MLX/XLX ACR Expandable Lumbar Interbody Implants

An Assessment of the Safety and Performance of the MLX® Medial Lateral and XLX ACR® Expandable Lumbar Interbody Implants for the Treatment of Patients With Degenerative Conditions of the Thoracic and/or Lumbar Spine

The objective of this study is to evaluate the safety and performance of thoracic and/or lumbar spine surgery using the MLX and XLX ACR interbody implants as measured by reported complications, radiographic outcomes, and clinical patient outcomes. This study is being undertaken to identify possible residual risks and to clarify mid- to long-term clinical performance that may affect the benefit/risk ratios of the MLX and XLX ACR interbody implants.

Study Overview

• Status: Completed
• Conditions: Degenerative Disc Disease; Spondylolisthesis; Degenerative Scoliosis

Detailed Description

Patients considered for this study will have previously undergone surgery for their spinal condition according to the standard of care of the practitioner. All patients at a given site with surgeries that meet eligibility requirements will be included in the study and available progress notes, medical records, patient-reported outcomes (PROs), radiographs, and complications will be obtained from the medical records.

The safety and performance of the MLX and XLX ACR interbody implants will be assessed using the following:

1. Complications attributable to the use of the associated interbody implant as noted in surgical summaries, progress notes, and hospital records
2. Neurologic status, symptoms, and subject self-reported clinical outcomes (e.g., pain and disability), as available
3. Radiographic outcome (fusion) and description of device status from plain film radiographs and computed tomography (CT) scan(s), as available

• Study Type: Observational
• Enrollment (Actual): 109

Contacts and Locations

Study Locations

• United States
  • California
    • Orange, California, United States, 92868
      • Orthopaedic Specialty Institute
  • Florida
    • Jacksonville, Florida, United States, 32207
      • Lyerly Neurosurgery
  • North Carolina
    • Charlotte, North Carolina, United States, 28207
      • OrthoCarolina Research Institute
    • Charlotte, North Carolina, United States, 28204
      • Carolina NeuroSurgery & Spine Associates

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

At least 90 (75 MLX, 15 XLX ACR) subjects will be enrolled in this multicenter study by at least four investigative sites. A site may have more than one surgeon investigator contributing to the total site enrollment. As a retrospective study, enrollment goals will be determined with the surgeon investigator during site selection by the Sponsor and will be based on available case volume. The site will identify potential subjects who are more than three months from the surgery postoperative time point during the study duration for inclusion in the study.

Description

Inclusion Criteria:

1. Patients who were ≥18 years of age at the time of surgery

2. Underwent spine surgery using either MLX or XLX ACR interbody implant (NuVasive, Inc., San Diego, CA) at:

   1. One or two adjacent thoracic and/or lumbar levels for degenerative disc disease or degenerative spondylolisthesis, or
   2. Any number of thoracic and/or lumbar levels for degenerative scoliosis (defined as >10º coronal curve)
3. Interbody fusion with autograft and/or allograft (i.e., cancellous and/or corticocancellous allograft bone)
4. NuVasive supplemental internal fixation cleared by the applicable regulatory body for use in the thoracolumbar spine

Exclusion Criteria:

1. Use of any bone graft with the associated interbody implant that is not FDA-cleared for use within interbody implants.

   Examples of these include:

   1. Bone morphogenetic protein (BMP) (e.g., Infuse (Medtronic))
   2. Synthetic bone graft extenders (e.g., AttraX (NuVasive), Formagraft (NuVasive), Mastergraft (Medtronic), Vitoss (Stryker), Actifuse (Baxter), nanOss (RTI Surgical), Fibergraft (Prosidyan/Depuy Synthes), ChronOs (Depuy Synthes))
   3. Demineralized bone matrices (DBM) regulated as medical devices by the FDA (e.g., Grafton Putty/Gel (Medtronic), DBX (MTF/Depuy Synthes), Accell Evo3 (IsoTis), Propel Putty/Gel (NuVasive))
   4. Peptide enhanced bone graft (e.g., iFactor (Cerapedics))
2. Previous lumbar fusion surgery at the currently treated level(s) (adjacent-level surgery is acceptable)
3. Systemic or local infection (latent or active) or signs of local inflammation documented at the time of surgery
4. Patient was involved in active litigation relating to the spine during the surgical/postoperative period (worker's compensation claim is allowed if it is not contested)
5. Inadequate bone stock or bone quality documented at the time of surgery
6. Known sensitivity to materials implanted documented at the time of surgery

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
MLX - Medial Lateral Expandable Lumbar Interbody System; Patients who underwent lumbar interbody fusion with the MLX expandable interbody implant will be included in the MLX - Medial Lateral Expandable Lumbar Interbody System cohort.
XLX ACR Interbody System; Patients who underwent lumbar interbody fusion with the XLX ACR expandable interbody implant will be included in the XLX ACR Interbody System cohort.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Rate of Complications	Rate of complications (i.e., safety) attributable to use of the associated interbody implants (MLX or XLX ACR)	At least three months
Proportion of Subjects with Improvement in Neurological Symptoms	The rate of improvement as compared to baseline in preoperative neurological symptoms will be measured using a standard motor/sensory neurological exam.	At least three months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proportion of Subjects with Apparent Radiographic Fusion	Proportion of subjects with apparent radiographic fusion at 12 months or greater postoperative, as imaging is available	12 months or greater

Collaborators and Investigators

• Sponsor: NuVasive
• Investigators: Study Director: Kyle Malone, MS, NuVasive

Study record dates

Study Major Dates

• Study Start (Actual): January 27, 2020
• Primary Completion (Actual): October 23, 2020
• Study Completion (Actual): October 23, 2020

Study Registration Dates

• First Submitted: June 2, 2020
• First Submitted That Met QC Criteria: June 4, 2020
• First Posted (Actual): June 9, 2020

Study Record Updates

• Last Update Posted (Estimated): December 22, 2025
• Last Update Submitted That Met QC Criteria: December 16, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Bone Diseases; Musculoskeletal Diseases; Spinal Diseases; Spondylolysis; Spondylosis; Spondylolisthesis; Intervertebral Disc Degeneration
• Other Study ID Numbers: NUVA.EXP0120