First clinical results of a novel minimally-invasive fusion system for the sacroiliac joint.

Background: Sacroiliac joint (SIJ) painful dysfunction is a common source of low back pain (LBP). Several surgical treatment options for SIJ fusion were described. A promising treatment option with demonstrated clinical improvement is the minimally-invasive SIJ fusion.

Objective: The aim of this case study was to document the effectiveness and safety of the new SIJ system (Torpedo®) over a period of 6 months after the minimally invasive implantation.

Methods: Patients with failed conservative treatment of painful SIJ dysfunction were enrolled successively in two centers. The Diagnosis was made by positive response to SIJ-injection with local anesthetic and at least by two positive SIJ provocation tests. The Torpedo® Implant system was used for the implantation. This workpiece made of titanium alloy is characterized by a helical profile geometry (CST: chronical spinal turn) with a hydrophilic surface. The evaluated endpoints LBP and grade of disability were assessed using a 0-10 numerical rating scale (NRS), and Oswestry Disability Index (ODI) preoperatively and at one, three and six months postoperatively.

Results: 15 patients (10 female, 5 male; mean age 59 ± 13 years) were operated on one after the other. The pain intensity decreased in all 15 patients. After 6 months, a decrease in the median values of 70% (quartiles 1-3: 65-79%) was calculated. The median values of the Oswestry Disability Index after 6 months were 62% (quartiles 1-3: 53-67) lower than before the operation. Before surgery, 13 patients (87%) were taking opioids for pain management. Six months after the operation, opioids were only needed by 3 patients (20%). Implant malpositioning was not detected on plain radiograph. No surgical site infections or perioperative complications occurred.

Conclusions: The clinical improvement in early follow up and the absence of surgery related complications demonstrate a high grade of device-related safety and effectiveness of the treatment with a novel minimally-invasive SIJ fusion system.