Abstract
Background Posterior facetectomy or lateral mass resection is often used during cervical dumbbell
tumor resection, jeopardizing the stability of cervical spine. The space after resection
of one or more lateral masses, if left unfilled might hamper bone fusion and structural
support.
Purpose There were the aims to obtain the relevant morphometry of the lateral mass of the
subaxial cervical spine (C3–C7) and to design a lateral mass prosthesis for the posterior
reconstruction of the cervical spine.
Methods The computed tomography (CT) scans of healthy volunteers were obtained. RadiAnt DICOM
Viewer software (Version 2020.1, Medixant, Poland) was used to measure the parameters
of lateral mass, such as height, anteroposterior dimension (APD), mediolateral dimension
(MLD), and facet joint angle. According to the parameters, a series of cervical lateral
mass prostheses were designed. Cadaver experiment was conducted to demonstrate its
feasibility.
Results Twenty-three volunteers with an average age of 30.1 ± 7.1 years were enrolled in
this study. The height of the lateral mass was 14.1 mm on average. The facet joint
angle, APD, and MLD of the lateral mass averaged 40.1 degrees, 11.2 mm, and 12.2 mm,
respectively. With these key data, a lateral mass prosthesis consisting of a column
and a posterior fixation plate was designed. The column has a 4.0-mm radius, 41-degree
surface angle, and adjustable height of 13, 15, or 17 mm. In the cadaver experiment,
the column could function as a supporting structure between adjacent facets, and it
would not violate the exiting nerve root or the vertebral artery.
Conclusion This study provided a detailed morphology of the lateral mass of the subaxial cervical
spine. A series of subaxial cervical lateral mass prostheses were designed awaiting
further clinical application.
Keywords
cervical vertebral tumor - lateral mass prosthesis - lateral mass morphology - posterior
reconstruction - cervical spine
