Retro Comparison of Subsidence Following Interbody Devices in Lumbar Spine

A Retrospective Comparative Analysis of Interbody Fusion Devices in the Lumbar Spine for Occurrence of Subsidence

The objective of this retrospective study is an investigational clinical follow-up, of patients treated with interbody fusion devices (IBFD), both expandable (EXP) and static (STC), according to their intended use and cleared labeling to understand IBFD design and technique characteristics that affect occurrence rates of subsidence.

Patients treated with IBFD's (both EXP and STC) according to their intended use and cleared labeling

1. EXP IBFD's that expand in width and height demonstrate reduced occurrence of subsidence post-operatively when compared to EXP IBFD's that expand in height only and STC IBFD's.
2. EXP IBFD's that are comprised of multi-material composition with Polyetheretherketone (PEEK) endplate contacting surfaces demonstrate reduced occurrence of subsidence on post-operative radiographs when compared to EXP and STC IBFD's that are primarily comprised of Ti with Ti endplate contacting surfaces.
3. achieve radiographic fusion at a rate consistent with the state-of-the-art
4. achieve significant improvements in pain and function compared to baseline
5. experience adverse events at a frequency comparable to reported rates for TLIF or PLIF surgery
6. not demonstrate any intraoperative complications during the implant process
7. operative approach does not correlate with increased rates of subsidence

Study Overview

• Status: Completed
• Conditions: Degenerative Disc Disease (DDD)
• Intervention / Treatment: Device: Lumbar Interbody Fusion Devices

• Study Type: Observational
• Enrollment (Actual): 465

Contacts and Locations

Study Locations

• United States
  • California
    • San Francisco, California, United States, 94143
      • University of California San Francisco
  • New York
    • New York, New York, United States, 10016
      • New York University Langone Health
  • North Carolina
    • Charlotte, North Carolina, United States, 28204
      • Carolina NeuroSurgery & Spine Associates
  • Pennsylvania
    • Bensalem, Pennsylvania, United States, 19020
      • Rothman Orthopaedic Institute

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 110 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Skeletally mature individuals with degenerative disc disease (DDD) of the lumbar spine at one or two contiguous levels from L2 to S1, who were treated with TLIF or PLIF surgery using an EXP or STC IBFD according to the surgeon's and patient's choice, as part of the standard of care.

Description

Inclusion Criteria:

1. The patient was treated with TLIF or PLIF surgery using the IBFD according to the cleared labeling, based on the surgeon's clinical judgment and patient-specific decision making. Based on the product labeling, the patient must:

1. Was at least 18 years of age and skeletally mature at the time of surgery
2. Had clinical and radiological evidence of DDD of the lumbar spine
3. Undergone treatment with the IBFD with autogenous bone graft and/or allogeneic bone graft composed of cancellous and/or corticocancellous bone at 1 or 2 contiguous levels from L2 to S1

Exclusion Criteria:

1. History of fusion surgery or large laminectomy at L2 to S1 prior to treatment with the IBFD(s) Spondylolisthesis unable to be reduced to grade 1 as part of the surgical procedure
2. Surgery with the IBFD(s) at more than 2 contiguous levels
3. Surgery with the IBFD(s) at levels outside the range of L2 to S1
4. Treated with any bone grafting material other than autogenous or allogenic bone graft in the device(s) or surrounding disc space
5. Any contraindications listed in the cleared product labeling
6. Osteoporosis, Other Systemic Bone D.O. T score ≤ -1.5
7. BMI > 40
8. Systemic Infection
9. H/O IV Drug Use
10. Cancer

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of Subsidence	Radiographic subsidence immediately postoperatively (first erect), at 12 months, and at 24 months as evaluated by an independent reviewer. Where subsidence is defined as ≥ 2mm cage penetration of the cephalad, caudal end plate, or both. Intraoperative subsidence will be classified when fluoroscopic images identify end plate violation, and postoperative subsidence is classified by the absence of violation on intraoperative fluoroscopy, but present on 12-month lateral radiographs and/or 24 months.	24 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of Fusion	Radiographic fusion at 12 months and at 24 months follow-up, as evaluated by up to 3 independent reviewers (2 primary reviewers and 1 adjudicator, as needed for disagreements). Fusion status will be determined according to the Bridwell-Lenke grading system (Bridwell et al. 1995), with grades 1-2 accepted as "Fused" and grades 3-4 accepted as "Not Fused." For subjects determined to be fused at 12 months, additional X-rays will not be required at 24 months unless the treating surgeon determines that radiographs are otherwise needed for the patient. The last-observation-carried-forward (LOCF) approach will be employed for 24-month fusion assessments where additional radiographs were not collected beyond 12 months.	24 months
Incidence of End Plate Violation	Incidence of end plate violation determined based upon operative reports and medical records.	12 months
Visual Analog Scale (VAS) Scores for Leg Pain, if available	Comparison of VAS scores for leg pain between baseline and 12 months post-operatively and baseline and 24 months post-operatively. The scores range from 0 to 100, with higher numbers indicating more pain.	24 months
VAS Scores for Back Pain, if available	Comparison of VAS scores for back pain between baseline and 12 months post-operatively and baseline and 24 months post-operatively. The scores range from 0 to 100, with higher numbers indicating more pain.	24 months
Oswestry Disability Index (ODI) Scores, if available	Comparison of ODI scores between baseline and 12 months post-operatively and baseline and 24 months post-operatively. The scores range from 0 to 100, with higher numbers indicating more disability.	24 months
Incidence of Device and/or Procedure-Related Adverse Events	Incidence of device and/or procedure-related adverse events determined based upon operative reports and medical records.	24 months

Collaborators and Investigators

• Sponsor: Spine and Scoliosis Research Associates
• Investigators: Principal Investigator: Aaron Buckland, MD, SSRA Inc.

Study record dates

Study Major Dates

• Study Start (Actual): August 16, 2022
• Primary Completion (Actual): July 16, 2025
• Study Completion (Actual): July 16, 2025

Study Registration Dates

• First Submitted: September 7, 2022
• First Submitted That Met QC Criteria: September 7, 2022
• First Posted (Actual): September 10, 2022

Study Record Updates

• Last Update Posted (Actual): October 20, 2025
• Last Update Submitted That Met QC Criteria: October 15, 2025
• Last Verified: October 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Bone Diseases; Musculoskeletal Diseases; Spinal Diseases; Intervertebral Disc Degeneration
• Other Study ID Numbers: CP-000003

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