Robotic-guided sacro-pelvic fixation using S2 alar-iliac screws: feasibility and accuracy
- 586 Downloads
To review our experience with robotic guided S2-alar iliac (S2AI) screw placement.
We retrospectively reviewed patients who underwent S2AI fixation with robotic guidance. Screw placement and deviation from the preoperative plan were assessed by fusing preoperative CT (with the planned S2AI screws) to postoperative CT. The software’s measurement tool was used to compare the planned vs. actual screw placements in axial and lateral views, at entry point to the S2 pedicle and at a 30 mm depth at the screws’ mid-shaft, in a resolution of 0.1 mm. Medical charts were reviewed for technical issues and intra-operative complications.
35 S2AI screws were reviewed in 18 patients. The patients’ mean age was 60 years. No intra-operative complications that related to the placement of S2AI screws were reported and robotic guidance was successful in all 35 screws. Post-operative CT scans showed that all trajectories were accurate. No violations of the iliac cortex or breaches of the anterior sacrum were noted. At the entry point, the screw deviated from the pre-operative plan by 3.0 ± 2.2 mm in the axial plane and 1.8 ± 1.6 mm in the lateral plane. At 30 mm depth, the screw deviated from the pre-operative plan by 2.1 ± 1.3 mm in the axial plane and 1.2 ± 1.1 mm in the lateral plane.
Robotic guided S2AI screw placement is feasible and accurate. No screw malpositions or complications that related to the placement of S2AI screws occurred in this series. Larger studies are needed to assess the long-term clinical outcomes of robotic guided sacral-pelvic fixation.
KeywordsS2-alar iliac screw Robotic guidance Accuracy Adult spinal deformity
We thank Josh Lieberman for creating the drawing of S2AI screws and Dr. Samuel Bederman for his help with the intra-operative photos.
Compliance with ethical standards
Conflict of interest
Xiaobang Hu received a travel support from Mazor Robotics in 2011. Isador H. Lieberman receives royalty, intellectual property rights, consulting fee and ownership interest from Mazor Robotics.
Source of funding
No funds were received in support of this work. The device that is the subject of this manuscript is FDA-approved for this indication. This study has been approved by Texas Health Resources IRB.
- 5.Polly DW, Jr (2015) The Sacroiliac joint and long lumbosacral fusions. surgery for the painful, dysfunctional sacroiliac joint. Springer, pp 151–158Google Scholar
- 8.Lieberman IH, Togawa D, Kayanja MM, Reinhardt MK, Friedlander A, Knoller N, Benzel EC (2006) Bone-mounted miniature robotic guidance for pedicle screw and translaminar facet screw placement: Part I—Technical development and a test case result. Neurosurgery 59:641–650 (discussion 641–650)Google Scholar
- 9.Togawa D, Kayanja MM, Reinhardt MK, Shoham M, Balter A, Friedlander A, Knoller N, Benzel EC, Lieberman IH (2007) Bone-mounted miniature robotic guidance for pedicle screw and translaminar facet screw placement: part 2—Evaluation of system accuracy. Neurosurgery 60:ONS129-139 (discussion ONS139)Google Scholar
- 10.Ray WZ, Ravindra VM, Schmidt MH, Dailey AT (2013) Stereotactic navigation with the O-arm for placement of S-2 alar iliac screws in pelvic lumbar fixation. J Neurosurg 18:490–495Google Scholar
- 13.Ughwanogho E, Flynn JM (2010) Current navigation modalities in spine surgery. Univ Pa Orthop J 20:65–69Google Scholar
- 16.Putzier M, Strube P, Cecchinato R, Lamartina C, Hoff E (2014) A new navigational tool for pedicle screw placement in patients with severe scoliosis: a pilot study to prove feasibility, accuracy, and identify operative challenges. J Spinal Disord TechGoogle Scholar
- 17.Bederman SS, Hahn P, Colin V, Kiester DP, Bhatia NN (2015) Robotic guidance for S2-alar-iliac screws in spinal deformity correction. J Spinal Disord TechGoogle Scholar