Posterior Lumbar Interbody Fusion (PLIF) & Transforaminal Lumbar Interbody Fusion (TLIF)

Overview and Indications

Posterior lumbar interbody fusion (PLIF) and transforaminal lumbar interbody fusion (TLIF) are two types of spinal fusion procedures that utilize 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). A newer technique, called a TLIF (transforaminal lumbar interbody fusion), involves placing only one bone graft spacer in the middle of the interbody space, without retraction of the spinal nerves.

PLIF and TLIF procedures are commonly performed for a variety of painful spinal conditions, such as spondylolisthesis and degenerative disc disease, among others.

Surgical Technique

The surgery is performed utilizing general anesthesia. A breathing tube (endotracheal tube) is placed and the patient breathes using a ventilator during the surgery. Preoperative intravenous antibiotics are given. 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 TLIF technique includes performing a complete unilateral (one side only) 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.

Post-Operative Care

Most patients are usually able to go home 3-5 days after surgery. Before patients go home, physical therapists and occupational therapists work with patients and instruct them on proper techniques of getting in and out of bed and walking independently. 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.

Brace

Patients are generally not required to wear a back brace after surgery. Occasionally, patients may be issued a soft or rigid lumbar corset that can provide additional lumbar support in the early postoperative period, if necessary.

Wound Care

The wound area should remain covered with a gauze bandage secured in place with tape. The area should be kept clean and dry. The bandage should generally be changed every 1-2 days, especially after showering.

Shower/Bath

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.

Driving

Patients may begin driving when the pain has decreased to a mild level, which usually is between 7-14 days after surgery. Patients should not drive while taking pain medicines (narcotics). When driving for the first time after surgery, patients should make it a short drive only and have someone come with them, in case the pain flares up and they need help driving back home. After patients feel comfortable with a short drive, they can begin driving longer distances alone.

Return to Work and 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.

Doctor's Visits and Follow-Up

Patients will return for a follow-up visit to see the doctor approximately 12-14 days after surgery. The incision will be inspected. The incision will be inspected and the stitches or staples will be removed. Medications will be refilled if necessary. Patients will usually return to see Dr. Spoonamore or Dr. Smith every 4-6 weeks thereafter, and an x-ray will be taken to confirm the fusion area is stable and healing appropriately. At 8-12 weeks after surgery, patients will be given a prescription to begin physical therapy for gentle back exercises.

Results and Outcome Studies

The results of posterior lumbar interbody fusion (PLIF) and transforaminal lumbar interbody fusion (TLIF) surgery in the treatment of symptomatic spondylolisthesis and degenerative disc disease are generally excellent. Numerous research studies in medical journals demonstrate greater than 90-96% good or excellent results from PLIF and TLIF surgery. Most patients are noted to have a significant improvement of their back pain and return to many, if not all, of their normal daily and recreational activities.

Selected Bibliography

Hackenberg L, Halm H, Bullmann V, et al. Transforaminal lumbar interbody fusion: a safe technique with satisfactory three to five year results. Eur Spine J 2005;14:551-8.

Harris BM, Hilibrand AS, Savas PE, et al. Transforaminal lumbar interbody fusion: the effect of various instrumentation techniques on the flexibility of the lumbar spine. Spine 2004;29:E65-70.

Heth JA, Hitchon PW, Goel VK, et al. A biomechanical comparison between anterior and transverse interbody fusion cages. Spine 2001;26:E261-7.

Humphreys SC, Hodges SD, Patwardhan AG, et al. Comparison of posterior and transforaminal approaches to lumbar interbody fusion. Spine 2001;26:567-71.

La Rosa G, Conti A, Cacciola F, et al.. Pedicle screw fixation for isthmic spondylolisthesis: does posterior lumbar interbody fusion improve outcome over posterolateral fusion? J Neurosurg Spine. 2003;99:143-50.

Lowe TG, Tahernia AD. Unilateral transforaminal posterior lumbar interbody fusion. Clin Orthop 2002;394:64-72.

Madan S, Boeree NR. Outcome of posterior lumbar interbody fusion versus posterolateral fusion for spondylolytic spondylolisthesis. Spine. 2002;27:1536-42.

Rosenberg WS, Mummaneni PV. Transforaminal lumbar interbody fusion: technique, complications, and early results. Neurosurgery. 2001;48:569-74.

Salehi SA, Tawk R, Ganju A, et al. Transforaminal lumbar interbody fusion: surgical technique and results in 24 patients. Neurosurgery 2004;54:368-74; discussion 74.

Whitecloud TS, Roesch WW, Ricciardi JE. Transforaminal interbody fusion versus anterior-posterior interbody fusion of the lumbar spine: a financial analysis. J Spinal Disord. 2001;14:100-3.