Spine Research With Roentgen Stereophotogrammetric Analysis (SpineRSA)

February 18, 2013 updated by: William Oxner, Nova Scotia Health Authority

A Consecutive Case Series of One-Level Lumbar Fusions With Pedicle Screw Instrumentation and the Trabecular Metal™ Intervertebral Cage Using Roentgen Stereophotogrammetric Analysis (RSA)

The purpose of this study is to gather information on the effectiveness of a new spine implant for patients who require spinal fusion surgery. Based on this information, we hope to create a standard of good performance, or benchmark, against which future studies on this spine implant can be compared. By creating this benchmark we hope to improve care for patients who require spinal fusion surgery.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Device: Trabecular Metal Intervertebral Cage with RSA beads

Detailed Description

For patients in whom a spinal fusion is indicated, the posterior lumbar interbody fusion (PLIF) may be recommended to restore stability to the affected spinal segment1. Pioneered by a Dr.Cloward in the 1940s to treat painful intervertebral discs damaged by degeneration, PLIF involves removal of the entire nuclear portion of the disc and subsequent replacement with multiple blocks of transplanted bone. The purpose of the fusion is to eliminate or reduce the amount of the motion at the affected site, and, therefore, the source of pain.

Four major intervertebral cages have been approved by the Food and Drug Administration (FDA) for use in humans: the Brantigan Interbody fusion Cage, the Ray Threaded Fusion Cage, the Bagby and Kuslich cage, and, most recently, the Trabecular Metal™ Cage. Comprised of 98 percent tantalum and 2 percent vitreous carbon, Trabecular Metal™ has the highest coefficient of friction of any implant material on the market, allowing for optimal initial implant-bone fit. Furthermore, the unique porous structure of Trabecular Metal™ provides significantly more space for tissue ingrowth to occur, facilitating a more cohesive implant-bone interface as well as long-term stability of the implant.

Long-term follow up data on the efficacy of the Brantigan Interbody fusion cage, Ray Threaded Fusion cage, and Bagby and Kuslich cages are limited, with the most rigorous studies (i.e. controlled prospective studies) typically providing outcomes approximately 2 years post-surgery. Overall, these studies show that, while existing intervertebral cages have made significant advances in terms of addressing the disadvantages associated with traditional bone grafting/fixation techniques, problems continue to persist. Through comprehensive and accurate clinical evaluation of the Trabecular Metal™ intervertebral cage, the Research Team hopes to document advances in the PLIF technique, thereby informing current research as well as clinical practice.

The primary goal of the proposed research is to gather data on the clinical efficacy of the Trabecular Metal™ Posterior Lumbar Interbody Fusion (PLIF) cage with pedicle screw instrumentation for the treatment of one-level lumbar spine fusions. Based on this pilot data, we hope to establish a level of acceptable clinical performance for the Trabecular Metal™ cage, a benchmark against which subsequent investigations can be compared.

Direct surgical exploration is considered the most reliable method for accurately determining fusion success, both from a structural and functional perspective, following spinal fusion surgery. Unfortunately, this method is highly invasive, costly and seldom used. Furthermore, surgical exploration does not provide any longitudinal information as to the stability of the implant, including the monitoring of any occurrence of migration.

In contrast, Roentgen Stereophotogrammetric Analysis(RSA)can detect the presence or absence of mobility between intervertebral segments (i.e. functional stability of the fusion) with a high degree of accuracy. RSA is a radiographic technique that uses small tantalum balls implanted into the patient's bone to measure micromotion (<1 mm) at the bone - implant interface, something which is not possible to do reliably using regular x-ray techniques. RSA provides a method for detecting inferior implant designs or cement formulations using only a small number of patients before release of these products into large clinical trials.

RSA has been in use for several decades,and its safety is well documented.A computerized, digital RSA system has recently been installed and calibrated at our center. Its measurement capabilities have been rigorously validated, and it is currently being used to assess a new knee implant design. Expansion of the system to include spine RSA can be easily accomplished.

Study Type

Interventional

Enrollment (Actual)

Phase

Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

Canada
- Nova Scotia
  - Halifax, Nova Scotia, Canada, B3H-3A7
    - Capital District Health Authority, QEII Health Sciences Centre,& Dalhousie University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

16 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Genders Eligible for Study

All

Description

Inclusion Criteria:

Patients must be at least 20 years of age
Clinical and radiologic history of spondylolisthesis (no greater than grade 1)
Spinal stenosis for which conservative treatment has failed
Degenerative disc disease, characterized by one or more of the following:
- instability (defined as angular motion > 5° and/or translation > 4mm, based on Flex/Ext radiographs)
- osteophyte formation
- decreased disc height
- thickening of ligamentous tissue
- disc degeneration or herniation
- facet joint degeneration

Exclusion Criteria:

Fusion at more than one level
Non-fusion surgery at the involved level
Previously diagnosed with osteopenia, osteoporosis, or osteomalacia to a degree that spinal instrumentation would be contraindicated
Patients with a highly-communicable disease, inflammatory or auto-immune based joint disease
Those with a history of endocrine or metabolic disorders known to affect osteogenesis (e.g. Paget's disease, renal osteodystrophy, Ehlers-Danios syndrome or osteogenesis imperfecta)
Patients with a documented titanium or tantalum alloy allergy or intolerance
Patients currently receiving active treatment for cancer or treatment with steroids such as cortisone
Patients with significant medical history that, in the Investigator's opinion, would not make them a good study candidate

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Primary Purpose: Treatment
Allocation: N/A
Interventional Model: Single Group Assignment
Masking: None (Open Label)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Spinal fusion and the rate of fusion and maintenance of spinal alignment will be assessed Time Frame: 6 weeks, 3, 6, 12, and 24months.	6 weeks, 3, 6, 12, and 24months.

Secondary Outcome Measures

Outcome Measure	Time Frame
Subjective outcome questionnaires will be used to characterize the patient sample used for the study to allow for comparisons to other treatments for this condition in the future. Time Frame: 3, 6, 12, 24 months	3, 6, 12, 24 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Nova Scotia Health Authority

Collaborators

Zimmer Biomet

Investigators

Principal Investigator: Dr. Wm Oxner, M.D., Capital District Health Authority, QEII Health Science Centre, & Dalhousie University, Halifax. Nova Scotia,Canada

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

July 1, 2007

Primary Completion (Actual)

June 1, 2012

Study Completion (Actual)