S2-AI screw placement with the aide of electronic conductivity device monitoring: a retrospective analysis

Eur Spine J. 2017 Nov;26(11):2941-2950. doi: 10.1007/s00586-017-5242-0. Epub 2017 Aug 1.


Study design: A retrospective analysis of two consecutive patients who underwent a novel surgical technique.

Objective: A report of a novel surgical technique utilizing an electronic conductivity device guidance to aide placement of S2-Alar-Iliac (S2-AI) instrumentation. Electronic conductivity guidance for instrumentation of the thoracolumbar spine is an accepted means of improving intraoperative accuracy. Although commercially available for percutaneous techniques, there is a paucity of literature regarding its use. Percutaneous implantation of S2-AI screws has been previously described as another technique surgeons can avail, primarily employing fluoroscopy as a means of intraoperative feedback. We describe a novel technique that utilizes electronic conductivity as an added feedback measure to increase accuracy of percutaneous S2-AI fixation.

Methods: Two patients were treated by the senior author (FAS) who underwent surgery employing S2-AI fixation utilizing an electronic conductivity device (Pediguard cannulated probe, Spineguard, Paris, France). The surgical technique, case illustrations, and radiographic outcomes are discussed.

Results: Stable and accurate fixation was attained in both patients. There were no peri-operative complications related to hardware placement.

Conclusion: To the authors' knowledge, this is the first reported literature combining S2-AI screws with electronic conductivity for immediate intraoperative feedback. This technique has the opportunity to provide surgeons with increased accuracy for placement of S2-AI screws while improving overall radiation safety. This feedback can be particularly helpful when surgeons are learning new techniques such as placement of S2AI screws.

Keywords: Lumbosacral fusion; MIS; Pelvic fixation; S2-AI.

MeSH terms

  • Electric Conductivity*
  • Humans
  • Ilium / surgery*
  • Monitoring, Intraoperative / methods*
  • Pedicle Screws*
  • Retrospective Studies
  • Sacrum / surgery*
  • Spinal Fusion / methods*