Table 2. Impact of IG and robotics on operative radiation exposure.
| Study author, year | Study design | Freehand fluoroscopy | IG/RA | Key findings | |||
|---|---|---|---|---|---|---|---|
| Radiation to patient (Mrem) | Radiation to surgeon (Mrem) | Radiation to patient (Mrem) | Radiation to surgeon (Mrem) | ||||
| Smith, 2008 (37) | 48 PS placed in 4 cadavers throughout the lumbosacral spine. Two cadavers instrumented with freehand PS technique and two with Iso-C intraoperative CT with Medtronic StealthStation navigation | N/A | Torso 4.33; thyroid 0.33; Finger 0 | N/A | Torso 0.33; thyroid 0.66; Finger 0 | Similar PS accuracy between both techniques, navigation decreases exposure to the surgeon at the level of the torso. The surgeon left room during the use of CT, however, was still exposed to fluoroscopy radiation during localization | |
| Kantelhardt, 2011 (20) | Patients undergoing PS placement for spinal fusion regardless of indication (but including deformity) were retrospectively compared and stratified into either a robotic-assisted cohort (Mazor SpineAssist, open or percutaneous) versus a conventional freehand cohort. Radiation exposure measured by duration of X-ray exposure (seconds) | 77 seconds* | N/A | 27 seconds* | N/A | Patients in the IG cohort had a shorter duration of exposure to intraoperative X-ray, however, total dose of radiation exposure to patient or surgeon was not quantified. Pre- and/or post-operative CT scan radiation is not accounted for | |
| Roser, 2013 (22) | 3-arm prospective randomized controlled trial comparing PS placement by freehand, IG, and robotic (Mazor SpineAssist) techniques. Variety of operative indications including fracture, infection, instability, and deformity | 18.9 mGy | N/A | IG 4.04 mGy; R 11.0 mGy | N/A | No statistical analysis was performed. Authors hypothesize that the R cohort required more radiation exposure than IG due to the fact that there is a learning curve to R, whereas IG is more established | |
| Tabaraee, 2013 (38) | 160 PS placed in 8 cadavers throughout the thoracic and lumbar spine, 80 placed using O-arm with navigation and 80 placed using freehand technique with C-arm. No cadavers had deformity | 6.75–1,991.75 | 1.75–60.75 | 147–5,656.75 | 0 | No statistical difference in breach rates between freehand and IG cohorts. Initial setup time higher in IG group, however, total procedure length was not statistically different | |
| Villard, 2014 (39) | Prospective randomized study of 21 patients undergoing posterior spinal fusion, 10 navigated cases (Siemens Arcadis Orbic 3D fluoroscopy with BrainLab VectorVision navigation) and 11 freehand PS patients with fluoroscopy | 888 cGy × cm2* | Eye 9.1; thorax 24.9; Forearm 9.8 | 1884 cGy×cm2* | Eye 1.8; thorax 2.5; Forearm 1.5 | Statistically higher radiation exposure to surgeon in freehand cohort versus navigated. Each cohort had an average of 1.2 TLIF cages placed, which was all done without navigation and with fluoroscopy. In navigated cohort, surgeons left OR when 3D fluoroscopy was being performed | |
| Costa, 2016 (40) | Radiation exposure data for 107 patient who underwent spine surgery (unclear indication) using O-arm system with Medtronic StealthStation IG was retrospectively reviewed | N/A | N/A | 515 | 0 | Mean of 2.02 O-arm scans per patient, most often initial navigation scan and a final scan to confirm hardware position. Authors hypothesize that any increase in radiation dose to patient is offset by reducing need for postoperative CT and potential reoperations | |
| Mendelsohn, 2016 (41) | 146 patients undergoing spinal instrumentation were split into two equal size groups consisting of O-arm with IG versus freehand PS placement with fluoroscopy. Retrospective analysis performed to quantify radiation exposure | N/A | N/A | 606 | 69.7 | Navigation increased radiation exposure to patient and decreases exposure to surgeon, when compared with prior radiation exposure in freehand pedicle cohorts reported in the literature. Lumbar followed by thoracic procedures, and degenerative followed by deformity cases are associated with the most radiation exposure to surgeons | |
| Lonjon, 2016 (25) | Patients with lumbar stenosis, degenerative disc disease, or spondylolisthesis (unclear if patients had concomitant deformity) were prospectively assigned to a robotic cohort (ROSA, Medtech) or a freehand cohort | 821 cGy × cm2* | N/A | 406 cGy × cm2* | N/A | Statistically higher radiation exposure in robotic cohort. Duration of fluoroscopy was also higher at 1.23 min compared to 0.40 minutes in robotic and freehand cohorts, respectively | |
| Le, 2018 (26) | Patients undergoing lumbar spine instrumentation were retrospectively reviewed and a matched-cohort of patients undergoing robotic surgery (TiRobot, Tinavi) were compared to a freehand cohort | 77.5 seconds* | 7.57 | 142.8 seconds* | 3.27 | Measured radiation exposure to surgeon using a digital dosimeter at the level of the surgeon's chest outside of a lead apron. Exposure to patients was obtained from C-arm and represented as duration of C-arm use | |
| Vaishnav, 2020 (42) | Time-demand and radiation exposure of intra-operative 3-dimensional navigation (75 patients) for MI-TLIF were compared to that of 2D fluoroscopy (94 patients). |
144 seconds, 63.1 mGy | 144 seconds, 63.1mGy | 26 seconds, 44.6mGy | 17 seconds, 28.3 mGy | Compared to patients using conventional fluoroscopy for MI-TLIF, patients using navigation had the significant advantage in terms of shorter operative times, reduced fluoroscopy time and lower total radiation exposure, resulting in a 29% reduction in radiation dose to patients and a 55% reduction in radiation dose to the operating surgeon | |
*, all radiation measurements were originally reported in or were converted to millirem (Mrem), unless otherwise noted. PS, pedicle screw; IG, image guidance; RA, robotic-assistance.