Are Variable Screw Angle Change and Screw-to-Vertebral Body Ratio Associated With Radiographic Subsidence Following Anterior Cervical Discectomy and Fusion?
Global Spine J
; : 21925682241252088, 2024 May 05.
Article
in En
| MEDLINE
| ID: mdl-38706298
ABSTRACT
STUDY DESIGN:
Retrospective Cohort.OBJECTIVE:
This study aims to assess the easily measurable radiographic landmarks of screw-to-vertebral body ratio and changes in screw angle to identify if they are associated with early subsidence following an Anterior cervical discectomy and fusion (ACDF).METHODS:
A retrospective cohort study was conducted on patients undergoing 1-3 level ACDF with allograft or PEEK cages. Preoperative, immediate postoperative, and 6-month postoperative radiographs were analyzed to measure intradiscal height (or distance between 2 vertebral bodies) as an anterior vertebral distance (AVD), middle (MVD), and posterior (PVD), screw angle, screw-to-vertebral body length ratio, and interscrew distance. Multivariate stepwise regression analyses were performed.RESULTS:
92 patients were included (42 single-level, 32 two-level, and 18 3-level ACDFs). In single-level ACDFs, a decrease in the caudal screw angle was associated with a decrease in AVD (=.001) and MVD (P = .03). A decrease in the PVD was associated with a decrease in segmental lordosis (P < .001). For two-level ACDFs, a higher caudal screw-to-body ratio was associated with a lower MVD (P = .01).CONCLUSION:
Six months following an ACDF for degenerative pathology, a decrease in the caudal screw angle was associated with an increase in radiographic subsidence at the antero-medial aspect of the disc space albeit largely subclinical. This suggests that the caudal screw angle change may serve as a reliable radiographic marker for early radiographic subsidence. Furthermore, a greater screw-to-vertebral body ratio may be protective against radiographic subsidence in two-level ACDF procedures.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
Global Spine J
Year:
2024
Document type:
Article
Affiliation country:
Estados Unidos