NFlex Stabilization System (Synthes Spine Inc., West Chester, PA)was designed to accommodate this physiologic motion via a bumper element that permits elongation and angulation during flexion and allows compression during extension.
In the unaltered lumbar spine, flexion is necessarily coupled with elongation of the posterior segments; therefore, any device hoping to provide support through physiologic flexion would be required to elongate as well. Though several of the aforementioned devices adequately restrict lumbar extension, reproduction of normal spinal flexion has proved more difficult to emulate. The N-Flex system is semi-rigid and composed of a titanium rod with one end containing a composite titanium-polycarbonate urethane sleeve positioned over the titanium core.
The rod may be attached to pedicle screws in the standard fashion, with one pedicle screw attached to the titanium ring of the sleeve and one or more pedicle screws attached to the solid titanium rod. The composite sleeve is not bonded to the solid titanium rod, allowing compressive loads to be borne primarily by this dynamic structure as opposed to the titanium core. Biomechanical study of this device demonstrated that in all loading modes, the N-Flex device provided a decompressed lumbar segment with sufficient stability (i.e., greater than the intact case) but significantly less rigidity than a similar segment stabilized with a solid rod, suggesting the applicability of this implant as a dynamic fixation device in clinical practice.
The N-Flex device bears the CE mark for non-fusion indications and is not sold in the United States at the present time.NFlex™ is CE marked for non-fusion indications, and is the subject of an N Spine sponsored prospective randomized trial. It is a stand alone motion preservation device for non-fusion outside the US. However, within the U.S., the device is cleared as an adjunct to spinal fusion only. Previously available from N Spine.NFlex is a semi-rigid rod for controlled dynamic stabilization designed to be used with either Synthes Pangea or Click’X pedicle screw systems.
- A rod with transicional rigidity
- One solution for posterolateral fusion with dynamic stabilization
2.-Titanium ring
- Allows for sliding and toggling coupled motion
- Sliding motion as ring slides up and down the core
- Toggling motion as ring toggles against the core
- Polymer bumper that allows for controlled titanium ring motion in flexion, extension, lateral bending and axial rotation at the dynamic level
About Pedicle Screw/Rod–Based Dynamic Stabilization Devices
Dynamic stabilization is a surgical technique designed to allow for some movement of the spine, while maintaining enough stability to prevent too much movement. Pedicle-based dynamic devices were first designed to stabilize the abnormal segment and to unload degenerated discs and facet joints, while maintaining the same level of normal motion.By unloading the pressure on the degenerated disc and facets, pedicle-based dynamic devices have the potential to reduce pain associated with these anatomical structures. Furthermore, these devices can be used to prevent adjacent-segment disease, either by replacing the whole construct with dynamic rods or by “topping off” the rigid instrumented segment with pedicle-based dynamic devices, avoiding an abrupt change from a rigid construct to the more mobile adjacent segment. It has also been argued that using pedicle-based dynamic devices can promote better fusion because of micromovements across endplates, and can protect from implant failure because of better load sharing through the implant. Finally, these devices can be used to stabilize posterior iatrogenic destabilizing surgery, such as wide laminectomy and facetectomy.
About DePuy Synthes
The DePuy Synthes Companies offer the world’s most comprehensive portfolio of orthopaedic and neuro products and services for joint reconstruction, trauma, spine, sports medicine, neuro, cranio-maxillofacial, power tools and biomaterials. Each of the companies that comprise DePuy Synthes Companies has a celebrated history, and each has evolved to meet the needs of the changing orthopaedics and neuro marketplace. The history that weaves the fabric of the DePuy Synthes Companies is one that is rich with innovation and demonstrates sustained leadership in an ever-changing landscape of patient and professional needs.https://www.depuysynthes.com