Ultrasonographic Evaluation of the Sciatic Nerve in Patients With Piriformis Syndrome

Summary

Piriformis syndrome (PS) is defined as a neuropathy of entrapment resulting from compression and irritation of the sciatic nerve at the level of the piriformis muscle (PM) at the pelvic outlet, causing sciatica radiating to the leg. The neuropathic component of PS is the compression of the sciatic nerve in or around the PM, while the primary cause of the somatic component is myofascial pain of the PM. PS accounts for 6-8% of all hip and sciatic pain cases. It is more common in middle-aged patients, and the most common etiological cause is trauma. There are various methods for the diagnosis of Piriformis Syndrome. Clinically, tenderness on palpation of the PM is the most common symptom. The FAIR test (passive flexion abduction and internal rotation of the hip), the Freiberg test (forceful internal rotation of the thigh in the supine position), the Pace test (abduction of the leg against resistance while sitting) and the Beatty maneuver (active abduction of the thigh on the affected side in the lateral decubitus position) are maneuvers that help in diagnosis. It is known that there is a delay in proximal nerve conduction (H-reflex) on the pathological side compared to the healthy side in the FAIR maneuver on EMG in PS, and it is not a sufficient test for diagnosis alone. Some studies have reported increased piriformis thickness on the pathological side in MRI. None of these clinical and imaging methods are sufficient for diagnosis alone, and today ultrasonography (US) has become one of the most important imaging methods for musculoskeletal clinicians in the diagnosis of PS. Imaging with US and the diagnostic injection test applied to the piriformis muscle with US guidance are quite important for diagnosis. There are a number of studies in the literature evaluating PM with US. These studies have shown that the piriformis muscle thickness and echogenicity increase on the pathological side. However, there is a lack of studies in the literature focusing on the evaluation of the sciatic nerve with US in patients with PS. Our aim in this study is to compare the thickness of the PM and the sciatic nerve by measuring US on both the pathological and painless sides in patients with unilateral hip pain who were diagnosed with PS clinically, to record the variations present in the sciatic nerve, and to determine whether the myofascial pain or the neuropathic component is dominant in the disease.

Conditions

• Sciatica
• Piriformis Muscle Syndrome

Interventions

OTHER

Ultrasound

The ultrasound probe will be placed parallel to the body of the piriformis muscle on an imaginary line drawn from the sacrum to the greater trochanter of the femur. This area is also the sensitive area of the patients during the examination with pressure, and when the US probe is in this position, the subcutaneous fat tissue, gluteus maximus muscle, piriformis muscle, and the upper and lower borders of the sciatic nerve will be displayed in order from superficial to deep. First, the maximum thickness of the piriformis muscle body will be measured, then the thickness of the sciatic nerve will be measured, and the same measurements will be applied to the patient's asymptomatic hip, and the measurements will be recorded.

Sponsors & Collaborators

• Istanbul Physical Medicine Rehabilitation Training and Research Hospital

  collaborator OTHER_GOV

• Istanbul University - Cerrahpasa

  lead OTHER

Principal Investigators

• Selim Sezikli · Istanbul Physical Medicine Rehabilitation Training and Research Hospital

Eligibility

Min Age

18 Years

Max Age

70 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2024-12-01

Primary Completion

2025-04-01

Completion

2025-04-01

Countries

• Turkey (Türkiye)

Study Locations