Does Interbody Height and Material Influence Radiographic Pseudarthrosis in ACDF? Insights from a Single-Institution Study

Wednesday, February 21, 2024

Presenting Author(s)

Hani Chanbour, MD

Spine fellow
Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, TN
Nashville, TN, US

Co-Author(s)

AA

Amir Abtahi, MD

orthopedic surgeon
Department of Orthopedic Surgery, Vanderbilt University Medi, United States
Andrew J. croft, MD

resident
Vanderbilt University Medical Center, United States
Raymond Gardocki, MD

orthopedic surgeon
Department of Orthopedic Surgery, Vanderbilt University Medi
Franklin, Tennessee, United States
bH

brian Hou, BS

Medical student
Vanderbilt University School of Medicine, United States
David Liles, MD

Resident
Vanderbilt University Medical Center
Nashville, TN, US
Jl

Julian lugo-pico, MD

orthopedic surgeon
Vanderbilt University Medical Center, United States
BS

Byron Stephens, MD

orthopedic surgeon
Vanderbilt University School of Medicine, United States
Iyan Younus, MD

resident
Vanderbilt University Medical Center
Nashville, TN, US
Omar Zakieh, MD

Spine fellow
Vanderbilt University Medical Center
Scott L. Zuckerman, MD, MPH (he/him/his)

Assistant Professor of Neurological Surgery
Vanderbilt University Medical Center
Nashville, Tennessee, United States

Disclosure(s):

Hani Chanbour, MD: No financial relationships to disclose

David Liles, MD: No financial relationships to disclose

Omar Zakieh, MD: No financial relationships to disclose

Introduction: The success of an anterior cervical discectomy and fusion (ACDF) depends on obtaining solid bony fusion to achieve stability and restore disc height. While various interbody graft options exist, the impact of graft height and material on fusion rate remains an area of ongoing investigation. In patients undergoing 1-3 level ACDF, we sought to determine the impact of graft height and material on radiographic pseudarthrosis, pseudarthrosis requiring reoperation, and patient-reported outcome measures (PROMs).

Methods: Patients who underwent 1-3 level primary ACDF between 2010-2021 were studied. Graft height and material (structural allograft vs. prosthetics) were the primary independent variables. The primary outcome was pseudarthrosis, defined as interspinous motion >2mm on flexion-extension lateral x-rays at 1-year postoperatively. PROMs included Numeric Rating Scale-Arm/Neck and Neck Disability Index. Multivariable logistic regression was performed. A sub-analysis was conducted for prosthetic sub-material (PEEK vs. titanium).

Results: 153 patients were included (mean age 51.8 ± 11.0 years; 42.5% male). Most patients had 1-2 levels operated on and 33.3% had structural allograft as the interbody implant. Prosthetic implants were used in 66.7% of patients, with PEEK being the most common (80.4%). At 1-year postoperatively, 29.4% of patients developed pseudarthrosis, and 6.7% underwent reoperation. There were no significant differences in graft height, material, or prosthetic sub-material between patients with and without pseudarthrosis. Multivariable logistic regression also did not show any significant associations between graft height, material, or prosthetic sub-material with pseudarthrosis, reoperation, or PROMs (all p>0.05).

Conclusion : Graft height and material did not significantly affect pseudarthrosis, reoperation, or PROMs in patients undergoing primary ACDF. While graft height and composition alone may not be critical determinants for fusion success in ACDF, Other factors such as patient-specific characteristics and surgical technique may contribute to the risk of pseudarthrosis and should be explored in future studies.