Posterior Cervical Implants used in Spine Survery
Cervical implants are devices surgeons use to decompress and stabilize the spine. These devices are implanted either from the front (anterior) of the spine, or from the back (posterior). Information about posterior implants begins below.
The goals of cervical spine surgery include:
1. Reduce pressure on the nerve(s) by decompression (i.e., surgically removing tissues pushing on a nerve).
2. Stabilize the cervical spine by fusing 2 or more cervical vertebrae together.
Posterior Cervical Approach Implants
Some implants used in posterior cervical fusion procedures are different from those used in anterior spine surgery. The purpose of posterior implants includes:
1. Increase cervical spine stability immediately after surgery.
2. Stabilize the cervical spine during healing.
3. Improve cervical spine alignment (e.g., curvature).
4. Increase the chances for a successful solid fusion.
5. Help reduce the time the patient may need to wear a cervical collar after surgery.
6. And may, in some fracture cases, reduce pressure on the spinal cord and/ or nerve(s).
Plates (or Rods) and Screws: Plates are made with screw holes through which screws anchor the plates into proper position. In a posterior procedure, cervical plates are secured by screws fed into the bony lateral (side) masses (pedicles, dense bone). Before the plate is attached to the spine, bone graft is placed on the lamina next to the plates to stimulate fusion. Alternatively, and perhaps more common today, screws can be placed first and connected to rods. When rods are used, the fusion can be done after locking the system in place. These systems take up less room and are more modular for easing insertion and allow more room for bone graft than plates. Most systems are metal (primarily titanium). Some are made from plastics. Screws are made from metals. Certain newer plates, made from composite materials, dissolve after fusion occurs. Many of these devices are used in an off-label manner, as elected by the surgeon for the needs of the patient.
Clamps are implanted over the tops of adjacent lamina to pull and hold the bony plates together while fusion occurs. Clamps are usually made of titanium. These were early devices; rarely used today.
Hooks attach to the lamina similar to clamps, and are connected by rods. Today, these have little, to no, indication.
Wires: Stainless steel or titanium wires are wrapped around adjacent lamina, or spinous processes, and secured to limit movement between lamina (vertebrae). Bone graft is placed between, or on top of, the lamina to stimulate fusion.
Role of Bone Graft
Whether the spine surgeon implants interbody cages, spacers, plates, clamps, hooks, or wires -- bone graft is needed to promote spinal fusion. There are different types of bone graft. Two common types of bone graft are autograft (patient's own bone) and allograft (donor bone). Some surgeons use other bone growth substitutes to increase the likelihood of successful fusion.
If your surgeon recommends cervical surgery, you can be encouraged that cervical decompression and stabilization procedures are some of the most successful operations spine surgeons perform today. Patients generally have rapid recovery and quickly return to activities of daily living with marked improvement of their symptoms.