A new minimally invasive cervical pedicle screw (CPS) fixation system using intra-operative computed tomography-guided navigation.

Background: Since its introduction, placement of cervical pedicle screws (CPS) has been considered a procedure with a very high-risk profile. Minimally invasive CPS placement was not even considered at all. However, as surgical techniques and image guided intra-operative navigation have been refined over the last decade, navigated CPS placement has become a standard procedure in well-established spine centers. Currently, the first off-the-shelf percutaneous CPS placement platforms are becoming available. The aim of this study is to assess feasibility and accuracy of an minimally invasive surgery (MIS) CPS fixation system in a pilot series.

Methods: Between January and July 2023, we treated a cohort of ten patients using a new cervical MIS platform. Forty pedicle screws were inserted percutaneously in the c-spine using intra-operative computed tomography (CT) guided navigation and retrospectively analysed for accuracy using a modified Gertzbein & Robbins (G&R) classification. Adverse events and other patient-related data were also documented.

Results: Ninety percent of all screws were placed accurately (80% on perfect trajectory, 10% showed minor perforations). Another 10% (four screws) caused pedicle wall breaches between 2 and 4 mm, but were not revised, since misplacement was not associated with neurological deficit or inferior biomechanics. One patient experienced neurological deterioration, but not associated with screw misplacement. The transverse foramen was breached twice, however not endangering the vertebral arteries.

Conclusions: In this pilot series MIS CPS placement yielded accurate placement rates comparable to open surgical approaches reported in the literature. Hence, MIS CPS placement appears to be a feasible and safe procedure in selected cases.