What is Minimally Invasive Spinal Fusion Surgery?
Lumbar spinal fusion surgery is a procedure used to treat a variety of conditions of the lumbar spine (lower back). This article will focus on minimally invasive lumbar fusion surgery, although open lumbar fusion incorporates some of the same steps.
Why Might I Need Minimally Invasive Spinal Fusion Surgery?
Minimally invasive lumbar fusion may be used to treat a variety of conditions. These include but are not limited to:
- Lumbar instability
- Degenerated lumbar discs
- Back pain
- Recurrent herniated discs
- Failed back syndrome
The most common levels in the spine requiring treatment are L4-5 & L5-S1 Spinal Fusion Surgery. Many patients requiring lumbar fusion surgery also have pinched nerves from herniated discs or spinal stenosis. As a result, the surgery is often performed in conjunction with microlumbar discectomy or lumbar laminectomy.
What Happens During Minimally Invasive Spinal Fusion Surgery?
Minimally invasive spine fusion surgery involves making an approximately 1-inch skin incision to one side of the middle of the back at the surgical level. The location of the incision is often confirmed by an intraoperative X-ray, using fluoroscopy. Tubular retractors are sequentially placed over dilators. This splits the muscles, allowing access to the spine without having to strip as much muscle off the spine itself. Postoperative pain and muscle injury are minimized.
After the initial dilator is placed on the lamina of the spine, larger dilators are progressively applied. This gradually increases the size of the exposure to allow enough room for the surgical procedure. A retractor is then placed over the dilators to hold back soft tissue and the dilators are removed. A microscope is then used for the rest of the decompression and fusion. Use of a microscope improves surgical lighting and vision, making the lumbar fusion surgery more precise and accurate.
L4-5 & L5-S1 Spinal Fusion Surgery
Lumbar fusion may involve posterolateral fusion (PLF) with or without transforaminal lumbar interbody fusion (TLIF). If TLIF is performed, then laminectomy and factectomy is performed using a microscope. The spine is then decompressed and the disc is exposed. Using specially designed instruments, the disc is incised and removed. The endplates of the vertebrae are exposed. A bone graft is then placed between the vertebrae. This bone graft then usually heals, forming a solid bridge of bone connecting the levels. Posterolateral bone is usually added to strengthen the fusion.
Titanium screws are then placed in the bones above and below the graft. Connecting rods are then placed and the screws tightened onto the rods, making the construct solid. X-ray is used to confirm the placement of the screws. At the Texas Spine & Neurosurgery Center, we have pioneered the use of intraoperative neuromonitoring in minimally invasive spinal fusion. We have developed a technique that has been shown to give a very high level of accuracy to pedicle screw placement. This technique also helps keep radiation exposure low to the patient and surgical team. Thus the overall safety of lumbar fusion procedures may be significantly improved.
The bone graft may be obtained from the patient's hip bone, known as iliac crest graft. Some patients' insurance will cover use of bone morphogenic protein (BMP). This is a recombinant DNA product that can replace iliac crest graft in some cases. This may avoid pain associated with hip graft harvesting. Local bone or cadaver bone may also be used in some cases.
Schedule a Consultation to Discuss Treatment Options
Minimally invasive back surgery may not be appropriate under certain situations. In patients who have already had a lumbar fusion surgery, open back surgery is often required. Some patients may be too obese for minimally invasive surgery or have a spinal deformity. Also, some patients may be better treated with an anterior lumber interbody fusion, instead of L4-5 or L5-S1 fusion surgery.
Not all patients and not all conditions can be treated via a minimally invasive lumbar surgery approach. By scheduling a consultation with one of our Houston Neurosurgeons he will be able to assess your specific situation and background and decide if surgery is appropriate for you. Make an appointment today – (281) 313-0031.
Please take a look at our patient information if you have any questions about insurance, forms, or what to bring to your appointment.