Dynamic stabilization has been defined as “a system that would alter favorably the movement and load trasmission of a spinal motion segment, without the intention of fusion of the segment”.
Due to the anatomic considerations of the S1 spinous process, interspinous devices are not currently recommended for use at L5-S1. Interspinous implants act to distract the spinous processes and restrict extension, having the effect of reducing the posterior anulus pressures,while not affecting the disc pressure at the adjacent levels and theoretically enlarging the neural foramen.
In extension, interspinous implants increase the canal area (18%), the subarticular diameter (50%), the canal diameter (10%), the foraminal area (25%), and the foraminal width (41%). These results show that an interspinous device prevents narrowing of the spinal canal and foramina in extension.
Due to the anatomic considerations of the S1 spinous process, interspinous devices are not currently recommended for use at L5-S1. Interspinous implants act to distract the spinous processes and restrict extension, having the effect of reducing the posterior anulus pressures,while not affecting the disc pressure at the adjacent levels and theoretically enlarging the neural foramen.
In extension, interspinous implants increase the canal area (18%), the subarticular diameter (50%), the canal diameter (10%), the foraminal area (25%), and the foraminal width (41%). These results show that an interspinous device prevents narrowing of the spinal canal and foramina in extension.
References
- Sengupta DK. Dynamic stabilization devices in the treatment of low back pain. Oerthop Clin North Am; 35:43-56, 2004
- Christie SD, Song JK, Fessler RG. Dynamic Interspinous Process Technology. Spine 30;S16:S73-S78, 2005
- Swanson KE, Lindsey DP, Hsu KY, Zucherman JF, Yerby SA. The Effect of an Interspinous Implant on Intervertebral Disc Pressure. Spine 28;1:26-32, 2003
- Richards JC, Majumdar S, Lindsey DP, Beauprè GS, Yerbi SA. The Treatment Mechanism of an Interspinous Process Implant for Lumbar Neurogenic Intermittent Claudication. Spine 30;7:744-749, 2005
