34th Annual Scientific Meeting proceedings

Objectives:

To optimize clinical outcomes following Open Reduction and Internal fixation (ORIF) of SacroIliac Luxation/Fractures (SIL/Fs), Minimally Invasive Osteosynthesis (MIO) techniques have been devised. Radiation exposure and suboptimal sacral screw alignment prompted the development of a SacroIliac Luxation Instrumentation System and Minimally Invasive Lucent Aiming Device (SILIS-MILAD). Despite improvement in sacral screw placement, limitations included lengthy spinal and mechanical arms positional adjustments during manual reduction and fixation. This study describes MILAD assisted tele-robotic surgery for MIO of SIL/Fs via a remotely controlled dual robotic system. We hypothesize that tele-robotic surgery improves sacral screw alignment accuracy and repeatability compared to previous techniques.

Methods:

Right SIL/Fs were created in eight dogs that died naturally. Using two remotely controlled robotic arms featuring function-specific custom end-effectors, sacroiliac reduction and lag screw fixation were performed under fluoroscopic guidance. Fragment reduction and sacral MILAD alignment were monitored on computer screens four meters away from the X-ray source, while spinal alignment was maintained using a computer-controlled 6-axis Stewart platform. Manual iliosacral drilling and sacral screw placement were performed without fluoroscopy. Mean craniocaudal and dorsoventral screw angles (CCA and DVA [dorsal and transverse planes, respectively]) were measured on postoperative CT MPRs and compared to historical data.

Results:

Mean (±SD) CCA (0.4°±0.7°) and DVA (0.5°±0.8°) compare favorably to published ORIF (7.4°± 4.9° and 8.5°± 5.3°) and SILIS-MILAD (1.6°±1.1° and 1.20°±0.6°) data.

Conclusions:

This first study demonstrates that tele-robotic surgery is an accurate, consistent alternative to current SIL/Fs repair techniques. With ~90’ to ~11’ procedure times, this novel technique appears reasonable and promising.