CT-based morphometry and Mimics-guided virtual implantation of a facet-fusion-integrated posterior cervical semi-open-door system: an anatomical feasibility study

The management of multilevel cervical spondylosis with concomitant foraminal stenosis and instability remains challenging. Anterior-only, posterior-only, and circumferential procedures each present disadvantages regarding decompression adequacy, implant burden, and complication risk. We developed an integrated posterior system combining facet joint fusion and semi-open-door laminoplasty to enable decompression and stabilization through a single approach. Thirty cervical CT scans from healthy adults (C2-C7) were reconstructed in Mimics. Key morphometric parameters relevant to device design were assessed, including lateral mass height and facet dimensions, minimum lamina height, lamina safety length, interfacet gap height, facet inclination, and spinous process screw height. A concept construct comprising a lateral mass plate, interfacet fusion cage, and laminoplasty plate was dimensioned from these data and virtually implanted to evaluate anatomical compatibility. Bilateral and sex-related differences were analyzed (two-tailed α = 0.05) with prespecified assumptions for parametric testing and multiple-comparison control. Key morphometric parameters (e.g., lateral mass height: 11.5–13.3 mm; lamina safety length: 25.3–28.6 mm) supported the dimensional design of the system components. Statistical analysis showed no significant differences related to sex or side (all p > 0.05). Crucially, Mimics-guided virtual implantation demonstrated successful positioning of all components without cortical breach, validating the anatomical compatibility of the construct. CT-based morphometry and Mimics-guided virtual implantation demonstrate that the proposed facet-fusion-integrated posterior cervical semi–open-door system is anatomically feasible and dimensionally compatible with subaxial cervical anatomy. However, as this study is limited to imaging data and virtual simulation without biomechanical or clinical validation, the system should currently be regarded as a proof-of-concept design rather than a clinically established technique.