Clinical and Radiological Outcomes of Posterior Cervical Fusion Supplemented With Interfacet Spacers

This is a prospective study to assess fusion rates and cervical sagittal parameters following posterior cervical arthrodesis procedures supplemented with CIS. Data will be collected from medical records for up to 730 days after surgery. Data to be collected will be demographic, preoperative clinical information, surgical details, and radiographic information. Patients will also undergo a non-standard of care CT scan 2 years after surgery.

Study Overview

• Status: Recruiting
• Conditions: Cervical Fusion
• Intervention / Treatment: Device: Cervical Interfacet Spacers

Detailed Description

Background and Rationale

Posterior cervical fusion surgeries are performed for degenerative cervical conditions, cervical deformity, cervical tumors, and cervical trauma. They are preferred over an anterior approach when the pathology is located posterior to the spinal cord or when multiple levels must be addressed. Degenerative cervical spondylosis contributes to loss of disc height, facet arthropathy and hypertrophy, and retrolisthesis of the vertebral bodies, all of which can lead to foraminal stenosis, or narrowing around the exiting nerve roots. This is often accompanied by loss of cervical lordosis. During a posterior fusion operation, the restoration of cervical lordosis can worsen this foraminal stenosis and lead to iatrogenic radiculopathy with and estimated incidence between 2.4-50%. Cadaveric studies have shown the insertion of interfacet spacers in the cervical spine increase foraminal height, and serve to indirectly decompress the exiting nerve roots. Another common complication of cervical spine surgery is C5 palsy, which has been reported in 4.6% of patient undergoing posterior cervical spine decompressive procedures, including decompression and fusion. Patients suffering from iatrogenic C5 palsy have significantly increased recovery times, and often require additional services such as imaging studies (CT, MRI) and increased need for physical and occupational therapy, thus increasing costs. Given the ability to decompress the neuroforamen with interfacet spacers, they could potentially be an effective technique for reducing the incidence of C5 palsy.

The use of cervical interfacet spacers (CIS; CORNERSTONE Facet MicroGrafts, Medtronic, Minneapolis, MN) is a relatively novel technique shown to be useful for posterior fusion to address symptomatic pseudoarthrosis (fusion failure) after anterior cervical arthrodesis. CIS have a relatively large osteoconductive surface area and are placed under tension in the interfacet space, which together favorably influence bony fusion. Current techniques for posterior cervical fusion rely on graft placement using bone extenders placed in the posterolateral space, which is not under a compressive load. Wolfe's law dictates that certain amounts of loading of bone grafts is required to achieve bony fusion. Therefore, the use of CIS could potentially increase fusion rates after posterior cervical arthrodesis procedures and reduce or eliminate the need for use of bone graft extenders. Reassuringly, radiologic studies have shown that despite the increase in foraminal height, the use of CIS does not lead to loss of cervical lordosis.

Study Objective

To date, there have been no prospective studies examining the use of cervical interfacet spacers. The investigators propose to undertake a prospective study to assess fusion rates and cervical sagittal parameters following posterior cervical arthrodesis procedures supplemented with CIS.

Primary Outcome Measures The primary outcome measures will include (i) the rate of cervical fusion measured on post-operative radiographs and CT scans performed at 2-years and (ii) cervical sagittal alignment parameters as measured on post-operative radiographs.

Secondary Outcome Measures The secondary outcome measures will include post-operative patient reported outcomes including NRS, NDI, and SF-36 RAND. As well, all neurological adverse events will be prospectively collected.

• Study Type: Observational
• Enrollment (Anticipated): 45

Contacts and Locations

• Study Contact: Name: Shukri A Ahmed, MPH; Phone Number: 614-814-7007; Email: shukri.ahmed@osumc.edu
• Study Contact Backup: Name: Allie Garvin, BS; Phone Number: 614-688-8304; Email: allison.garvin@osumc.edu

Study Locations

• United States
  • Ohio
    • Columbus, Ohio, United States, 43210
      • Recruiting
      • The Ohio State University Wexner Medical Center
      • Principal Investigator: Andrew Grossbach, MD
      • Contact: Allie Garvin, BS; Phone Number: 614-688-8304; Email: allison.garvin@osumc.edu
      • Contact: Shukri A Ahmed, MPH; Email: shukri.ahmed@osumc.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 16 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Patients undergoing posterior cervical arthrodesis procedures for spondylosis supplemented with CIS involving three or more segmental levels in the subaxial cervicothoracic spine (between C2-upper thoracic)

Description

Inclusion Criteria:

• ≥ 18 years old
• Symptomatic multi-level degenerative spondylosis necessitating posterior cervical arthrodesis in the subaxial cervicothoracic spine (between C2-upper thoracic).
• Surgery performed within the Department of Neurological Surgery at The Ohio State University Wexner Medical Center (OSUWMC)

Exclusion Criteria:

• Traumatic injury
• Co-morbidity requiring medication use that may interfere with bone or soft tissue healing (i.e., high dose oral or parenteral glucocorticoids, immunosuppressive agents, methotrexate) - at discretion of investigator
• Severe co-morbidities (e.g., heart, respiratory, or renal disease)
• Recent (<3 yrs) or co-incident spinal tumor or infection
• Concurrent involvement in another investigational drug or device study that could confound study data
• History of substance abuse (recreational drugs, prescription drugs or alcohol) that could interfere with protocol assessments and/or with the subject's ability to complete the protocol required follow-up
• Subjects who are pregnant or plan to become pregnant in the next 24 months
• Prisoner

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Only
• Time Perspectives: Prospective

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

Arm 1; Patients undergoing posterior cervical arthrodesis procedures for spondylosis supplemented with CIS involving three or more segmental levels in the subaxial cervicothoracic spine (between C2-upper thoracic)

Device: Cervical Interfacet Spacers; The use of Cervical Interfacet Spacers is a relatively novel technique shown to be useful for posterior fusion to address symptomatic pseudoarthrosis (fusion failure) after anterior cervical arthrodesis [2]. CIS have a relatively large osteoconductive surface area and are placed under tension in the interfacet space, which together favorably influence bony fusion [2].; Other Names: (CIS; CORNERSTONE Facet MicroGrafts, Medtronic, Minneapolis, MN)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cervical Fusion	Cervical Fusion Measured on Post-Operative Radiographs and CT scans	2-Years
Cervical Sagittal Alignment Parameters	Cervical Sagittal Alignment Parameters measured on post-operative radiographs	2-Years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
NRS	Numerical Rating Score for Pain from 0-10 where lower values represent a better outcome	2-Years
NDI	Neck Disability Index from 0-100% where lower values represent a better outcome	2-Years
SF-36 RAND	Quality of Life Measures from 0-100 where higher values represent a better outcome	2-Years
Neurological Adverse Events	Adverse Events	2-Years

Collaborators and Investigators

• Sponsor: Ohio State University
• Collaborators: Medtronic
• Investigators: Principal Investigator: Andrew Grossbach, MD, The Ohio State University Wexner Medical Center

Publications and helpful links

General Publications

• Tan LA, Gerard CS, Anderson PA, Traynelis VC. Effect of machined interfacet allograft spacers on cervical foraminal height and area. J Neurosurg Spine. 2014 Feb;20(2):178-82. doi: 10.3171/2013.11.SPINE131. Epub 2013 Dec 13. Erratum In: J Neurosurg Spine. 2014 Jun;20(6):772.
• Kasliwal MK, Corley JA, Traynelis VC. Posterior Cervical Fusion Using Cervical Interfacet Spacers in Patients With Symptomatic Cervical Pseudarthrosis. Neurosurgery. 2016 May;78(5):661-8. doi: 10.1227/NEU.0000000000001087.
• Mummaneni PV, Meyer SA, Wu JC. Biological approaches to spinal instrumentation and fusion in spinal deformity surgery. Clin Neurosurg. 2011;58:110-6. doi: 10.1227/neu.0b013e3182270009. No abstract available.
• Tan LA, Straus DC, Traynelis VC. Cervical interfacet spacers and maintenance of cervical lordosis. J Neurosurg Spine. 2015 May;22(5):466-9. doi: 10.3171/2014.10.SPINE14192. Epub 2015 Feb 13.
• Fogel GR, Toohey JS, Neidre A, Brantigan JW. Fusion assessment of posterior lumbar interbody fusion using radiolucent cages: X-ray films and helical computed tomography scans compared with surgical exploration of fusion. Spine J. 2008 Jul-Aug;8(4):570-7. doi: 10.1016/j.spinee.2007.03.013. Epub 2007 May 29.
• Turel MK, Kerolus MG, Traynelis VC. Machined cervical interfacet allograft spacers for the management of atlantoaxial instability. J Craniovertebr Junction Spine. 2017 Oct-Dec;8(4):332-337. doi: 10.4103/jcvjs.JCVJS_87_17.

Study record dates

Study Major Dates

• Study Start (Actual): September 1, 2019
• Primary Completion (Anticipated): August 1, 2025
• Study Completion (Anticipated): August 1, 2025

Study Registration Dates

• First Submitted: July 23, 2019
• First Submitted That Met QC Criteria: July 30, 2019
• First Posted (Actual): August 1, 2019

Study Record Updates

• Last Update Posted (Actual): May 12, 2023
• Last Update Submitted That Met QC Criteria: May 10, 2023
• Last Verified: May 1, 2023

More Information

Terms related to this study

• Other Study ID Numbers: 2019H0015

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: No