Related Experiment Video
Updated: May 13, 2026
Minimally Invasive Treatment for Thoracolumbar Burst Fracture Using Sagittal Alignment Screws and A Trauma Reduction Device
Published on: November 8, 2024
Reinforcement of lumbosacral instrumentation using S1-pedicle screws combined with S2-alar screws
H Koller1, J Zenner, A Hempfing
1Werner-Wicker-Clinik, German Scoliosis Center, Im Kreuzfeld 4, 34537 Bad Wildungen, Germany. Heiko.koller@t-online.de
Objective:
Increasing construct stability of lumbosacral instrumentations using S2-ala screws as an alternate to iliac screws.
Indications:
Revision surgery after failed lumbosacral fusion; long instrumentations to the sacrum; L5-S1 fusion without anterior support.
Contraindications:
Lack of sacral bone stock.
Surgical Technique:
Midline approach. The entry point for S2-ala screws is caudal to the posterior S1 foramen and close to the lateral sacral crest. Screw tract preparation for S2-ala screws necessitates 30-45° angulation in the axial plane. Biplanar fluoroscopy with inlet and outlet views ensure screw accuracy. With S2-ala screws, bicortical fixation is the goal.
Postoperative Management:
Patients are mobilized under the surveillance of physiotherapists on day 1 and released from the hospital after 10 days. Clinical and radiographic controls are performed at 6, 12 and 24 months.
Results:
Retrospective review of 80 patients undergoing S2-ala screw fixation. Main diagnosis was degenerative lumbar instability, adult scoliosis, high-grade listhesis, and nonidiopathic scoliosis. In 66% of patients, the instrumentation using S2-ala screws was part of a major lumbosacral revision surgery. Follow-up averaged 26 months. There were no deaths or major neurovascular complications. First time fusion rate at L5-S1 was greater than 90%. Eight patients (10%) experienced a complication which could be related to the S2-ala screws. Out of 160 S2-ala screws, 16 screws were judged to cause focal irritation and were removed, indicating a survival rate of 90% for the S2-ala screw.
