Longer Screws Decrease the Risk of Radiographic Pseudarthrosis Following Elective Anterior Cervical Discectomy and...

Area of Science:

• Spine surgery
• Orthopedic surgery
• Biomedical engineering

Background:

• Anterior cervical discectomy and fusion (ACDF) is a common procedure for cervical spine pathologies.
• Screw fixation is critical for achieving stability and fusion in ACDF.
• The optimal screw length for ACDF remains a subject of investigation.

Purpose of the Study:

• To evaluate the impact of screw length on radiographic pseudarthrosis after ACDF.
• To assess the relationship between screw length and pseudarthrosis requiring revision surgery.
• To determine the effect of screw length on patient-reported outcome measures (PROMs).

Main Methods:

• Retrospective cohort study of 406 patients undergoing ACDF from 2010-2021.
• Analysis of screw length, screw length as a percentage of vertebral body diameter (VB%), and screw placement (VB% < 75% vs. ≥ 75%).
• Multivariable logistic regression controlled for patient and surgical factors.

Main Results:

• Patients with any screw < 75% VB% had higher radiographic pseudarthrosis rates (39.6% vs. 22.1%, P < .001).
• Higher VB% (OR = .97) and all screws ≥ 75% VB% (OR = .51) significantly reduced pseudarthrosis odds.
• No significant differences were observed in reoperation rates or PROMs based on screw length parameters.

Conclusions:

• Utilizing longer screws that occupy ≥75% of the vertebral body diameter can protect against 1-year radiographic pseudarthrosis following ACDF.
• Maximizing screw length is an actionable surgical modification to potentially reduce the risk of pseudarthrosis.
• Screw length optimization is a controllable factor for improving ACDF outcomes.