What is a
Minimally Invasive Posterior Interbody Fusion?
Minimally Invasive Posterior Interbody Fusion (PLIF) requires a bone graft at the surgical site of the spine. With a bone graft, the body’s biological response creates bone growth between the associated vertebrae, which eliminates the potential for instability in that segment.
Reasons for Minimally Invasive PLIF include spondylolisthesis, degenerated lumbar discs, back pain, fracture, tumor, recurrent herniated discs, and failed back syndrome. Patients who have lumbar fusion surgery often have pinched nerves from herniated discs or spinal stenosis, so PLIF is often performed in conjunction with microlumbar discectomy or lumbar laminectomy.
Instead of a large incision, minimally invasive spine fusion surgery involves approximately 1 inch incision, at the surgical level, off to one side of the middle of the back. An X-Ray with fluroscopy confirms the accuracy of the incision. Tubular retractors are placed in sequence over the dilators to split the muscles, granting access to the spine without stripping significant amounts of muscle from the spine. This technique reduces postoperative pain and muscle injury.
Once the initial dilator is in place, larger dilators are progressively introduced to increase the surgical opening. Once sufficient space has been created to perform the procedure, retractors are used to hold the soft tissue back, and the dilators are removed. Using a microscope to improve surgical lighting and vision, the surgeon completes the decompression and fusion with precision and accuracy.
Using specially designed instruments, the disc is incised and removed, and a bone graft is placed between the vertebrae. The bone graft may be obtained from the patients hip bone, or in some cases, insurance will cover the use of bone morphogenic protein (BMP), a recombinant DNA product. Local bone or bone harvested from a cadaver may also be used. When the bone graft heals, it becomes a solid bridge of bone which connects the upper and lower levels of the spine. Posterolateral bone is often added to increase the strength and stability of the fusion. Titanium screws are inserted into the bones above and below the graft which will then hold connecting surgical rods into place.
An important note is that Texas Center for Spine Surgery is the pioneer for the use of intraoperative neuromonitoring in minimally invasive spinal fusion. The neuromonitor ensures accuracy of pedicle screw placement and reduces the potential for radiation exposure to the patient and surgical team. The safety of lumbar fusion procedures is effectively improved.