PLIF is a type of arthrodesis for the fusion of two vertebrae so it is called like that. Intersomatic refers to the fact that we are going to act on the vertebral and posterior lumbar body, it talks about the approach to surgery.
How is PLIF performed?
Once asleep under general anaesthesia, the surgeon will operate the vertebral segment by accessing from behind. When opened, he first finds the lumbar paravertebral muscles that will have to detach from the bone and set aside to access the vertebrae.
The next thing that is found is the lamina, which is the bone that covers the vertebral canal (where the medulla and nerve roots pass) behind. In this type of intervention, the surgeon will cut this bone, that means, remove the lamina. It is what is called laminectomy. Sometimes the posterior joints are also removed when there is space to leave the nerve root.
When the lamina is removed, the nerve roots are directly visible. These roots must be separated to access the disk behind.
The disk is removed to put two boxes that occupy the space between the two vertebral bodies. These synthetic boxes contain bone graft to allow a fusion of the two vertebral bodies.
To hold everything in place, pedicle screws are placed in each vertebra and then fastened together with bars. Once done, a bone graft is added to the back to increase the chances of fusion.
Advantages of posterior lumbar interbody fusion (PLIF)
Techniques such as this that put an implant between the vertebral bodies achieve a higher rate of bone consolidation. If we compare with instrumented posterolateral arthrodesis, we will have a higher percentage of success in achieving fusion of the operated vertebral segment.
Added to this, it has the advantage of being able to act better on the structures that may be compressing the nerves. By separating the muscles and removing the lamina, the nerve roots and surrounding structures can be visualized. This way it is easier to act on it.
Regarding the surgery performed in the anterior approach, we avoid the large blood vessels in the body that pass by. In this way, we get rid of the serious complications that can occur when injuring these structures.
You might also want to read: What is an Anterior Lumbar Interbody Fusion (ALIF)?