Fixed-Angle Static Versus Variable-Angle Dynamic Plates for Multilevel Anterior Cervical Discectomy and Fusion

Area of Science:

• Spine surgery
• Orthopedic surgery
• Degenerative cervical spine disease

Background:

• Dynamic plates in multilevel ACDF theoretically improve fusion rates by allowing subsidence.
• Fixed-angle static plates may preserve cervical lordosis and construct height.
• Existing literature on static versus dynamic plates in ACDF shows variable outcomes.

Purpose of the Study:

• To compare the efficacy of fixed-angle static versus dynamic plates in multilevel ACDF.
• To evaluate the impact of plate type on maintaining cervical lordosis and construct height.
• To assess functional outcomes, nonunion rates, and complications associated with each plate type.

Main Methods:

• Retrospective cohort study of patients undergoing 2- or 3-level ACDF.
• Comparison of fixed-angle static plates versus dynamic plates used between April 2017 and July 2022.
• Radiographic assessment of fusion construct lordosis and height loss, with functional outcome measures including PROMIS PF and VAS scores.

Main Results:

• Fixed-angle static plates demonstrated significantly greater maintenance of fusion construct lordosis compared to dynamic plates.
• No significant differences were observed in fusion construct height loss, per-segment height loss, nonunion rates, or functional outcome scores (PROMIS PF, VAS neck/arm) between the groups.
• Complication rates were similar between the static and dynamic plate groups.

Conclusions:

• Fixed-angle static plates may be superior in maintaining cervical lordotic alignment following multilevel ACDF.
• Both static and dynamic plates offer comparable short-term functional outcomes, union rates, and complication profiles.
• Further long-term studies are warranted to confirm these findings.