Introduction: The B-Twin, An Expandable Spinal Fusion System (ESFS) was designed to be introduced within the lumbar intervertebral space using a minimal invasive technique without lateral spinal bony mass compromising. The achieved vertebral fixation enables fusion to take over. Up to now, over 800 surgeries have been performed worldwide. A preliminary 18 months international study follow up results are hereby reported.

Methods: Ninety five degenerative disc disease patients were operated on. Involved interspace were between L3-S1 level. Patients average age was 52 year-old. Ninety three patients underwent surgery at 1 level, of which 75 Procedures were performed via posterior approach, 2 via anterior approach, and 16 percutaneously. Discectomy, end plate removal, posterior iliac or cadaveric bone grafts were implanted within the inter-vertebral space around and in-between the implants. The longer follow up period is of 18 months, performed according to an investigation protocol that dictates follow up visiting rate, pain evaluation criteria based on Oswestry questionnaire, VAS/10 Box Scale measurement and radiographic pre and postoperatively parameters.

Results: Safety and efficacy during and post surgery were preliminary proved based on 18 months follow up period. No clinical complication, deterioration, mortality and/or implant failure were reported. Flexion/extension x-rays demonsrate fixation stability. VAS score for pain was dropped from approximately 8 preoperatively to a 3.8 average score within 1.5 to 8 months postoperative time period.

Conclusion: A safe minimal invasive surgical technique for discectomy, bone grafting and fixation device implantation (5mm reduced up to 15mm expanded) without surrounding bony structure compromising and improvement of clinical status are enabled and facilitated.