MIS MiLIF Versus Open

A Multi-Center Study to Evaluate MiLIF(R) Versus Open Posterior Unilateral Lumbar Interbody Fusion (TLIF)

This study is being undertaken to compare the clinical outcomes of patients that have unilateral posterolateral lumbar interbody fusion using a traditional open approach versus the MiLIF procedure based on the MiCOR Precision Bone Allograft, specialized Atavi instrumentation, and minimally invasive visualization capabilities.

Study Overview

• Status: Completed
• Conditions: Chronic Low Back Pain; Leg Pain
• Intervention / Treatment: Device: The Atavi System

Detailed Description

This is a prospective, multi-center, non-randomized cohort design clinical study to evaluate the clinical outcomes of patients that have a minimally invasive lumbar interbody fusion (MiLIF) through the Atavi system compared to traditional unilateral open lumbar interbody fusion through a midline incision. the study will involve up to approximately 12 investigational sites and enroll up to 126 patients.

• Study Type: Observational
• Enrollment (Actual): 113

Contacts and Locations

Study Locations

• United States
  • California
    • La Jolla, California, United States, 92037
      • La Jolla Spine Institute
    • San Diego, California, United States, 92123
      • Sharp Rees-Stealy Medical Group
  • Florida
    • Port Charlotte, Florida, United States, 33948
      • Advanced Orthopedic Center
    • Sarasota, Florida, United States, 34232
      • Southeastern Spine Center
    • Sarasota, Florida, United States, 34233
      • Kennedy-White Orthopedic
  • Oregon
    • Portland, Oregon, United States, 97225
      • Oregon Brain & Spinal Institute
    • Salem, Oregon, United States, 97302
      • Williamette Neurosurgery
  • Texas
    • El Paso, Texas, United States, 97720-5001
      • William Beaumont Army Medical Center
  • Virginia
    • Portsmouth, Virginia, United States, 23708
      • Naval Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 75 years (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Patients with chronic low back and/or leg pain who are candiates for elective lumbar interbody fusion through a postierior unilateral approach, that present to either group of surgeons, will be screened for inclusion in the study. If the patient meets all of the eligibility criteria, they wil be enrolled into the study and have either the MiLIF or open procedure depending on the surgoen they present to (i.e., what group their surgeon agreed to participate in).

Description

Inclusion Criteria:

• Patient is between 18 and 75 years of age
• Patient is scheduled for an elective spinal lumbar interbody single level fusion
• Patient is a candidate for posterior unilateral lumbar fusion through a midline incision
• Indication for surgery and dominant symptom of chronic low back and/or leg pain

• Diagnosis of one or more of the following:

  • Primary symptomatic degenerative disc disease confirmed with appropriate imaging studies and/or positive lumbar discography
  • Spondylolisthesis Grade I/II
• The affected motion segment reside in L2-S1 and are adjacent segments
• Patient, or authorized representative, signs a written Informed Consent form to participate in the study, prior to any study mandated determinations or procedure.

Exclusion Criteria:

• Patient has a known fracture in the lumbar spine
• Patient has systemic infection or evidence of any surgical site infection (superficial or organ space)
• Patient has compromised immune system or autoimmune disease (WBC<4000 or >20,000)
• Patient has uncontrolled diabetes
• Patient has a known malignancy
• Prior lumbar fusion attempt; prior laminectomy and/or discectomy are allowed
• Known medical or anatomical condition that would preclude a posterior lumbar fusion using metallic instrumentation (e.g., severe osteopenia)
• Patient with a planned placement of an electric bone stimulator
• Patient with a planned placement of indwelling epidural catheter for a long term pain management
• Patient is pregnant or wishes to become pregnant during the length of the study participation
• Patient is currently in litigation
• Patient is not likely to comply with the follow-up evaluation schedule
• Patient is participating in a clinical trial of another investigational drug or device.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Control; Posterior unilateral interbody fusion using an open approach midline incision (TLIF)	Device: The Atavi System; The primary device in the Atavi system is the Flex Posture retractor and accessories such as dilators and an Expander Instrument. The Atavi System includes instruments used to access the spine by dilation of the overlying tissues, as well as a retracting device that is used to maintain the access. Once the retractor is in place, the visualization components of the system may be used.; Other Names: MIS; Minimally invasive; Atavi; Flex Posure; retractor
Experimental; MiLIF procedure with specialized Atavi instrumentation and minimally invasive visualization capabilities	Device: The Atavi System; The primary device in the Atavi system is the Flex Posture retractor and accessories such as dilators and an Expander Instrument. The Atavi System includes instruments used to access the spine by dilation of the overlying tissues, as well as a retracting device that is used to maintain the access. Once the retractor is in place, the visualization components of the system may be used.; Other Names: MIS; Minimally invasive; Atavi; Flex Posure; retractor

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Clinical Outcomes	MiLIF and Open groups at 3 months post-procedure as defined by the mean Oswestry score

Secondary Outcome Measures

Outcome Measure	Time Frame
Clinical Outcomes	The percent of patients that have a successful fusion at one year post-procedure as measured by radiographs

Collaborators and Investigators

• Sponsor: Zimmer Biomet
• Investigators: Study Director: Joe Murar, M.D., Zimmer Spine

Study record dates

Study Major Dates

• Study Start: April 1, 2004
• Primary Completion (ACTUAL): March 1, 2006
• Study Completion (ACTUAL): June 1, 2009

Study Registration Dates

• First Submitted: November 13, 2008
• First Submitted That Met QC Criteria: November 14, 2008
• First Posted (ESTIMATE): November 17, 2008

Study Record Updates

• Last Update Posted (ESTIMATE): February 16, 2012
• Last Update Submitted That Met QC Criteria: February 14, 2012
• Last Verified: February 1, 2012

More Information

Terms related to this study

• Keywords: Minimally invasive; MIS; Atavi; Flex Posure; retractor; Patients with chronic low back and/or leg pain who are candidates for elective lumbar interbody fusion through a posterior unilateral approach,; for inclusion in the study.; If the patient meets all of the eligibility criteria,; they will be enrolled into the study and have either the MiLIF or open procedure depending on the surgeon they present to; (i.e., what group their surgeon agreed to participate in.)
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Back Pain; Low Back Pain
• Other Study ID Numbers: ATV-03-002; 2007-003