MACHINE-VISION IMAGE-GUIDED SURGERY IN POSTERIOR SPINAL FUSION FOR SCOLIOSIS: LEARNING POINTS FROM 277 CASES OVER 5.5 YEARS

The advancement of machine-vision image-guided surgery (MvIGS) technology in recent years has transformed the paradigm of spinal surgery allowing surgeons real-time imaging with multiple planes of vision and without the use of intraoperative radiation.

Since Aug 2020, all posterior spinal fusions (PSF) for scoliosis at our institution have been done with MvIGS technology. Advantages and disadvantages, as well as complications are recorded.

At the time of writing, MvIGS had been used for 277 PSFs for scoliosis, in which a total of 4694 screws were navigated. In this series, no patient developed a medial pedicle wall breach, and none had an iatrogenic durotomy and CSF leak. MvIGS allowed the safe passage of in-out-in pedicle screws when the pedicles were assessed to be too narrow on intra-op CT. No patient had a MEP or SSEP drop from pedicle screw placement, or other neurological deficit. Intraoperative radiographs were utilised only for level confirmation, to check pedicle screw placement, and again after final tightening of the entire construct; an average of 10–12 C-arm images were taken at each surgery. A disadvantage of the MvIGS is that patients will need a pre-op spinal CT, albeit one of a slightly lower dose. The MvIGS can also have accuracy issues occasionally, requiring a repeat ‘flash’ or two (1–2 minutes each); these seem to occur most frequently at L3 or L4, on one occasion this resulted in a superior wall breach.

MvIGS technology has allowed pedicle screws to be passed more efficiently, accurately and with greater confidence in PSF for paediatric scoliosis. Operative time, blood loss and length of stay have decreased overall. Pre-op CT may be replaced by Bone MRI soon, further reducing the radiation exposure for patients.