Posterolateral Fusion (PLF)

An Overview of Posterolateral Fusion (PLF)

A posterolateral fusion (PLF) in the lumbar or thoracic spines is one of the simplest and easiest lumbar fusions to perform. Do not confuse this fusion with a PLIF (posterior lumbar interbody fusion) as the PLIF is much more complex and similar to a TLIF fusion.

What is surgically required for a posterolateral lumbar fusion is exposure of the transverse processes and facets. These structures are located close to the skin surface in the back and sides of the spine (hence the term “posterolateral”) and are not part of the spinal canal. This is the original fusion has been utilized by spine surgeons for at least 60 years with good results.

The fusion occurs when a certain set of circumstances are followed. The bone surfaces that are to be fused are exposed, cleaned of any tissue attachments and then “burred”, damaging the outer “skin” or cortex of the bone. This sets off a healing reaction.

When bone graft material is placed between two separate but “injured” bony surfaces, the bone “interprets” that a fracture has occurred. Normally, the injured cortical surface would regrow without expanding to restore its cortical “skin”. However, when bone graft is placed between two injured surfaces, the bone grows in between these surfaces. A fusion of these two vertebrae is the result.

Motion and Pedicle Screws

If motion is allowed between these two surfaces, this motion will cause disruption of bone growth, as healing bone cells require “quiet”. Motion disrupts the growing bone cells and prevents the two surfaces from joining. This is why immobilization is necessary. This is the same reason that casts are necessary for fractures of the arms or legs-to stop motion and allow for healing.

The purpose of screws and rods used in fusion is to become an “internal cast”. These implants immobilize the two bone surfaces so that bone can grow and fully join these two vertebrae together without being disrupted. The rest of the spine can still be mobile but the instrumentation will keep the individual fusion segments relatively immobile.

You might ask if the screws are still necessary after the fusion is fully solid. This hardware does become superfluous after the vertebrae become joined together. However, it is rare to have instrumentation removed after a successful fusion. These screws and rods left in place rarely cause discomfort. The hardware can be removed if necessary in a simple surgery but this occurs less than 5% of the time.

Are you a candidate for posterolateral fusion (PLF)?

Would you like to consult with Dr. Corenman about your condition?
You can set up a long distance consultation to discuss your
current X-rays and/or MRIs for a clinical case review.

REQUEST A SECOND OPINION

(Please keep reading below for more information on this treatment.)

Indications for Posterolateral Fusion

The posterolateral fusion (PLF) may be utilized if there is no need to enter the canal and retract the nerve roots to get to the disc space.

The posterolateral fusion (PLF) does not preclude decompression such as a microdiscectomy or laminotomy to decompress the nerve roots or spinal canal. In fact, it is quite common to add one of these decompressions to the posterolateral fusion. See these decompression procedures in their respective sections on this website to understand what is involved with root decompression.

This posterolateral type of fusion is indicated in two sets of patients. Since this is a “less invasive” surgery for shorter one or two levels, those individuals who have lower demands on the lumbar spine are good candidates. An example would be an active patient with a more relaxed lifestyle who participates in golfing, biking and hiking.

The other type of individual who would benefit is the one that needs a longer fusion (more than 2 levels). Procedures like a TLIF or lateral fusion procedures for three or more levels are more complex and would require longer anesthesia times. The length of surgery risks for those fusions generally would not be beneficial to the patient.

This posterolateral fusion can however be utilized along with a more complex fusion at the base of the spine such as a TLIF to gain a longer construct with better chance of solid fusion. Longer fusions have a greater failure rate at the base of the fusion (at the sacrum, L5-S1) and a TLIF will reduce this failure rate substantially.

The most common example would be of a fusion from L1-S1 due to a degenerative scoliosis. This fusion could utilize a TLIF at L5-S1 and a posterolateral fusion at L1-L5 to create a hybrid fusion.

Another example of indications for a longer posterolateral fusion (where it would be more dangerous to involve the anterior column) is in a patient who needs a thoracolumbar fusion due to Scheuermann’s disorder or a fracture. The spinal cord generally ends at the L1 vertebra. The presence of the spinal cord in front would make an approach to this disc space more risky.

The PLF fusion can be performed with or without BMP (bone morphogenic protein). BMP tends to significantly increase the rate of fusion. See the section on BMP to understand this product.

To learn more about posterolateral fusion (PLF), or to discuss if you are a candidate for a lumbar fusion with a spine surgeon and back specialist in the Vail, Aspen, Denver and Grand Junction, Colorado area, please contact the office of Dr. Donald Corenman.

Related Content

Click to Enlarge. This is a degenerative spondylolisthesis of L4-5 (arrow). This would only require a one level PLF fusion to repair the slipped vertebra.

Click to Enlarge. This is a two level fusion of L3-5 to repair a two level degenerative spondylolisthesis.

Click to Enlarge. This is a front to back view of the same surgery as #2.

This is a burst fracture of L4 with canal compromise and cord injury (arrow).

Click to Enlarge. This is the post-operative picture of the surgical repair of the burst fracture. The PLF reduced the canal compromise and paralysis was eliminated.

Click to Enlarge. This is a front to back (AP) image of a scoliosis. The patient had incapacitating back pain.

Click to Enlarge. This is the surgical repair of that scoliosis. The screws and rods have straightened the deformity in a typical posterolateral fusion (PLF).

Click to Enlarge. Side-view of the scoliosis repair. Patient had full relief of her spine pain.

Donald Corenman, MD, DC

Average rating:

81 reviews

Eric S

Sep 26, 2021

by Eric S on Donald Corenman, MD, DC

Successful pars repair at 46 years old

Back in November of 2018 (at 46 years old) I came from Vancouver BC to have a pars repair done with Dr. Donald Corenman at the Steadman Clinic in Vail Colorado. I'm finally posting this review nearly three years later in late 2021. The reason I waited so long was I wanted to know the final result before I posted my review. Unfortunately in that time Dr. Corenman has retired. Nevertheless, I want to post this review of Dr. Corenman and his staff at the Steadman Clinic in their excellent treatment of my L5 pars interarticularis.

I fractured my pars at age 42 back in 2014 when rolling on the gym floor, and was denied treatment by the Canadian healthcare system, probably due to my age. First my GP told me there was no surgical option for a pars defect, which was quite incorrect! I tried to live with it, but the symptoms worsened (periodic random spine slippage and weeks of resultant pain after just bending over to tie my shoe, so I eventually learned to mostly squat and hardly bend). When I finally consulted with Canadian spine surgeons, I was told they believed my pars defect had been congenital (since birth). This was absurd, considering I had done extreme martial arts (including jiu jitsu) for years prior, as well as 5 years of reinforcing steel full time in my 20s, probably the hardest job on the back you can find. No pars defect like mine would possibly have allowed this--ergo it was impossible that I had had the defect since birth. I did however have an asymptomatic congenital spina bifida occulta that made me more susceptible to a pars fracture. In 2014 in one instant, I went from having the strongest back people I knew said they'd ever seen, to being unable to safely bend over and tie my shoe without a non-negligible risk of my spine slipping randomly (which would lead to weeks of pain after each occurrence). This was due to the unilateral L5 pars defect, otherwise known as spondylolysis. It was when lying in pain on the floor 4 years later after maybe the 6th spine slippage event post injury, that I had had enough, and resolved to have surgery. If Canada's "universal health care" said no, I would make lemonade from lemons, and find the very best surgeon in the world at pars repairs. That was Dr. Donald Corenman. Dr. Corenman back in 2018 ran a website https://neckandback.com/ that dedicated many pages to the science of every aspect of pars repairs, from eligibility (good discs on MRI), to best surgical techniques (minimal open compared to minimally invasive), best imaging to use (i.e., O-Arm with Stealth imaging vs. older fluoroscopy), the ideal amount of BMP to use and why not use too much or too little, and much more, all to do with pars repairs, pages upon pages of his site just on the pars, with scientific references and his own extensive expert opinion. As a health research statistician, I was very impressed with this. It was in stark contrast to the websites of other spine surgeons which barely gave the pars a word or two, focusing almost exclusively on fusions. I had found the best surgeon in the world for pars repairs, and so after Dr. Corenman personally screened my MRI to ensure my discs were healthy, I booked the surgery.

Being 46 years old at the time of surgery in 2018, with a 4-year-old pars fracture from 2014 combined with a congenital SBO meant my pars fragment was somewhat atrophied, but it was "very solid", said Dr. Corenman in the operative report. Nevertheless, it was challenging with two things to fix, the pars and SBO, and OR time was around 4 hours. Recovery over the following months was guided by a very clear "Spine binder" from the Steadman Clinic with strict rules of "no BLT" (no bending, lifting or twisting), and illustrated physiotherapy guidelines. They even warned patients to avoid fish oil supplements, which could excessively dampen inflammation and hence slow bone healing. They answered many questions I had during months of recovery, with responses coming from the very supportive Lori Fugate (then director of Dr. Corenman's practice), and Ehrich Bean (then physician's assistant at the practice), as well as a couple calls with Dr. Corenman himself after two of the CT scans. Ehrich Bean offered great advice for taking the spine binder conservatively due to the nature of pars repairs vs. fusions. The final post-op CT scan I had was a couple weeks ago at 34 months post-op, and Dr. Corenman had retired, but I got a very positive and informative call from Eric Strauch (current PA at the Steadman Clinic under Dr. Corenman's replacement there, and who had also worked with Dr. Corenman previously). The staff at the Steadman Clinic were extremely supportive all the way through the process. I should mention, the local Canadian spine surgeon did offer me very good post-operative support including antibiotics as needed to deal with a mild surface incision-site infection early on, booking numerous x-rays when I felt something was amiss, as well as booking all four of my post-op CT scans. I am very grateful for that support also.

My final result shows plenty of solid bone across the pars and a healed SBO, with my vertebral body now a solid bone ring instead of being broken at two places as it was pre-op. Does my spine hold up in the real world? You bet! I have recently dug and moved several yards of dirt and sand and gravel by myself (shovel and wheelbarrow!) to fix our water main, pulled roots from the yard, moved several "portable" (these are HUGE) air conditioners up several flights of stairs my myself, and lifted weights. I now run 2 miles (3.2 KM) several times weekly with a hard 100 meter dash in the middle. I bend deeply before each run I go on, with no spine slippage. My spine feels amazing. I can bend over to do exercise, or real word tasks, with no risk of spine slippage.

My sincere thanks to God, Dr. Donald Corenman, Lori Fugate, Ehrich Bean, Eric Strauch, and the Steadman Clinic, as well as the Canadian spine surgeon who offered me excellent post-operative care back in Canada. You have all given me a new lease on life.

Sincerely,
Eric S

Robert S

May 11, 2021

by Robert S on Donald Corenman, MD, DC

Back Fusion Surgery

I had my entire lumbar spine fused in November of 2018. I had scoliosis , with pinched nerves that were so painful I could hardly walk - and standing for more than a few minutes was impossible. Even sitting was painful.
The fusion surgery produced immediate relief! And the recovery was much easier than I expected.
To this day I can do all the activities I love from hiking, to standing in a stream fly fishing to riding my bike long distances - or just walking down the street with my wife.
Kudos to Dr. Corenman and his staff, (including the two Erics) for taking such good care of me!

Leslie R

Jul 9, 2020

by Leslie R on Donald Corenman, MD, DC

TLIF

I had my TLIF surgery on 6/24/2020 by Dr. Corenman, I can not say enough good things about the Dr or his staff. I was always treated with respect and explained everything throughly, that made it easy for everyone to understand. I highly recommend Dr. Corenman and the Steadman Clinic.

Submit your review
First Name, Last Initial:
Email:
Review Title:
Rating:	1 2 3 4 5
Review:

Check this box to confirm you are human.
Submit Cancel

An Overview of Posterolateral Fusion (PLF)

Motion and Pedicle Screws

Are you a candidate for posterolateral fusion (PLF)?

Indications for Posterolateral Fusion

Related Content

About the Author: Donald Corenman, MD, DC