Surgical Outcomes of Robotic-Guidance vs. Freehand Instrumentation: A Retrospective Review of 705 Adult Degenerative Spine Patients Operated in Minimally Invasive and Open Approaches

Presented at SMISS Annual Forum 2016
By Andrew Cannestra MD PhD
With Thomas Sweeney MD, Kees Poelstra MD, Samuel Schroerlucke MD,

Disclosures: Andrew Cannestra MD PhD B; Nuvasive, Mazor Robotics, RTI, Alliance Spine. F; RTI Thomas Sweeney MD B; Mazor., Kees Poelstra MD B; Mazor., Samuel Schroerlucke MD B; Mazor.,


Minimally invasive spinal fusion surgeries are becoming more common as hardware and computer guidance systems evolve. Yet MIS is still the exception rather than the norm with several barriers to adoption that focus on the learning curve, increased radiation exposure and contested clinical value to the patient. In recent years, robotic-guidance has become available for spinal surgeries, aiding surgeons in shortening the learning curve of MIS techniques and reducing the intraoperative exposure to harmful radiation. However, few data were presented on its impact on clinical outcomes, especially in the hands of experienced MIS surgeons. 


To assess the impact of robotic-guidance on clinical outcomes, especially in the hands of experienced MIS surgeons. 


Data were collected retrospectively from 4 surgeons for patients operated with robotic-guidance in a MIS approach (RGM), and compared with patients operated with fluoroscopic-guidance MIS (FGM) or open (FGO) approaches. All cases were instrumented fusions using either a minimally invasive technique with pedicle screws inserted in a percutaneous para-median approach, or a classic open approach through a median dissection. Logistic regression analysis was used to assess the odds ratio of complications and surgical revisions. 


Altogether, data from 705 patients were collected, 403 RGM patients, 224 FGM and 78 FGO. There were no significant differences in age, sex or BMI between arms or surgeons, except for 1 of the 4 groups in RGM that was significantly older by about 6 years. The complication rates were 4.0%, 5.4% and 12.8% for RGM, FGM and FGO respectively. The revision rate for RGM was 3.8% while for both FGO and FGM it was 7.7%. A logistic regression was performed and demonstrated that the odds ratio for surgical complications were 3.0 for FGM (p=0.014, 95% confidence interval (CI95) = 1.2-7.1) and 3.1 for FGO (p=0.009, CI95 = 1.3-7.3). The odds ratio for surgical revisions was 3.8 for FGM (p=0.006, CI95 = 1.5-10.0), and 1.9 for FGO but it was not statistically significant (small sample size). Surgeon, age, gender, BMI, or length of surgery, were non-significant parameters in the regression model. 


This retrospective analysis demonstrates that use of robotic guidance MIS can significantly reduce surgical complications and revision surgeries when compared to fluoro-guided MIS in the hands of experienced MIS surgeons.