Vertebral fixation (also known as "spinal fixation") is a neurosurgical procedure in which two or more vertebrae are anchored to each other through a synthetic "vertebral fixation device", with the aim of reducing vertebral mobility and thus avoiding possible damage to the spinal cord and/or spinal roots.
Vertebral fixation devices 
The device used to achieve vertebral fixation is usually a permanent rigid or semi-rigid prosthesis made of titanium; examples include rods, plates, screws, and various combinations thereof. A much less common alternative is the use of a resorbable fixation device, composed of a bio-resorbable material; for example, this could be a polymer capable of being degraded into acidic products, and thus in need of including a buffering agent to avoid acid damage (which may damage the bone adjacent to the device).
The Medical community currently uses several different techniques for stabilizing the posterior region of the spine. The most radical of these techniques is spinal fusion. In recent years/decades spinal surgeons have begun to rely more heavily on mechanical implants, which provide increased stability without so severely limiting the recipient’s range of motion. A number of devices have been developed that allow the recipients near natural range of motion while still providing some support. However, in many cases the support offered by such devices is insufficient, leaving the physician with few other choices than spinal fusion. The Spinal Fixation Device was developed in response to this need for a device that offered additional support to limit the compression on the affected vertebrae while still offering a wide range of motion.
A Spinal Fixation Device is a spinal stabilization device that meets the need prescribed above, namely that it stabilizes an area of the posterior spine while allowing for a significant range of motion and limiting the compression of the affected vertebrae. The device consists of two or more arm assemblies (lateral) connected by one or more telescopic assemblies (vertical). Each arm assembly is composed of a central portion, which connects to the telescopic assembly or assemblies. Left and right arms attach to the corresponding side of the central portion of the arm assembly. Each arm section is directly connected to its individual pedicle by means of pedicle fasteners. The illustration depicts a spinal fixation device. The number 110 refers to pedicle fasteners. 156 refers to the left and right arm attachments of the first and second arm assemblies respectively. 158 refers to the central portions of the arm assemblies themselves. The two vertical cylinders connecting the central portions of the two arm assemblies are the telescopic connectors and "A" depicts how they can be adjusted to limit the compression of the protected vertebrae.
More information about this specific spinal fixation device can be found in The United States Patent Service’s November 13, 2007 publication of new patents. This patent can currently (September 23, 2008) be found on The U.S. Patent Website.
See also 
- The United States Patent Website