The recent FDA clearance of the porous interbody system developed by Nvision Biomedical Technologies and Invibio Biomaterial Solutions represents a milestone in spinal fusion: for the first time, the mechanical strength and radiographic visibility of PEEK-OPTIMA™ are combined with the geometric freedom provided by Bond3D™ 3D printing
What Does This Mean for ALIF and ACIF?
- Implants are now available in multiple footprints and lordotic angles, covering most cervical and lumbar indications.
- The interconnected porous matrix (pores ~300 µm) supports multidirectional bone ingrowth, improving fixation and speeding up fusion.
- The elastic modulus of PEEK (≈ 3–4 GPa) closely matches that of cancellous bone, reducing the risk of subsidence—a common complication with titanium cages.
PEEK Radiolucency vs. Titanium
| Feature | PEEK-OPTIMA™ | Titanium |
|---|---|---|
| CT/MRI artifacts | Minimal — clear fusion imaging | High — shadows |
| Postoperative follow-up | Clear view of bony bridging and neural canal | Challenging interpretation |
| Interference with radiotherapy | Low (ideal for oncology patients) | High — causes over/underdosing |
Additionally, radiolucency prevents metal overlap on dynamic views, crucial for assessing residual motion in disc arthroplasty. Invibio summarizes these benefits on its clinical portal.
3D Printing Redefines the Rules
The Bond3D™ platform sinters implant-grade PEEK-OPTIMA™ filament layer by layer, alternating solid and porous regions in a single construct. This was impossible with traditional machining, which required coatings or surface-only porosity.
Integration with Our Disc Replacement Program
In our unit, we use radiolucent PEEK disc prostheses (and CF-PEEK in specific cases):
- Accurate monitoring: artifact-free imaging allows evaluation of segment motion and endplate integrity on dynamic CT or MRI.
- Mechanical compatibility: matching bone modulus reduces endplate stress (stress shielding) and preserves disc height.
- Synergy with porous implants: when combining disc replacement with adjacent-level fusion, PEEK-OPTIMA™ porous cages ensure uniform biomechanics, lowering adjacent-level disease risk.
- Oncology and radiotherapy planning: PEEK minimizes dose scatter in radiosurgery or proton therapy—unachievable with titanium.
Conclusions & Key Points
- First 3D-printed PEEK ALIF/ACIF system: validates 3D printing as a true alternative to titanium in spinal surgery.
- Integrated porosity: enhances fusion biology without sacrificing strength.
- Total radiolucency: optimizes postoperative follow-up and adjuvant therapies.
- Immediate applicability to our cervical and lumbar disc replacement protocols, ensuring material and diagnostic consistency in hybrid reconstructions.
The introduction of these devices paves the way for clinical trials directly comparing arthroplasty vs. porous PEEK fusion, a research avenue we will closely monitor to deliver increasingly personalized, minimally invasive solutions to our patients.
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