Failed back syndrome or extra-spinal sciatica? Ischiofemoral syndrome as a cause of persistent radicular pain after 4 lumbar spine surgeries.

Most cases of sciatica are caused by compression of lumbar nerve roots, although some originate from extraradicular structures, such as in ischiofemoral impingement syndrome. We present the case of a 64-year-old man with a 10-year history of right-sided sciatic pain occurring only while seated. He underwent several lumbar surgeries for spinal stenosis (L4-L5, then L3-L4, and later L5-S1 with fusion to S1), as well as multiple infiltrations and pulsed radiofrequency, without improvement. Neurophysiological and imaging studies showed no significant compression, except for oedema at the ischial insertion of the quadratus femoris muscle. A diagnostic local anaesthetic infiltration temporarily resolved the pain, confirming ischiofemoral impingement syndrome. He was treated with osteotomy of the lesser trochanter, achieving complete pain resolution and functional recovery. This case highlights the importance of considering extraradicular causes in patients with persistent sciatic pain after spinal surgery.