rheumatica, vasculitis, or similar conditions
• Active skin or subcutaneous soft tissue infection in the gluteal region
• Use of anticoagulant therapy that may contraindicate injection
• Presence of a bleeding disorder
• Uncontrolled diabetes mellitus and/or hypertension
• History of neurological disease
• Pregnancy or lactation
• Presence of a psychiatric disorder
• Known allergy to the injection agents
• History of malignancy

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

N/A

Model

Single group

Masking

Open label

Primary purpose

Diagnostic

Study locations

Turkey (Türkiye) · 1 center

• Istanbul University-Cerrahpasa, Cerrahpasa Medical Faculty — Istanbul

Publications

• Misirlioglu TO, Akgun K, Palamar D, Erden MG, Erbilir T. Piriformis syndrome: comparison of the effectiveness of local anesthetic and corticosteroid injections: a double-blinded, randomized controlled study. Pain Physician. 2015 Mar-Apr;18(2):163-71. PMID 25794202
• Hopayian K, Danielyan A. Four symptoms define the piriformis syndrome: an updated systematic review of its clinical features. Eur J Orthop Surg Traumatol. 2018 Feb;28(2):155-164. doi: 10.1007/s00590-017-2031-8. Epub 2017 Aug 23. PMID 28836092
• Michel F, Decavel P, Toussirot E, Tatu L, Aleton E, Monnier G, Garbuio P, Parratte B. The piriformis muscle syndrome: an exploration of anatomical context, pathophysiological hypotheses and diagnostic criteria. Ann Phys Rehabil Med. 2013 May;56(4):300-11. doi: 10.1016/j.rehab.2013.03.006. Epub 2013 Apr 30. PMID 23684469

Identifiers

NCT: NCT07473349 · CTFPIR2025

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗