A Novel Approach for Horizontal Sacral Insufficiency Fractures. Long Axis Kyphoplasty through Sacral Hiatus

Abstract

Introduction Sacral insufficiency fractures (SIF) may cause significant low back pain, limit daily living, and tend to be undetected. Effective pain management and early mobilization are mandatory to prevent complications. Percutaneous sacroplasty for treatment of SIF has gained interest recently. This technique provides safe, rapid, and prolonged pain relief, early mobilization, and functional recovery. Sacral kyphoplasty is percutaneous placement of bone cement into the sacral vertebra using inflatable tamps. Both sacroplasty and sacral kyphoplasty are used for vertical component of the SIF. Highly trabecular pattern of sacral bone and proximity of sacral foramina and sacral canal limit the use of these techniques to sacral ala. We have described a new technique for injection of PMMA into proximal sacral vertebra. Patient and Methods: A 50-year-old patient with SIF at S1–S2 level was selected for this procedure. The patient was placed prone on the operation table. She was sedated using IV midazolam and fentanyl. The fluoroscopy was positioned so that sacral foramina could be clearly visualized on AP and lateral views. A stab incision was made following local anesthesia at the level of sacral hiatus. Bone access needle was introduced into the sacral hiatus above the superior margin of the coccyx under fluoroscopic guidance, similar to epiduroscopy. Epidural space was traversed and the corpus of distal sacral vertebra was reached. Entry point was checked in AP and lateral views. Needle tip was advanced proximal to the fracture line, into the S1. Once the ideal position of the needle was confirmed, guide pin and a working cannula were inserted. Balloon tamp was inserted and was inflated with 1.5 mL contrast dye to no more than 250 psi. Fluoroscopic control was performed to make sure that the inflated balloon did not breach cortices. Bone tamps were deflated and removed. The void was filled with radio opaque bone cement proximal to distal as cannula was slowly pulled back. Migration and extravasation of the cement was checked with fluoroscopy. Results The surgical procedure was completed in 25 minutes. Total fluoroscopy time was 10 minutes. There were no intraoperative or postoperative complications. While in the PACU, the patient declared that her pain had alleviated by half. She could mobilize freely in her room 2 hours after the intervention. No cement extravasation occurred. 24 hours following the surgery, she was completely pain free and was discharged from the hospital. On her last follow-up, she was completely asymptomatic, ambulatory, and could perform her daily activities by herself. Conclusion Sacroplasty and sacral kyphoplasty are generally used for Denis Zone 1 fractures. Proximity of the sacral foramina and sacral canal cause clinicians to avoid cement injection into sacral vertebral bodies. This procedure is very rarely performed. Use of pedicles to reach vertebral corpus restricts surgeon's ability to position cannula and pedicle fracture is another risk. With our long axis technique, bone cement can be injected into the sacral body in a longitudinal fashion with multiple sacral levels being augmented in a single entry.