Unusual course of the superior gluteal artery between the roots of the lumbosacral trunk: case report and potential clinical implications

The superior gluteal artery is the largest branch of the internal iliac artery and usually runs posteriorly between the lumbosacral trunk and the S1 root of lumbosacral plexus, medially to the sacroiliac joint. It emerges from the pelvis through the greater sciatic foramen, superior to the piriformis muscle, and immediately splits into superficial and deep branches for the gluteal region. During routine academic activities, the course of the superior gluteal artery differed from the usual pattern. In this case, the artery passed between L4 and L5 roots of the lumbosacral plexus. The union of these roots to form the lumbosacral trunk, which typically occurs above the sacroiliac joint, occurred below this limit, that is, inside the pelvic cavity. This case is relevant because of its proximity to the sacroiliac joint, which may lead to iatrogenic complications in routine procedures such as percutaneous sacroiliac joint fusion. Anatomical variability among individuals should be considered in preoperative planning, as deep branches of the superior gluteal artery may be located within the safe zone for screw insertion.