(105 days)
When used as a vertebral body replacement device, the InFix® System is intended for use in the thoracic and/or lumbar spine (T3-L5) to replace a collapsed, damaged or unstable vertebral body resected or excised (i.e., partial vertebrectomy procedures) due to tumor or trauma (i.e., fracture). The InFix is designed to restore the biomechanical integrity of the anterior and middle spinal column even in the absence of fusion for a prolonged period. The InFix implant is intended to be used with bone graft.
When used as an intervertebral body fusion device the InFix System is indicated for use with autogenous bone graft at one or two contiguous levels in the lumbosacral region (L2-S1) in the treatment of degenerative disc disease (DDD) with up to Grade 1 spondylolisthesis or retrolisthesis at the involved level(s). DDD is defined as discogenic back pain with degeneration of the disc confirmed by history and radiographic studies. Patients with previous non-fusion spinal surgery at involved level may be treated with the device. Patients should be skeletally mature and have had six months of nonoperative treatment. When used as an intervertebral body fusion device, the InFix implant is intended to be used with supplemental fixation.
For both of the indications listed above, the InFix implant is intended to be implanted via an open anterior approach.
The InFix System is comprised of implants and two configurations of instrumentation. The subject InFix implants are the same design and dimensions as those described in InFix System, VBR submission K031672.
The InFix implant is comprised of two endplates and two struts, which are to be utilized together: with an optional endcap. The InFix System is provided in a range of angles and heights. including the instrumentation (accessories and instruments) necessary to implant the specific system. The current instrumentation is retained in aluminum trays. The new proposed instrumentation is retained in stainless trays.
The InFix implant is manufactured from implantable grade Ti-6AL-4V alloy that conforms to ASTM F-136. The implant is comprised to two opposing Endplates (provided in 0°, 3°, 6° and 9° angles) supported by two vertical Struts available in a range of heights, allowing the surgeon to fix the vertebrae in proper anatomical alignment and lordosis. Each of the Struts includes a load-sharing mechanism that allows a limited amount of strain across the fusion mass while supporting the load bearing surfaces. An Ultra High Molecular Weight Polyethylene (UHMWPE) Endcap may be placed inside the implant prior to packing it with bone graft. The Endcap serves as an optional block of the posterior opening in the implant construct to assist in containing the material inside. Holes in the Endplates provide space for bone in-growth while angled spikes penetrate the vertebral endplates and provide resistance to rotation and migration.
The InFix implant is designed for direct placement between two vertebral bodies. Component sizes and dimensions and the InFix implant depth, width and height are shown below. All dimensions are in millimeters. Strut heights are in 2mm increments.
| Size | InFix Struts | InFix Endplates | |
|---|---|---|---|
| Heights (mm) | Depth (mm) | Width (mm) | |
| Small | 8-14 | 24 | 29 |
| Medium | 8-14 | 26.5 | 32 |
| Large | 8-14 | 29 | 35 |
The InFix implant is assembled and locked in-sity; bone graft is then inserted within the device and up to the anterior rim of the vertebral body.
InFix is implanted using a set of specialized instruments. The subject InFix System specialized instruments (stainless steel trays) are listed in the InFix Anterior Lumbar System Surgical Technique Guide. The current InFix System instruments (aluminum trays) are listed in the InFix Anterior Lumbar Device Surgical Technique Guide. Both instrumentation sets facilitate the insertion and removal of the InFix implants. The InFix implant is provided for single use only.
The InFix® Anterior Lumbar System is an intervertebral body fusion device and vertebral body replacement. The acceptance criteria and the study proving the device meets these criteria are detailed below.
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria Category | Specific Criteria | Reported Device Performance |
|---|---|---|
| Mechanical Performance | Vertebral Body Replacement (VBR): Static and Dynamic Torsion, Static and Dynamic Compression Bending (per ASTM F2077) should demonstrate acceptable performance for intended use, showing substantial equivalence to the predicate device (InFix K031672). | Bench testing per ASTM F2077 confirmed acceptable performance for Static and Dynamic Torsion, and Static and Dynamic Compression Bending, affirming substantial equivalence to the predicate InFix (K031672). |
| Intervertebral Body Fusion Device (IBFD): Static and Dynamic Compression Shear, including Subsidence testing (per ASTM F2077 and ASTM F2267 respectively) should demonstrate acceptable performance for intended use, showing substantial equivalence to the predicate device (Ardis K073202). | Bench testing per ASTM F2077 (Static and Dynamic Compression Shear) and ASTM F2267 (Subsidence) confirmed acceptable performance, affirming substantial equivalence to the predicate Ardis (K073202). | |
| Biomechanical Integrity | Cadaver Testing: The InFix System should perform as intended and demonstrate substantial equivalence to the predicate devices in a cadaveric setting. | Cadaver testing was conducted to ensure the InFix System performs as intended and is substantially equivalent to the predicate devices. |
| Sterilization | Sterilization process (per ISO 17665 and AAMI TIR12) should ensure sterility and demonstrate substantial equivalence to the predicate devices. This includes assessment of dry time and cleaning instructions. | Sterilization was conducted under ISO 17665 and AAMI TIR12, confirming substantial equivalence to the predicate devices, with dry time and cleaning instructions also assessed. |
| Biocompatibility | Materials used in the InFix System should be biocompatible (per ISO 10993-1), based on the same materials as the predicate devices. | Biocompatibility Assessment per ISO 10993-1 confirmed the InFix System materials are biocompatible, based on identical materials to the predicate devices. |
| Design and Functionality | The implant should exhibit the same mechanical and functional design, range of sizes, materials, and performance characteristics for spinal spacers as its predicate device (InFix K031672). The hollow taper design should provide space for bone in-growth. Instrumentation (surgical tools) must facilitate insertion and removal of implants. Implants are for single use only. | The InFix System shares the same technological characteristics, including mechanical and functional design, range of sizes, materials, and performance with its predicate device (InFix K031672). The hollow taper design provides space for bone in-growth. Specialized instruments facilitate insertion/removal. Implants are single-use. |
| Overall Equivalence | The InFix System's performance, intended use, and fundamental scientific technology should remain unchanged and be substantially equivalent to the predicate devices (InFix K031672 and Ardis K073202). The testing must support the addition of the Intervertebral Body Fusion Device indication. | The InFix System testing concluded that its performance, intended use, and fundamental scientific technology remain unchanged and are substantially equivalent to the predicate devices (InFix and Ardis), with testing supporting the new IBFD indication. |
2. Sample Size Used for the Test Set and Data Provenance
The provided document describes non-clinical testing, primarily bench testing and cadaver testing. It does not specify a "test set" in terms of patient data or clinical trials.
- Bench Testing: The sample sizes for the various mechanical tests (Static and Dynamic Torsion, Compression Bending, Compression Shear, Subsidence) are not explicitly stated, but are implied by adherence to ASTM standards (ASTM F2077, ASTM F2267). These standards typically involve a defined number of test specimens to achieve statistical significance.
- Cadaver Testing: The sample size for cadaver testing is not specified.
- Data Provenance: The data is generated from laboratory testing and cadaveric studies, not from human patients. Therefore, terms like "country of origin" or "retrospective/prospective" are not applicable in the usual sense for clinical data. This is pre-clinical data.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
This section is not applicable as the study described is non-clinical (bench and cadaver testing), not involving human patient data where expert review would establish ground truth for a diagnostic or treatment outcome. The "ground truth" for these tests is defined by the ASTM standards and the engineering principles they embody, which dictate acceptable performance limits and measurement methodologies.
4. Adjudication Method for the Test Set
This section is not applicable. Since the testing involves mechanical and cadaveric performance, there is no need for expert adjudication of results in the way it would be done for clinical imaging or diagnostic studies. The results are quantitative measurements against predefined criteria in ASTM standards.
5. If a Multi Reader Multi Case (MRMC) Comparative Effectiveness Study was Done
No, an MRMC comparative effectiveness study was not done. The submission focuses on demonstrating substantial equivalence through non-clinical testing (bench and cadaver studies) against existing predicate devices, not on comparing the effectiveness of the device with and without AI assistance for human readers.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was Done
This section is not applicable. The device is a physical implant (intervertebral body fusion device/vertebral body replacement), not an AI algorithm. Therefore, "standalone algorithm performance" is not relevant.
7. The Type of Ground Truth Used
The ground truth for this device's performance evaluation is based on:
- ASTM Standards: Defined mechanical performance requirements and testing methodologies for spinal implants (e.g., ASTM F2077 for VBR, ASTM F2267 for IBFD). These standards define what constitutes acceptable mechanical behavior.
- Predicate Device Performance: The "ground truth" for substantial equivalence is the established performance and safety profile of the legally marketed predicate devices (InFix K031672 and Ardis K073202). The new device must perform comparably.
- Biocompatibility Standards: ISO 10993-1 provides the criteria for biocompatibility.
- Sterilization Standards: ISO 17665 and AAMI TIR12 dictate the requirements for sterilization.
This is primarily engineering and material science-based ground truth, not clinical outcomes or expert consensus on human patient data.
8. The Sample Size for the Training Set
This section is not applicable. As the device is a physical implant and not an AI algorithm, there is no "training set" in the context of machine learning.
9. How the Ground Truth for the Training Set was Established
This section is not applicable for the same reason as point 8.
§ 888.3080 Intervertebral body fusion device.
(a)
Identification. An intervertebral body fusion device is an implanted single or multiple component spinal device made from a variety of materials, including titanium and polymers. The device is inserted into the intervertebral body space of the cervical or lumbosacral spine, and is intended for intervertebral body fusion.(b)
Classification. (1) Class II (special controls) for intervertebral body fusion devices that contain bone grafting material. The special control is the FDA guidance document entitled “Class II Special Controls Guidance Document: Intervertebral Body Fusion Device.” See § 888.1(e) for the availability of this guidance document.(2) Class III (premarket approval) for intervertebral body fusion devices that include any therapeutic biologic (e.g., bone morphogenic protein). Intervertebral body fusion devices that contain any therapeutic biologic require premarket approval.
(c)
Date premarket approval application (PMA) or notice of product development protocol (PDP) is required. Devices described in paragraph (b)(2) of this section shall have an approved PMA or a declared completed PDP in effect before being placed in commercial distribution.