Dynamic stabilization devices (DSD) are one of the newest additions to the modern spine surgeon’s armamentaria. DSDs include posterior interspinous process spacers and pedicle-based dynamic rod devices. The devices are used to treat symptomatic lumbar (low back) degenerative disc disease.
These devices offer a less invasive approach and generally leave the intervertebral disc intact, therefore preserving the natural anatomy and motion of the spinal segment while limiting excessive motion. In theory, dynamic stabilization devices may prevent initial progression of degenerative disc disease when used alone or in conjunction with traditional decompression and fusion procedures. In the near future, DSDs may fill the gap between conservative treatment and more aggressive, irreversible surgeries.
Some authors have opined that clinical outcomes for dynamic stabilization systems are comparable to fusion. In light of the high incidence of reoperation of the lumbar spine, DSDs provide an attractive option for some patients to consider.
BNA surgeons have been involved in numerous FDA-controlled clinical trials that evaluated the safety and effectiveness of the dynamic stabilization devices including Wallis® System, DIAM™ Spinal Stabilization System and the ACADIA® Facet Replacement System, which is designed to restore and mimic the facet joints in the lumbar spine.
These devices are currently approved for clinical use in the US:
- Dynesys® System (Zimmer Inc., Minneapolis, MN)
- Coflex™(Paradigm Spine, LLC, New York, NY)
- DIAM (Medtronic Sofamor Danek, Memphis, TN)
- X-STOP (Medtronic Sofamor Danek, Memphis, TN)
- NFix™ II Dynamic Stabilization System (N Spine, Inc., San Diego, CA)
- BioFlex® (BioSpine Co., Ltd, Sungdong-gu, Seoul Korea)
- DSSTM Dynamic Soft Stabilization System (Paradigm Spine, LLC, New York, NY)
- Isobar ™ Spinal System (Scient’x USA, Inc. Maitland, FL)
Figure. X-STOP® Spacer
The X-STOP® Spacer is a lumbar interspinous process distraction device used to treat low back spinal stenosis. X-STOP helps to preserve the functional spinal unit, relieves nerve root compression (impingement) and therefore helps to reduce symptoms. X-STOP is indicated for patients with mild to moderate lumbar spinal stenosis symptoms and especially for patients who experience symptom relief during spinal flexion.
The X-STOP procedure can be performed under local anesthesia in less than an hour with minimal blood loss. It is especially suitable for patients who cannot tolerate general anesthesia.
There is minimal risk of systemic or local complications and little risk of neurological injury. Future treatment options are not compromised.
Spinous Process Fixation Devices
Spinous process fixation devices (SPFD) support minimally invasive surgical techniques by providing supplemental fixation, aiding the stabilization of the spine, and promoting fusion. They can be used as an alternative or in combination with pedicle screw-rod fixation. When used as an adjunct to unilateral pedicle screw fixation, SPFDs potentially minimize the risk of neural injury and other complications while providing sufficient segmental stabilization.
These are some of the devices that have received clearance from the U.S. Food and Drug Administration:
- Aileron™ (Life Spine, Huntley, IL)
- Aspen MIS Fusion System(Biomet, Broomfield, CO)
- Axle® (X-Spine, Miamisburg, OH)
- BacFuse® (RTI Surgical, Alachua, FL)
- BridgePoint™ (Alphatec Spine, Carlsbad, CA)
- Coflex-F® (Paradigm Spine, New York, NY)
- PrimaLOK SP™ (OsteoMed, Addison, TX)
- CD Horizon Spire™ (Medtronic Sofamor Danek, Memphis, TN)
- SP-Fix™® (Globus Medical, Audubon, PA)
- Zip MIS Fusion Systems (Aurora Spine, Carlsbad, CA)