Do Multilevel Posterior Cervical Fusions Extended to T1 Reduce Revision Surgery Risk?

Gregory D. Schroeder, MD, Peter Whang, MD, FACS and Vincent Traynelis, MD discuss extending posterior multilevel cervical fusions to T1.

In the management of degenerative conditions of the cervical spine, multilevel posterior cervical fusions extended to T1 are linked to a lower revision rate compared to fusions terminating at C7, according to findings from a retrospective cohort analysis in the December 1 issue of Spine.
cervical multilevel anterior posterior postoperative xray image“The findings of this study suggest that terminating a multilevel posterior cervical decompression and fusion at C7 more than doubles the revision rate compared to similar patients who had the fusion extended to T1,” said lead author Gregory D. Schroeder, MD, who is a spine surgeon at The Rothman Institute at Thomas Jefferson University in Philadelphia, PA.

While extending cervical fusions into the thoracic spine is common practice, it remains a topic of ongoing debate, commented Peter Whang, MD, FACS, Associate Professor of Orthopaedics and Rehabilitation at the Yale University School of Medicine in New Haven, CT.

“The spinal column is subjected to increased biomechnical forces at the junction between the mobile, lordotic cervical spine and the relatively fixed, kyphotic thoracic spine,” Dr. Whang said. “The thought is that by extending the fusion past the cervicothoracic junction, the construct may be more stable and less prone to failure, which is what the study findings suggest,” Dr. Whang said.

Retrospective Cohort Analysis
Dr. Schroeder and colleagues analyzed outcomes from 219 patients who underwent a three or more level posterior cervical decompression and fusion and were followed for at least 1 year. The most common diagnosis was myelopathy (>80%); none of the patients underwent surgery for tumor, trauma, or infection. 

Revision Rate Was Lowest for Fusions Terminating at T1
The overall revision rate in this cohort was 27.8% (61/219 patients) at an average follow-up of 49.8 months. Revision rates varied significantly by caudal level of the fusion, with rates of 35% for those terminating at C7, 18% at T1, and 40% at T2-T4 (P=0.008).

Multivariate linear regression modeling indicated that the revision rate was 2.29 times higher among patients whose fusions terminated at C7 than among those whose construct terminated at T1 (P=0.02). Revision rates were not significantly different for fusions stopping at T1 versus T2-T4 (odds ratio, 2.16; P=0.12).

Dr. Schroeder said that he routinely extends multilevel posterior cervical fusions to T1. However, he noted that this study focused on degenerative conditions, and that “extrapolating this data to patients with fractures is challenging. When I am treating trauma patients, I only fuse the levels that need to be fused to address the fracture.”

“This study should significantly alter spine practice,” Dr. Schroeder told SpineUniverse. “Many surgeons stop long posterior cervical fusions at C7, but given this data, I would hope that they will consider extending the fusion to T1.”

“This study has significant clinical implications,” commented Vincent Traynelis, MD, a neurosurgeon at Rush University Medical Center in Chicago, IL. “For almost all cases, there is strong evidence that the fusion should be extended to T1, and this should be strongly considered in all cases. The loss of motion is minimal, and the chance that further surgery will not be necessary high.

Weighing the Risks and Benefits
“This study provides further support for the routine practice of extending cervical fusions into the thoracic spine,” Dr. Whang told SpineUniverse. He noted that surgeons must weigh the risks and benefits of this strategy for each patient as this involves a more lengthy procedure, increased cost, and potentially a greater risk of complications.

“What was most striking about this paper is that the revision rate was 27.8% at an average follow-up of approximately 4 years, which is higher than I expected,” Dr. Whang noted.

Dr. Whang added that the study findings are somewhat limited by its retrospective, single-site design. In addition, fusions stopped at T2-T4 were performed in only a relatively small number of patients (n=30), making it difficult to draw conclusions regarding fusions terminated caudal to T1.

“It is not clear why the fusions extended to T2 to T4 were problematic, but it is likely these patients had significant upper thoracic pathology, and that could account for the symptoms,” said Dr. Traynelis, who also is a member of the SpineUniverse Editorial Board.

“Certainly, additional research is warranted particularly with the growing interest in aggressive surgical procedures to optimize the sagittal vertical alignment in the cervical region,” Dr. Traynelis concluded.

Updated on: 03/22/17
Continue Reading
Mount Sinai Offers Onsite 3D Printing Services for Spine Clinicians and Researchers
SHOW MAIN MENU
SHOW SUB MENU
Cancel
Delete

Get new patient cases delivered to your inbox

Sign up for our healthcare professional eNewsletter, SpineMonitor.
Sign Up!