Robot-assistance in revision thoracolumbar fusion surgeries - Prospective study of 64 patients.

Background: Robot-assisted spine surgery is currently gaining popularity in thoracolumbar spine instrumentation because of enhanced precision and safety. Revision spine surgeries present unique challenges by virtue of abnormal anatomical bony landmarks, broken implants/bone cement in-situ and loose implant tracts, posing difficulties in re-implantation of screws. We evaluated the usefulness of Robot-assistance in Revision Spine Surgeries for varied pathologies. Methods: We prospectively analysed 64 consecutive patients undergoing Revision Thoracolumbar Spine Instrumented Fusion Surgeries over one-year. The causes of revision surgery were broken implants (20), adjacent segment disease (19), revision deformity surgeries (12), surgical site infection with implant loosing (8) and failed back syndrome secondary to cement augmentation (5). The O-arm time, cut to close time, radiation dose, robot time, time per screw, operative time, blood loss, screw accuracy, and intraoperative complications were noted. Results: Robot-assisted revision pedicle screw placement was successfully performed for 388 screws in 64 patients. The mean O-arm time was 10.3 ± 2.2 min, cut to close time was 157.9 ± 45.8 min, and radiation dose was 16.6 ± 3.7 mGy, robot time was 18.2 ± 3.7 min, time per screw was 3.1 ± 1.3 min, and blood loss was 538.8 ± 156.9 mL. No intraoperative complications were reported. Two out of 388 revised screws was misplaced without clinical implications. Conclusions: Robot-assisted revision thoracolumbar spine surgery offers alternate safe bony corridors for placement of screws in revision spine surgeries with loose/broken implants/bone cement with accuracy and safety. It demonstrated acceptable operative time, blood loss, and radiation exposure with high screw placement accuracy and no intraoperative complications.