Current evidence and future applications for robotics in spinal surgery

L-R: Ronald A Lehman and Nathan J Lee
L-R: Ronald A Lehman and Nathan J Lee

While robotic technology is still in its infancy, current evidence suggests a promising future for its application in spine surgery, argue Ronald A Lehman and Nathan J Lee. Here, for Spinal News International, they discuss the results of recent studies into the safety and efficacy of this emerging technology and conclude that there is an “attractive future” for robotics in spine surgery, defined by increased accuracy, enhanced safety, and reduced costs.

Robot-assisted platforms are currently at the leading edge of innovation in spine surgery. This emerging technology is attractive to both surgeons and patients for a number of potential reasons. These include increased accuracy of pedicle screw placement versus historical freehand techniques, minimally invasive applications (small incisions and less dissection, retraction, bleeding, and infection), decreased radiation exposure to the operator versus traditional fluoroscopically-assisted techniques, and reduced human error including fatigue, tremor, and precise repetition. Robotic technology has only been recently introduced in spine surgery, but current literature is already demonstrating promise.

The improved accuracy and precision of pedicle screw placement is perhaps the most lauded aspect of robot-assisted surgery. For the conventional freehand technique, the reported pedicle screw misplacement rates in the thoracolumbar spine ranges from 2–31%.1–4 The majority of current literature suggests that robotic-assisted placement of pedicle screws is comparable or significantly higher. Devito et al performed a multicentre, retrospective review evaluating the placement of 3,271 pedicle screws. Based on postoperative CT analysis, 98.3% of screws were found to be within the 2mm “safe zone,” and only 1.7% of screws had a breach greater 2mm.5 In another retrospective review, Kantelhardt et al compared conventional freehand versus open robotic-assisted versus percutaneous robotic-assisted pedicle screw placement techniques and found an accuracy rate of 94.5% for the combined robotic-assisted group versus 91.4% for the freehand group.6 A recent meta-analysis of six randomised controlled trials demonstrated superior Grade A accuracy (as described by the Gerztbein-Robbins classification) and fewer proximal facet joint violations in the robot-assisted group versus conventional freehand group.7 Recently, our group published a propensity-matched analysis on the accuracy of free-hand versus robotic guidance for placement of S2 alar-iliac screws. There was no significant difference in the overall accuracy (94.9% vs. 97.8%, respectively).8

There is good consensus within the literature that there is reduced time to radiation during robotic-assisted surgeries compared to conventional techniques. In a prospective randomised trial, Roser et al demonstrate an average radiation time of 15.98 seconds and 31.5 seconds for the robotic-assisted and the traditional freehand technique, respectively.9,10 Similarly, a retrospective cohort study demonstrated an average of 34 seconds in the robotic-guided group compared to 77 seconds in conventional cases. Interestingly, a single-centre prospective randomised controlled study shows no significant difference in intraoperative radiation time between freehand and robotic groups.11 In comparison to robot-assisted surgery, the freehand technique necessitates fluoroscopic confirmation, which may increase radiation to the patients.

Many articles comparing robotics to open freehand surgeries show reductions in length of stay. In a retrospective study comparing open robotic versus open freehand cohorts, the average length of stay was 11.6 vs. 14.6 respectively.6 In a prospective randomised clinical trial, the average length of hospital stay for the robotic-guided minimally invasive group versus the fluoroscopic guided open surgery group was 6.8 and 9.4 days, respectively.10 It is likely that these reductions in hospital stay are influenced by the minimally invasive nature of the robotic surgical approach as opposed to other technical aspects of the robot. Nevertheless, these finding suggest a potential area that may offset the high costs of owning and maintaining robotic systems.

Early applications of this technology have primarily focused on the placement of pedicle screws, which is arguably one of the most technically demanding and high-risk aspects of spine surgery. Overall, current literature suggests that robotic spine surgery can be a safe and efficient method for screw placement.12 Spine surgeons should familiarise themselves with this developing technology since its applications will likely expand beyond the scope of pedicle screws. Our research group published a study demonstrating that a bone-mounted miniature robotic-guided system was able to achieve spinopelvic fixation using S2 alar-iliac screws safely and reliably.13 Next steps may include further integration of robotics in the workflow of deformity cases. Robotic systems may be equipped to place not only screws but also customised rod constructs. MRI-based navigation could enable soft tissue handling, including disc work and tumor resections.14–16

When new technologies are adopted in healthcare, it should provide a path to higher quality care for the patient in a safer and more cost-effective manner. For this reason and the growing evidence that support these goals, robotic spine surgery remains an attractive future that may have the potential to change the landscape of spine surgical care. As the data supporting the clinical and economical value grows, it is conceivable that the use of robotic-assisted technology will be considered as “standard of care.”

Ronald A Lehman is a professor of Orthopaedic Surgery at the New York-Presbyterian Hospital in New York, USA.
Nathan J Lee is an Orthopaedic Surgery resident at the New York-Presbyterian.


  1. Modi HN, Suh SW, Hong JY, Yang JH. Accuracy of thoracic pedicle screw using ideal pedicle entry point in severe scoliosis. Clinical Orthopaedics and Related Research. 2010;468(7):1830–7.
  2. Kim YJ, Lenke LG, Bridwell KH, et al. Free hand pedicle screw placement in the thoracic spine: is it safe? Spine. 2004;29(3):333-42; discussion 42.
  3. Karapinar L, Erel N, Ozturk H, Altay T, Kaya A. Pedicle screw placement with a free hand technique in thoracolumbar spine: Is it safe? Journal of Spinal Disorders & Techniques. 2008;21(1):63–7.
  4. Parker SL, McGirt MJ, Farber SH, et al. Accuracy of free-hand pedicle screws in the thoracic and lumbar spine: analysis of 6,816 consecutive screws. Neurosurgery. 2011;68(1):170–8; discussion 8.
  5. Devito DP, Kaplan L, Dietl R, et al. Clinical acceptance and accuracy assessment of spinal implants guided with SpineAssist surgical robot: Retrospective study. Spine. 2010;35(24):2109–15.
  6. Kantelhardt SR, Martinez R, Baerwinkel S, et al. Perioperative course and accuracy of screw positioning in conventional, open robotic-guided and percutaneous robotic-guided, pedicle screw placement. European Spine Journal: Official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society. 2011;20(6):860–8.
  7. Gao S, Lv Z, Fang H. Robot-assisted and conventional freehand pedicle screw placement: A systematic review and meta-analysis of randomised controlled trials. European Spine Journal. 2018;27(4):921–30.
  8. Shillingford JN, Laratta JL, Park PJ, et al. Human versus robot: A propensity-matched analysis of the accuracy of free hand versus robotic guidance for placement of S2 alar-iliac (S2AI) screws. Spine. 2018;43(21):E1297–e304.
  9. Roser F, Tatagiba M, Maier G. Spinal robotics: Current applications and future perspectives. Neurosurgery. 2013;72 Suppl 1:12–8.
  10. Hyun SJ, Kim KJ, Jahng TA, Kim HJ. Minimally invasive robotic versus open fluoroscopic-guided spinal instrumented fusions: A randomised controlled trial. Spine. 2017;42(6):353–8.
  11. Ringel F, Stuer C, Reinke A, et al. Accuracy of robot-assisted placement of lumbar and sacral pedicle screws: A prospective randomised comparison to conventional freehand screw implantation. Spine. 2012;37(8):E496–501.
  12. Tan LA, Lehman RA. Robotic-assisted spine surgery using the Mazor XTM System: 2-dimensional operative video. Operative Neurosurgery (Hagerstown, Md). 2019;16(4):E123.
  13. Laratta JL, Shillingford JN, Lombardi JM, et al. Accuracy of S2 alar-iliac screw placement under robotic guidance. Spine Deformity. 2018;6(2):130–6.
  14. Smith JS, Shaffrey CI, Ames CP, Lenke LG. Treatment of adult thoracolumbar spinal deformity: Past, present, and future. Journal of Neurosurgery: Spine. 2019;30(5):551–67.
  15. Kochanski RB, Lombardi JM, Laratta JL, et al. Image-guided navigation and robotics in spine surgery. Neurosurgery. 2019;84(6):1179–89.
  16. Sayari AJ, Pardo C, Basques BA, Colman MW. Review of robotic-assisted surgery: What the future looks like through a spine oncology lens. Annals of Translational Medicine. 2019;7(10):224.


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