"Piriformis Syndrome": Is It Only Piriformis?

Abstract

Dear Editor, Piriformis syndrome (PS) comprises symptoms like pain in the region of the sacroiliac joint, greater sciatic notch, piriformis muscle (PM), and occasionally sciatica [1]. Walking/stooping/lifting exacerbate the symptoms. Signs include piriformis tenderness, PM stretch pain, positive straight leg raise sign, gluteal atrophy and weakness [2]. PS accounts for 6–8% of low back pain cases [3]. Proposed mechanisms for PS include PM contracture/spasm from trauma/overuse/hypertrophy. Steroid/botulinum toxin injections form the mainstay of therapy [1]. We propose that gemelli and obturator internus (OI) are also part of myofascial pain syndrome (MPS) causing PS. We report the success of ultrasound-guided dry needling (USGDN) of gemelli and OI in relieving PS symptoms in a patient who had remained unresponsive to repeated piriformis injections. A 72-year-old radiologist presented with continuous pain (8–9 on Numerical Rating Scale [NRS]) in right buttock, radiating to ankle within 1–2 minutes of sitting/standing/assisted walking. Piriformis stretch test was positive and palpation showed right buttock tenderness. His symptoms had started with mobilization after 3 months of bed rest for L5 vertebral osteomyelitis following surgery for lumbar canal stenosis of 3 years with foot drop. Pain was unrelieved by neuromodulators (pregabalin, gabapentin), analgesics (100 mg extended-release tramadol, paracetamol 500 mg tds), computed tomography (CT), and ultrasonography (USG)-guided piriformis injections with steroid. His Patient Health Questionnaire (PHQ) [4] score was 10, indicating major depressive disorder and painDETECT [5] score was 16, indicating definite neuropathy. Magnetic resonance imaging showed discogenic, facetogenic, and failed back surgery syndrome (FBSS) pathologies, normal hip, and healed osteomyelitis. He was offered three treatment options: a medial branch block test followed by radiofreqency (RF) neurotomy for facet arthropathy, epidural injection for radiculopathy, and USGDN for MPS causing PS. He chose USGDN. High-frequency linear 6–13 MHz transducer of Sonosite TM …