Robot-assisted sacroiliac joint (SIJ) fusion surgery can, in about 1% of cases, injure the superior gluteal artery (SGA), but preoperative imaging, precise robot-assisted screw insertion and soft tissue protection can mitigate risks, according to a recently published study in the Journal of Neurosurgery: Case Lessons.

The study describes the case of an 80-year-old man who had endured 10 years of chronic low back pain he rated as an 8 out of 10. Conservative treatments had not provided suitable improvement, and pain significantly affected his day-to-day lifestyle.

A physical examination revealed left sacroiliac joint pain. Diagnostic imaging indicated SI joint dysfunction.

The decision was made to undertake a percutaneous, awake robot-assisted sacroiliac joint fusion.

During surgery, technical issues prevented direct docking on the iliac bone, and there was some tissue between the robot end effector and the iliac bone. Fluoroscopy and intraoperative CT confirmed appropriate placement of the instrumentation.

Days after discharge, the patient experienced postoperative left hip pain and bruising. Imaging showed an SGA branch pseudoaneurysm requiring coil embolization.

Endovascular coil embolization of the left SGA pseudoaneurysm was completed without complication 11 days after the initial SI joint fusion surgery. One month after the fusion surgery, the patient’s pain had improved and was managed by aspirin. Bruising from the left hip to the left ankle persisted.

Minimally invasive techniques have been shown to decrease risk of revision surgery, infection, instrumentation complications and postoperative opioid use, but complications still can occur. During SI joint fusion surgery, there have been instances of injury to the deep superior and superficial branches of the superior gluteal artery during the placement of sacroiliac screws.

The study, “Successful Coil Embolization of a Ruptured Pseudoaneurysm of the Superior Gluteal Artery After a Percutaneous Awake Robot-Assisted Sacroiliac Joint Fusion: Illustrative Case,” was co-authored by Shawn W. Adams, M.D., while completing a fellowship last year in deformity and minimally invasive complex spinal surgery at Duke University School of Medicine, Durham, North Carolina. Dr. Adams is now with Norton Leatherman Spine.

The sacroiliac joint connects the spine and pelvis. Degenerative sacroiliitis and injury can lead to lower back pain, requiring surgical stabilization. Robotic-assisted SI joint fusion has become increasingly popular as a treatment for SIJ dysfunction-related pain.

In the case of the 80-year-old patient, software error resulted in a plan to use traditional screws. However, during the procedure, sacroiliac screws were used. Because of the change, the robot failed to dock directly on bone, posing a potential risk of vascular injury.

In sacroiliac joint fusion, the deep superior and superficial branches of the superior gluteal artery can be injured during the placement of sacroiliac screws.

The authors concluded that “careful surgical planning, accurate screw placement, and the use of protective sheaths are crucial to prevent SGA injury during surgery for degenerative disease of the SIJ.”

Surgeons, the authors wrote, should have a comprehensive understanding of the SGA anatomy and its variants and must be proactive in addressing complications to ensure patient safety during these procedures.