ClinicalTrials.gg
Active, not recruitingNCT05583864Updated Jul 6, 2026

Lumbar Fusion With Porous Versus Non-Porous Cages

An interventional study of CONDUIT Porous Titanium Spinal Cage and PROTI 360 Titanium-Coated PEEK Spinal Cage in Spinal Fusion, Lumbar Fusion and Arthrodesis, sponsored by Francis Farhadi. Active, not recruiting at 1 site in United States. Open to participants aged 18 Years to 80 Years. Per ClinicalTrials.gov, last updated 2026-07-06.

Sponsored by Francis Farhadi · Not applicable, Interventional, and Treatment

Phase
Not applicable
Study type
Interventional
Enrollment
108
Allocation
Randomized
Ages
18 Years to 80 Years
Sex
All
01

Study summary

The objective of this single site, randomized controlled trial is to assess and compare radiographic and clinical outcomes in patients who are to undergo lumbar interbody fusion procedures (TLIF), supplemented with pedicle screw instrumentation, using one of the following interventions:

  1. Porous titanium cages
  2. Non-porous titanium-coated poly-ether-ether-ketone (PEEK) cages.
Read the detailed description

This single-center randomized controlled trial will prospectively evaluate the safety and efficacy of porous titanium cages supplemented with a pedicle screw system as compared to titanium-coated PEEK cages currently used in routine fashion for lumbar interbody fusion procedures.

These cages are FDA approved and the study is designed to compare the outcomes of subjects receiving either implant. This study will capture clinical and radiographic outcomes on patients up to 2 years post-operatively. Both cages will be used in conjunction with milled local autograft bone generated as part of the spinal fusion procedure (no iliac crest autograft will be utilized).

This study will enroll a maximum of 108 subjects (approximately n = 54 per group), with subjects followed for a minimum of 12 months post-surgery. A total cage sample size of 108 cages (n = 54 cages per group) was calculated with a power of 80% (alpha =0.05) and based on the assumption that 55% of cages in the titanium-coated PEEK group would achieve a solid fusion by 6 months, as compared to 80% in the porous titanium group. Up to two cages may be placed in a single subject. Therefore, it is possible that the maximum number of human subjects would be 54 if all are multi-level procedures. Since there are always mixtures of single and multi-level procedures, the actual number of subjects will be closer to 80, with a maximum ceiling of 108.

These assumptions are based on prior imaging findings in patients undergoing TLIF procedures using these cages. An interim analysis is planned once, at minimum, half of the cage accrual is met. In the case early findings show a statistical difference in the primary outcome between the two cages, enrollment will be allowed to cease as investigators are unlikely to maintain clinical equipoise to continue randomizing patients. Conversely, if the interim analysis suggests that statistical significance is unlikely, the investigators will be allowed to choose to close the trial early for futility.

Randomization will occur in 4 and 6 subject blocks to ensure comparability and enhance blinding for this sample size. Subjects will be further stratified for smoking due to the significant risk it places on successful fusion outcomes.

02

Conditions studied

  • Spinal Fusion
  • Lumbar Fusion
  • Arthrodesis
  • Spondylolisthesis
  • Pseudarthrosis

Keywords

  • Spinal Cage
  • PEEK
  • Pseudarthrosis
  • Spondylolisthesis
  • Titanium
  • Fusion
  • Transforaminal
  • Interbody
  • Posterolateral
  • CONDUIT
  • PROTI 360
  • TLIF
03

In context

Ankylosis

83 studies on the registry are indexed under Ankylosis; 18 are open to participants now.

This study's planned enrollment of 108 is close to the median of 99 across 34 interventional studies indexed under Ankylosis.

Browse Ankylosis studies →

Lead sponsor

Francis Farhadi is the lead sponsor of 9 studies on the registry; 7 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 80 Years
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

Patients will be considered for inclusion if:

  1. They are scheduled to undergo combined interbody and posterolateral spinal fusion surgery using either the DePuy Synthes CONDUIT™ porous titanium cage or the DePuy Synthes PROTI 360º™ non-porous titanium-coated PEEK cage in conjunction with local autograft bone, and supplementation with a pedicle screw system.
  2. They are over the age of 18 years old.
  3. They have been unresponsive to conservative care for a minimum of 6 months.
  4. They are in the investigator's opinion, be psychosocially, mentally, and physically able to fully comply with this protocol including the required follow-up visits, the filling out of required forms, and have the ability to understand and give written .

Exclusion criteria

Exclusion Criteria:

Certain comorbidities and medical statuses may render patients ineligible for surgery, or put them at an increased risk for complications or injury by participating in the study. Therefore, patients will be excluded from enrollment if:

  1. They have had previous lumbar arthrodesis surgery.
  2. They require additional bone grafting materials other than local autograft bone.
  3. There is inadequate tissue coverage over the operative site.
  4. There is an open wound local to the operative area, or rapid joint disease, bone absorption, or osteoporosis.
  5. Subject has a condition requiring medications that may interfere with bone or soft tissue healing(i.e., oral or parenteral , immunosuppressives, methotrexate, etc.).
  6. Subject has an active local or systemic infection.
  7. Subject has a metal sensitivity/foreign body sensitivity (cages will be implanted).
  8. Subject is morbidly obese, defined as a (BMI) greater than 40.
  9. Subject has any medical condition or extenuating circumstance that, in the opinion of the investigator, would preclude participation in the study.
  10. Subject is currently involved in another drug or device study that could confound study data.
  11. There is a history (present or past) of substance abuse (recreational drugs, prescription drugs or alcohol) that in the investigator's opinion may interfere with protocol assessments and/or with the subject's ability to complete the protocol required follow-up.
  12. Subjects who are pregnant or plan to become pregnant in the next 12 months or who are lactating. This restriction is due to the inherent risk radiography presents to an embryo or fetus and is considered standard of care.
  13. Subject is involved in or planning to engage in litigation or receiving Worker's Compensation related to neck or back pain. Participation may effect the assessments made by case workers and legal teams.
  14. Subject is a prisoner.
Terms in these criteria, in plain language(4)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

Corticosteroids (steroids)

Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.

Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.

BMI (body mass index)

Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.

What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.

Investigational drug or device

A drug or device being studied in a clinical trial.

It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.

05

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Triple (Participant, Care provider, Investigator)
Enrollment
108 participants (estimated)

Study arms

  • Active comparator
    CONDUIT Porous Titanium Spinal Cage

    Solid titanium spinal cage, infused with microscopic, porous canals to allow for adhesion and proliferation of bone graft factors contributing to spinal ossification, and ultimately, spinal fusion between vertebrae demonstrating instability.

    Device: CONDUIT Porous Titanium Spinal Cage

  • Active comparator
    PROTI 360 Titanium-Coated PEEK Spinal Cage

    Spinal cage composed primarily of a medical-grade polymer: poly-ether-ether-ketone (PEEK), with a titanium coating that is etched, but lacking porous features. These design features also attempt to stimulate spinal vertebrae fusion through bone-graft ossification and enhance vertebral stability.

    Device: PROTI 360 Titanium-Coated PEEK Spinal Cage

Interventions

  • DeviceCONDUIT Porous Titanium Spinal Cage

    Already included in arm/group descriptions.

    Also known as: DePuy Synthes CONDUIT™

  • DevicePROTI 360 Titanium-Coated PEEK Spinal Cage

    Already included in arm/group descriptions.

    Also known as: DePuy Synthes PROTI 360º™

06

What researchers measure

Primary outcomes

  1. Brantigan-Steffee-Frasier (BSF) Fusion Scale

    Graded radiographic evaluation of ossification and/or pseudarthrosis between vertebrae. The evaluation applies a three-level scale of fusion success: BSF-1: Radiographical pseudarthrosis BSF-2: Radiographical locked pseudarthrosis BSF-3: Radiographical fusion Radiographic Success: Radiographic success is defined by radiographical fusion (BSF-3) presenting bone bridges within at least half of the fusion area with at least the density originally achieved at surgery. Radiographic Failure: Radiographic failure is defined by radiographical pseudarthrosis (BSF-1 or -2)

    Time frame: Six months following procedure

Secondary outcomes

  1. Oswestry Disability Index (ODIv2.1a)

    Subject self-assessment survey pertaining to quality-of-life and pain measures. Scale ranges from 0-100%. The higher the percentage, the lower the quality of life and the greater the pain.

    Time frame: Preoperative, three, six, twelve, and twenty-four month follow-ups.

  2. Neurological Pain Scale for Back and Legs

    Subject self-assessment survey pertaining to pain presence in legs and back. The scale runs from 0-10, with 0 indicating no pain and 10 the worst pain possible.

    Time frame: Preoperative, three, six, twelve, and twenty-four month follow-ups.

  3. PROMIS-10 Global

    Patient reported survey to rate quality-of-life and pain experience throughout life of study. Initially gives a raw score for both physical and mental well-being between 4 and 20, which is converted into a T-score between 16.2 and 67.7. The T-score is directly correlated with what is being evaluated. In other words, the higher the T-score, the higher the quality of life and the lower the pain.

    Time frame: Preoperative, three, six, twelve, and twenty-four month follow-ups.

07

Study locations

1 site
08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Jul 6, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT05583864
Lead sponsor
Francis Farhadi
Responsible party
Francis Farhadi (Associate Professor, Neurosurgery, University of Kentucky) — Sponsor-investigator
First posted
Oct 18, 2022
Start date
Nov 1, 2022
Primary completion
Jun 10, 2026
Completion
Jun 2027 (estimated)
Last update
Jul 6, 2026

Study contacts

Francis Farhadi, MD, PhD
principal investigator · University of Kentucky
Craig van Horne, MD, PhD
study director · University of Kentucky

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
Yes
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is active, not recruiting, as verified in Jul 2026. You cannot join it, but the record below documents what was studied.

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