Spinal dysraphism and dislocated hip: Beware of anomalous sciatic nerve through Ilium, a case report

RATIONALE: The sciatic nerve runs a predictable course combining L4-S3 nerve roots through the true pelvis and under the greater sciatic notch. There are reports of bony protuberances from the sacrum and ilium in cases of spinal dysraphism; however advanced imaging, treatment, or outcomes are not described. There are no cases with associated fibular hemimelia in the current literature. PATIENT CONCERNS: This is a 4-year-old girl with tethered cord, acetabular dysplasia with hip subluxation, congenital short femur, anterior cruciate ligament (ACL) deficiency, and fibular hemimelia with her sciatic nerve coursing through the ilium. DIAGNOSIS: Aberrant course of the sciatic nerve through the ilium in the setting of spinal dysraphism. OUTCOMES: The hip subluxation was treated with a femoral varus derotation osteotomy and Salter osteotomy with transposition of the sciatic nerve into the greater sciatic notch resulting in a stable hip with no sciatic nerve symptoms at last follow-up. LESSONS: The combination of spinal dysraphism with acetabular dysplasia should be a warning for anomalous sciatic nerveanatomy, possibly through the ilium. Preoperative imaging (MRI, CT scan) may be obtained and carefully reviewed for the course of the sciatic nerve prior to pelvic or femoral osteotomy. Decompressing the sciatic nerve from the aberrant foramen may be considered as part of the procedure.