POSTERIOR LUMBAR INTERBODY FUSION (PLIF)
Posterior lumbar interbody fusion (PLIF) is a type of spinal fusion procedure that utilizes a posterior (back area incision) approach to fuse (mend) the lumbar spine bones together (using an interbody fusion technique). Interbody fusion means the intervertebral disc is removed and replaced with a bone spacer (metal or plastic may also be used), in this case using a posterior approach. The posterior technique is often favored when one or two spinal levels are being fused in conjunction with a posterior decompression (laminectomy) and instrumentation (use of metal screws/rods). There are two different types of posterior interbody fusion procedures. The traditional PLIF procedure involves placing two small bone graft spacers, with gentle retraction of the spinal nerves and neurologic structures, one graft on each side of the interbody space (right and left).
PLIF is commonly performed for a variety of painful spinal conditions, such as spondylolisthesis and degenerative disc disease, among others.
Patients are positioned in the prone (lying on the stomach) position, generally using a special operating table/bed with special padding and supports. The surgical region (low back area) is cleansed with a special cleaning solution. Sterile drapes are placed, and the surgical team wears sterile surgical attire such as gowns and gloves to maintain a bacteria-free environment.
A 3-6 inch (depending on the number of levels) longitudinal incision is made in the midline of the low back, directly over the involved spinal levels. The fascia and muscle is gently divided in the midline, and retractors are used to allow the surgeon to visualize the posterior (back part) vertebral arches. After the retractor is in place, an x-ray is used to confirm that the appropriate spinal level(s) is identified.
A complete laminectomy (removal of lamina portion of bone) and foraminotomy (removal of bone spurs from the opening where the nerves leave the spinal column) is typically performed, allowing the nerves to return to their normal size and shape when the compressive lesions are removed. The nerve roots and neurologic structures are protected and carefully retracted, so that the bone spurs can be visualized and removed. Small dental-type instruments and biting/grasping instruments (such as a pituitary rongeur and kerrison rongeur) are used to remove the arthritic, hypertrophic (overgrown) bone spurs and ligamentum flavum. All surrounding areas are also checked to ensure no compressive spurs or disc fragments are remaining.
The PLIF technique includes performing a wide laminectomy and bilateral partial facetectomy to allow visualization and removal of the intervertebral disc. The intervertebral disc is then removed using special biting and grasping instruments (such as a pituitary rongeur, kerrison rongeur, and curettes). Special distractor instruments are used to restore the normal height of the disc, as well as to determine the appropriate size spacer to be placed. A bone spacer (metal or plastic spacers may also be used) is then carefully placed in the disc space. Small metal rods and screws are placed in the upper and lower vertebral bodies, which will provide immediate stability while the bone mends and to increase the fusion rate (percentage of patients where the bone successfully mends together). Fluoroscopic x-rays are taken to confirm that the spacer is in the correct position.
The wound area is usually washed out with sterile water containing antibiotics. The deep fascial layer and subcutaneous layers are closed with a few strong sutures. The skin is closed using stitches or surgical staples. A sterile bandage is applied, and is changed daily while in the hospital.
The total surgery time is approximately 3 to 6 hours, depending on the number of spinal levels involved.
Most patients are usually able to go home 3-5 days after surgery. Patients are instructed to avoid bending at the waist, lifting (more than five pounds), and twisting in the early postoperative period (first 2-4 weeks) to avoid a strain injury. Patients can gradually begin to bend, twist, and lift after 4-6 weeks as the pain subsides and the back muscles get stronger. Occasionally, patients may be issued a soft or rigid lumbar corset that can provide additional lumbar support in the early postoperative period, if necessary.
Patients can shower immediately after surgery, but should keep the incision area covered with a bandage and tape, and try to avoid the water from water hitting directly over the surgical area. After the shower, patients should change the bandage, and dry off the surgical area. The dressing should otherwise be changed every 2-3 days when at home. Patients should not take a bath until the wound has completely healed, which is usually around 2 weeks after surgery.
Return to Work/Sports:
Patients may return to light work duties as early as 2-3 weeks after surgery, depending on when the surgical pain has subsided. Patients may return to moderate level work and light recreational sports as early as 3 months after surgery, if the surgical pain has subsided and the back strength has returned appropriately with physical therapy. Patients who have undergone a fusion at only one level may return to heavy lifting and sports activities when the surgical pain has subsided and the back strength has returned appropriately with physical therapy. Patients who have undergone a fusion at two or more levels are generally recommended to avoid heavy lifting, laborious work, and impact sports.