CT-guided steroid injections for the diagnosis and management of piriformis syndrome

Abstract

Objectives: Piriformis syndrome (PS) is an extra-spinal tunnel neuropathy affecting the sciatic nerve. While typically diagnosed clinically, with confirmation through exclusion of other conditions, accurate diagnosis remains challenging. This study assesses the clinical outcomes of computed tomography (CT)-guided corticosteroid injection for suspected PS, considering its potential role as both a diagnostic and a therapeutic intervention. Materials and Methods: We conducted a retrospective review of 32 patients suspected to have PS, based on clinical presentation and examination findings, who underwent CT-guided steroid injections between July 2013 and February 2020. Effectiveness was evaluated qualitatively through clinic letters from patient reviews with a mean follow-up of 5 months (range 3–7) Results: Thirty-two patients received 44 injections. The cohort had an average age of 45 years, with many being physically active. Initial follow-up showed that 56% experienced pain relief, though 16% of these cases were short-lived. About 19% reported partial benefit, while 31% reported no improvement. Repeat injections were performed on nine patients, with some undergoing up to two repeat procedures. About 47% of patients were discharged following injections, repeats, or surgery, while 53% required further specialist input. Conclusion: CT-guided corticosteroid injections appear to be a valuable management tool for diagnosis and treatment of PS, particularly when conservative management fails. However, the long-term benefits are inconsistent, highlighting the need for a more standardized treatment pathway. Given the high degree of diagnostic uncertainty and lack of accurate diagnostic tools for PS, we propose the use of local anesthetic and steroid injections as a diagnostic approach, as well as a management option.