A rare cause of non-discogenic sciatica; musculus gemellus inferior: A case report.

Herein, we report a 51-year-old female with complaint of right sciatica. According to physical examination, the etiology was suspected as piriformis syndrome. Therefore, piriformis injection was administered and piriformis stretching exercises were recommended.However the complains did not resolve. Magnetic resonance imaging showed hyperintensity of the right inferior musculus gemellus. One of the main causes of extra-spinal sciatica is piriformis syndrome. However, other pelvic muscles anatomically near the sciatic nerve are often overlooked. Magnetic resonance imaging is useful in the differential diagnosis from intractable piriformis syndrome, particularly in cases resistant to treatment.